SCHOOL OF BIOLOGICAL SCIENCES



Researcher : Arrigoni JR JE

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predat or on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.


Researcher : Attanayake MAS.A.

List of Research Outputs

Attanayake M.A.S...A... , Ratnayake R.M.C. and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Attanayake M.A.S...A... and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpi folia (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Bao J

List of Research Outputs

Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.


Researcher : Bao WW

List of Research Outputs

Bao W.W. , Qiu J.W., Lam M.H.W. and Leung K.M.Y. , Acute toxicities of five commonly used antifouling booster biocides to selected tropical/subtropical marin e species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Acute toxicities of zince pyrithione alone and in combination with copper to marine autotrophic species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City Universi ty of Hong Kong, Hong Kong . 2010.
Bao W.W. , Leung K.M.Y. and Lui G.C.S. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Leung K.M.Y. and Bao W.W. , A unifying model for predicting temperature-dependent toxicity of pollutants: an insight to the interacting effect of climate change and chemical pollution, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Brooks JD

List of Research Outputs

Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.


Researcher : Bugler-Lacap DC

List of Research Outputs

Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.
Wong K.Y. , Lau C.Y. , Bugler-Lacap D.C. , Aitchison J.C. , Cowan D.A. and Pointing S.B. , Endolithic microbial colonization of limestone in a high-altitude arid environment, Microbial Ecology . Springer Science, 2009, 59: 689-699.


Researcher : Cai Y

Project Title: An investigation on inhibitory effect and primary mechanism of natural phenolic antioxidants against acrylamide formation in fried and baked carbohydrate-ri ch foods
Investigator(s): Cai Y, Corke H
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2008
Abstract:
(1) To develop a new effective and safe approach to significantly inhibit or reduce acrylamide levels in fried and baked carbohydrate-rich foods through addition of natural phenolic antioxidants; (2) To eval uate inhibitory effect of different natural phenolic antioxidants from common dietary plants against acrylamide formation in fried and baked carbohydrate-rich foods; (3) To search for strong natural inhibitors to effectively reduce acrylamide levels in fried and baked carbohydrate -rich foods; (4) To investigate primary mechanism of action of the strong natural inhibitors in reducing acrylamide levels during heating of an asparagine-glucose model system; (5) To provide a work basis for further study. We will continue tests in more model food systems and in more practical application in fried and baked carbo hydrate-rich foods.


Project Title: 14th World Congress of Food Scie nce and Technology Effects of phytochemicals on reduction of acrylamide in an asparagine/glucose model system
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2008
Abstract:
N/A


Project Title: Screening and evaluation of novel acrylamide-reduced ingredients for development of health y bakery products
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2009
Completion Date: 06/2010
Abstract:
Formation and reduction of the potentially toxic acrylamide during baking or frying of carbohydrate-rich foods has been an important worldwide topic of food safety concern. The Food and Agriculture Organization (FAO) and World Health Organization (WHO) of the United Nations have concerned the risk of acrylamide in foods since 2002. They concluded in 2005 that acrylamide in foods was a potential health hazard and its most important toxic effect may be the cancer risk (Taeymans et al., 2004; INFOSAN, 2005; Zhang and Zhang, 2007). The Joint FAO/WHO Food Standards Programme Codex Committee organized the first session about ‘Proposed Draft Code of Practice for the Reduction of Acrylamide in Foods’ in April 2007 in Beijing. This draft code for limits for acrylamide focused on potato and cereal products. The Food and Environmental Hygiene Department (FEHD) of Hong Kong SAR assessed the levels of acrylamide ( <10-2600 ug/kg) in fried and baked carbohydrate-rich foods (e.g. potato crisps, chips, cookies/biscuits, breads, and cereal snacks) collected in local markets in 2003 and 2006 (Leung et al., 2003; CFS and CC, 2006). The results showed that some foods (e.g., potato crisps/ch ips, biscuit-related products, wheat/rye flour-based crisps/breads) contained significant amounts of acrylamide (200-1700 ug/kg). To minimize the risk of acrylamide, the Center for Food Safety (CFS) and the Consumer Council (CC) of Hong Kong has appealed to institutions and food industries to research and develop methods and techniques to reduce acrylamide in fried and baked carbohydrate-rich foods (CFS and CC, 2006). Since fried potato products could form higher levels of acrylamide than bakery products (e.g. breads and biscuits), previous acrylamide-reduced studies focused on potato products (mainly potato crisps and French fries), but the fewer relevant studies on bakery products were conducted (Zhang and Zhang, 2007; Friedman and Levin, 2008). Investigation of impact factors on the formation and reduction of acrylamide in fried and baked carbohydrate-rich foods included processing conditions (pH, heating time and temperature), concentration of acrylamide precursors (mainly asparagine and glucose), and chemical/food additives, etc. Some progresses on reduction of acrylam ide have been achieved. However, most of the current methods and techniques have not been used in food industry (especially production of bakery products) and some chemical additive pretreatments could generate new hazards in the final food products. Although bakery products (mainly breads and biscuits/cookies) contain lower levels of acrylamide (~100-720 ug/kg) than fried potato products (~250-1000 ug/kg) (CFS and CC, 2006), the acrylamide in breads and biscuits is still a potential health risk because consumers daily eat these conventional foods and can be frequently exposed to the acrylamide. Furthermore, fewer acrylamide-reduced studies have been currently conducted on bakery products than on potato crisps and French fries. Thus, it is necessary not only to pay attention to the risk of acrylamide in bakery products but also to find new materials an d safe approaches to reduce their acrylamide levels for minimizing the risk of acrylamide to consumers. The technological challenge of this project is how to significantly reduce acrylamide in bakery products while avoiding significant changes in the sensory quality of target products caused by addition of acrylamide-reduced in gredients. The objectives of this project are: (1) To select various kinds of functional materials (e.g. oligosaccharides, non-starch polysaccharides, inulin, resistant starch, various grain fibers, soymilk/protein hydrolysates, and phytochemicals) for determining their acrylamide-reduced levels in an asparagine/glucose model system in order to screen novel acrylamide-reduced ingredients; (2) To evaluate the acrylamide-reduced effectiveness of the primarily selected ingredients in bakery products (mainly breads and biscuits) for screening the better ones for further experiment; (3) To investigate the synergic effects of the better acrylamide-reduced ingredients mixed in breads and biscuits; (4) To optimize the levels/formulations of the better functional ingredients and the processing procedures of the healthy biscuits and breads with the reduced 50-80% acrylamide and to set up the standard processing protocols of the relevant food products; (5) To conduct sensory evaluation (e.g., texture, crispness, crust, color, flavor/taste, overall acceptability, etc.) of the final products with low level of acrylamide to meet consumer acceptability. The ultimate purpose of this project is that end-users of our studied acrylamide-reduced ingredients can use these for further development and production of healthy bakery products to minimize the risk of acrylamide to consumers in the Greater China region including Hong Kong and in the world. References cited are listed in the attached file.


Project Title: 6th International Congress on Pi gments in Food Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Cai Y. , Ke J.X. and Corke H. , MALDI-QIT-TOF MS determination of proanthocyanidins in crude extracts of selected dietary plants and medicin al herbs (Abstract), Global Chinese Health (Functional) Food Symposium 2009 (Hong Kong) . 2009.
Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prosta te cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Xiong G.Q., Cheng W., Ye L.X., Du X., Zhou M., Lin R.T., Geng S.G., Chen M.G., Corke H. and Cai Y. , Effects of konjac glucomannan on physicochemical properties of myofibrillar protein and surimi gels from grass carp ( Ctenopharyngodon idella ), Food Chemistry . 2009, 116 (2): 413-418.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Chak STC

List of Research Outputs

Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Thiel M., Chak S.T.C. and Dumont C. , Mating behavior of the dancing shrimp Rhynchocinetes brucei (Decapoda: Caridea), Journal of Crustacean Biology . 2010, 33: 580-588.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Chan KH

List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.


Researcher : Chan KK

List of Research Outputs

Poon D., Chan K.K. and Williams G.A. , Spatial and temporal variation in the diets of the crabs Metopograpsus frontalis (Grapsidae) and Perisesarma bidens (Sesarmidae): implications for mangrove food webs., Hydrobiologia . 2010, 638: 29-40.


Researcher : Chan KY

List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Chan LL

Project Title: Algal Toxins: Development of Analytical Bioassay Detection Methods and Assessment of Environmental Transfer in Marine Food Webs
Investigator(s): Chan LL
Department: School of Biological Sciences
Source(s) of Funding: Collaborative Research Fund (CRF) - Group Research Project
Start Date: 06/2009
Completion Date: 10/2010
Abstract:
1) Collect toxic and non-toxic fish and shellfish species from Maine and the west coast of the USA, Shenzhen, China, and the Republic of Kiribati in conjunction with collaborating institutions; 2) Measure toxins responsible for paralytic shellfish poisoning (PSP) in the collected shellfish species using established high-performance liquid chromatography-mass spectrometry (HPLC-MS) and bioassay methods; 3) Develop and validate an instrumental method and bioassays for measuring toxins involved in ciguatera fish poisoning (CFP), and develop commercial standards; 4) Use these optimized methods to develop a rapid testing protocol for fish and shellfish for human health protection; 5) Compare gene and protein expression profiles between toxic and non-toxic shellfish/fish species, and in shellfish/fish that retain toxins for long periods, using genomic and proteomic techniques in order to determine why some shellfish or fish species are toxic while others are not; and 66) Use molecular and stable isotope and fatty acid methods to determine the sources, dynamics and fluxes of PSP and CFP toxins in marine food webs/ecosystems.




Researcher : Chan MN

List of Research Outputs

Xi Y. , Huang B. , Djurisic A. , Chan M.N. , Leung F.C.C. , Chan W.K. and Au D.T.W., Electrodeposition for antibacterial nickel-oxide-based coatings, Thin Solid Films . Amsterdam, Elsevier B.V., 2009, 517: 6527-6530.


Researcher : Chao J

List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatechin-3 -gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methyl ated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Chao J

List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatec hin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Chen Q

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidylcholin e and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Chen SF

Project Title: Metabolic engineering for enhanced astaxanthin biosynthesis in Chlorella zofingiensis (Chlorophyta)
Investigator(s): Chen SF, Huang J
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
To establish a chlorella transformation system; to introduce a heterologous carotenoid hydroxylase gene into C. zofingiensis ; to study the regulation of astaxanthin biosynthesis in the engineered host; to maximize the production of astaxanthin in the genetically manipulated C. zofingiensis .


Project Title: Genetic enineering of a green alga l phytoene desaturase for herbicide resistance and its use as a selectable marker for nuclear transformation
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2008
Completion Date: 09/2009
Abstract:
The eukaryotic green algae are photoautotrophs, requiring only sunlight, carbon dioxide, water and basic nutrients for maximal growth. Because they potentially provide all the benefits of higher plants with large-scale microbiol production approaches, green microalgae may be an attractive alternative to the other microbial systems currently in use. Microalgae have already served as a major natural source of valuable molecules including carotenoids, long-chain polyunsaturated fatty acids and phycocolloids. In recent years, there has been a surge of interest in microalgal metabolites as a source of novel molecules. However, it is difficult to produce stable transformants of most microalgae due to the lack of proper selectable markers and promoters to drive heterologous gene expression. Chlamydomonas reinhardtii is a widly used model system for basic biological and ecological studies, especially those that cannot be investigated in bacteria and yeast (Rochaix, 1995). The recently developed techniques for nuclear and organelle transformation (Boynton et al., 1988; 1993; Kindle, 1990) have greatly expanded the use of this alga as a model system. However, it is difficult for C. reinhardtii to express heterologous genes. Therefor e, the development of dominant selectable markers is still severely hampered. Efficient transformation systems for algae commonly rely on homologous genes that complement auxotrophic mutations which are unavailable for most algae. For the expression of heterologous genes, homol ogous promotor and 3' regions providing a cognate polyadenylation signal are highly required. Up to date, only a few selectable markers are available for a few model organisms, such as the green alga C. reinhardtii, the diatom Pha eodactylum tricornutum, etc. Compared with higher plants, the transformation of algae is still in its infancy because no unviversal tools (e.g. expression cassette and selectable markers) as those used in higher plants (e.g. 35S promoter and Agrobacterium transformation system) are available for algae. Carotenoids are essential components of the photosynthetic apparatus. They participate in light harvesting and protect the chloroplasts from the harmful effect of single oxygen formed during photosynthe sis (Windhovel et al., 1994). The enzyme phytoene desaturase (PDS) is the main target for herbicides that prevent the formation of zeta-carotene, resulting in the degradation of chlorophyll and the destruction of chloroplast membr anes. Mutations (some amino acid substitutions) of the cyanobacterium Synechococcus PDS, the aquatic weed Hydrilla verticillata PDS resulted in herbicede-resistant PDS enzymes (Chamovitz et al., 1991; Michel et al., 2004), and have conferred herbicide resistance when expressed in plants (Wagner et al., 2002; Arias et al., 2006). We hypothesize that similar amino acid substitutions in PDS of eukaryotic algae could also resist to herbicide. Thus, the PDS from microalgae can be modified as dominant selectable markers used for genetic engineering of biotechnologically important microalgae for which no successful genetic manipulation is available up to date. The purpose of the proposed project is to develope a dominant selectable marker for nuclear transformantion of microalgae by modifying a homologous PDS gene that will confer herb icide resistance when expressed in algae. To achieve this project aim, the gene coding for the carotenoid biosynthetic enzyme PDS from C. reinhardtii will be isolated. This gene will be mutated and functionally analysed in recombi nant E. coli and in vitro assay for herbicide resistance. Herbicide-resistant PDSs will be inserted into C. reinhardtii expressing cassete (Stevens et al. 1996; Cerutti et al., 1997; Schroda et al., 2000) and introduced into the algal cells using the method introduced by Kindle (1990). Herbicide resistance and pigment profiles of transformants will be assessed. References 1. Arias , R.S., Dayan, F.E., Michel, A., Howll, J., and Scheffler B.E. (2006) Characterization of a higher plant herbicide-resistan t phytoene desaturase and its use as a selectable marker. Plant Biotechnology Journal 4, 263-273. 2. Boynton, J.E., Gillham, N.W., Harris, E.H., Hosler J.P. Johnso, A.M., Jones, A.R., Randolph-Anderson, B.L., Robertson, D. Klein., T.M., Shark, K.B., and Sanford, J.C. (1988) Chloroplast transformation in Chlamydomonas with high velocity microprojectiles. Science 240, 1534-1538. 3. Cerutti, H., Johnson, A.M., Gillham, N.W. and Boynton, J.E. (1997) A eubacterial gene conferring spectinomycin resistance on Chlamydomonas reinhardtii: integration into the nuclear genome and gene expression. Genetics, 145, 97-110. 4. Chamovitz, D., G. Sandmann, and J. Hirschberg. (1993) Molecular and biochemical characterizat ion of herbicide-resistant mutants of cyanobacteria reveals that phytoene desaturation is a rate-limiting stepin carotenoid biosynthesis. J. Biol. Chem. 268, 17348-17353. 5. Kindle, K.L. (1990) High-fregquency nuclear transformat ion of Chlamydomonas reinhardtii. Proc. Natl. Acad. Sci. USA 87, 1228-1232. 6. Rochaix, J.-D. (1995) Chlamydomonas reinhardtii as the photosynthetic yeast. Annu. Rev. Genet. 29, 209-230. 7. Schroda, M., Blocker, D., and Beck, C.F. (2000) The HSP70A promoter as a tool for the improved expression of transgenes in Chlamydomonas. Plant J. 21, 121-131. 8. Stevens, D.R., Rochaix, J.-D. and Purton, S. (1996) The bacterial phleomycin resistance gene ble as a dominant selectable marker in Chlamydomonas. Mol. Gen. Genet. 251, 23-30. 9. Wagner T., Windhovel, U., and Romer. S. (2002) Bansformation of tobacco with a mutated cyanobacterial phytoene desaturase confers resistance to bleeching herbicides. Z Naturforsch 57, 671-679. 10. Windhovel, U., Geiges, B., Sandmann, G., and Boger, P. (1994) Expression of Erwina Uredovora phytoene desaturase in Synechococcus PCC 7942 leading to resistance against bleaching herbicides. Plant Physiol. 102, 119-125.


Project Title: Directed evolution of carotenoid ketolase and hydroxylase for investigating the molecular basis of enzyme function and astaxanthin biosynthesis
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2008
Abstract:
(1) to investigate the BKT activity toward zeaxanthin for astaxanthin production; (2) to investigate the CHYb activity toward beta-carotene for zeaxanthin production ; (3) to study the molecular basis of the enzymes for activity and substrate specificity; (4) to elucidate the evolution of astaxanthin biosynthesis.


Project Title: Chloroplast genome engineering of Chlamydomonas reinhardtii for metabolic pathway study
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Abstract:
Astaxanthin is a red ketocarotenoid that occurs only in a limited number of bacteria, fungi, and in certain unicellular algae (Boussiba, 2000). This red pigment has been widely used as a feed supplement in aquaculture and poultry industries (Johnson and Schroeder 1995). In addition, due to its high antioxidant activity, astaxanthin has also been used commercially as nutraceuticals and for cosmetic and pharmaceutical purposes (Lorenz and Cysewski 2000, Guerin et al. 2003). The unicellular green microalga Haematococcus pluvialis reveals the highest astaxanthin accumulation (up to 4% of dry biom ass) (Boussiba et al., 1992). H. pluvialis has served as a natural source of astaxanthin. The slow growth rate and lack of a genetic transformation system of this alga, however, limit its application. In contrast, other astaxanthin-producing microorganisms have much lower cellular astaxanthin content. With very few exceptions, higher plants normally do not synthesize astaxanthin. In recent years, the carotenoid biosynthetic pathway in some plants has been extended to astaxanthin by nuclear transformation of a heterologous β-carotene ketolase (bkt) gene. However, in all cases, only trace amounts of astaxanthin were synthesized in the transgenic plants. Knowledge of ketocarotenoid biosynthesis is very limited, which greatly hinders the exploitation and application of astaxanthin-producing organisms and transgenic plants as natural sources of ketocarotenoids on an industrial scale. Recently, biosynthesis of astaxanthin in tobacco leaves was achieved by plastid transformation, which highlights the utility of plastid transformation as an excellent tool to drastically alter carotenoid compositions and contents in algae and crop plants. (Husunuma et al., 2008). The unicellular geen alga Chlamydomonas reinhardtii is an important model organism for studies of photosynthesis and pigment biosynthesis (Harris 1989). No astaxanthin has been reported to occur in C. reinhardtii although its genome contains an open reading frame with strong similarity to BKT enzymes from the green algae H. pluvialis and Chlorella zofingiensis (Grossman et al. 2004, Huang et al. 2006a, b). We have recently characterized the putative Chlamydomonas BKT and found it to possess ketolase activity. RT-PCR detection revealed that the expression of the bkt gene was too low to trigger the cell to produce astaxanthin. We therefore hypothesized that the low expression of the bkt gene is the limiting factor for C. reinhardtii to synthesize ketocarotenoids. To prove the hypothesis, we introduced a Haematococcus bkt into C. reinhardtii by nuclear transformation. However the genetic modified cells failed to produce significant amounts of ketocaroteno ids even though all the elements required for optimal transcription and translation (promoter, intron and other regulatory regions) had been included in the chimeric gene construc tion. RT-PCR detection revealed very low expression of the transgene, possibly resulting from the so-called gene silencing. Very recently, robust expression of heterologous genes has been achieved in Chlamydomonas chloroplast by plastid transformation (Mayfield et al., 2007). Transgene expression from the chloroplast genome offers several advantages over nuclear transformation, including high-level accumulation of foreign proteins, transgene stacking in operons and a lack of epigenetic interference with the stability of transgene expression (Bock 2007). Thus we propose to solve the problem of low expressio n of transgenes in C. reinhardtii by chloroplast genome engineering. The purpose of this proposed research is to develop a model system for the study of astaxanthin biosynthesis in green algae. The unicellular green alga C. reinhardtii, to which its chloroplast DNA can be easily transformed, will serve as a target organism and genetically be engineered by introducing a novel copy of bkt gene into its chloroplast via plastid tra nsformation. It is expected that the modified cells will produce and accumulate astaxanthin in the chloroplast which takes up about half of the cell volume. The established system will help to reveal the regulation of astaxanthin biosynthesis in the green alga H. pluvialis, the organism with the richest astaxanthin content in nature. References Bock R. (2007) Plastid biotechnology: prospects for herbic ide and insect resistance, metabolic engineering and molecular farming. Curr. Opin. Biotechn. 18: 100-106. Boussiba (2000) Carotenogenesis in the green alga Haematococcus pluvialis: cellular physiology and stress response. Physiol. Plantarum. 108:111-117. Boussiba, S., Fan, L. & Vonshak, A. 1992. Enhancement and determination of astaxanthin accumulation in green alga Haematococc us pluvialis. Method Enzymol. 213: 386-391. Grossman, A. R., Lohr, M. & Im, C. S. 2004. Chlamydomonas reinhardtii in the landscape of pigments. Annu. Rev. Genet. 38:119-173. Guerin, M., Huntley, M. E., & Olaizola, M. 2003. Haematococcus astaxanthin: applications for human health and nutrition. Trends Biotechnol. 21:210-216. Harris, E. H. The Chlamydomonas Sourcebook, Academic Press, San Diego, 1989 Huang, J.C., Wang, Y., Sandmann, G. & Chen, F. 2006a. Isolation and characterization of a carotenoid oxygenase gene from Chlorella zofingiensis (Chlorophyt a). Appl. Microbiol. Biotechnol. 71:473-9. Huang, J.C., Chen, F. & Sandmann, G. 2006b. Stress-related differential expression of multiple beta-carotene ketolase genes in the unicellular green alga Haematococcus pluvialis. J. Biotechnol. 122:176-85. Johnson, E. A. & Schroeder, W. A. 1995. Microbial carotenoids. Adv. Biochem. Eng . Biotechnol. 53:119-178. Lorenz, R. T. & Cysewski, G. R. 2000. Commercial potential for Haematococcus microalgae as a natural source of astaxanthin. Trends Biotechnol. 18:160-167. Mayfield S.P., Manuell A.L, Chen S. et al. (2007) Chlamydomonas reinhardtii chloroplasts as protein factories. Curr. Opin. Biotechn. 18:126-133.


Project Title: Assess the potential of the green microalgae Chlorella species as biodiesel feedstocks
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Petroleum fuels are recognized as unsustainable due to their depleting supplies and contribution to global warming (Chisti, 2008). Renewable biofuels are promising alternatives to petroleum fuels, among which biodiesel has attracted the most attention in recent years (Knothe et al., 1997, 2006; Fukuda et al., 2001; Gerpen, 2005; Meher et al., 2006; Hu et al., 2008). Biodiesel is a diesel-equivalent fuel derived from biological feedstocks and is chemically referred to as a fatty acid methyl ester (FAME). In comparison with traditional fuels, biodiesel is carbon neutral, contributes less emission of gaseous pollutants and so is environmentally beneficial (Ma and Hanna, 1999 ). Current biodiesel is mainly derived from vegetable oils, animal fats and waste cooking oils (Knothe et al., 1997; Lang et al., 2001; Al-Widyan et al., 2002; Zhang et al., 2003; Demirbas, 2005). However, such sources of biodiesel cannot meet the existing need for transport fuels as immense cultivation lands have to be taken up for oil crops (Chisti, 2007). The relatively high cost of using vegetable oil as feedstock also restricts the commercialization of biodiesel (Lang et al., 2001). Microalgae are sunlight-driven cell factories that convert carbon dioxide to potential biofuels, foods, feeds and high-value bioactives (Spol aore et al., 2006). Microalgae have being considered as feedstocks for biodiesel production because of their rapid growth and high contents of lipids (Chisti, 2007; Hu et al., 2008). Unlike oil crops, microalgae can be easily cultured in outdoor ponds or bioreactors (Chen, 1996; Del Campo et al., 2007; Pruvost et al., 2009), making it be a more competent alternative to oil crops in biomass production. When consider a microalgal feasibility for mass biodiesel production, two key factors, namely cell biomass and lipid content are essential for the initial assessment. Thus microalgae with fast-growth and high lipid productivity are desirable for biodiesel exploitation. The green microalgae Chlorella species consist of about 10 species, most of which can grow fast photoautotrophically, mixotrophically and heterotrophically (Chen, 1997; Shi et al., 2002; Ip et al., 2004; Miao and Wu, 2004). High contents of lipids have been reported in some of the species, such as C. vulgaris and C. protothecoides (Miao and Wu, 2004; Liu et al., 2008; Hsieh and Wu, 2009). Compared with photoautotrophic culture, heterotrophic culture can obtain much higher biomass as demonstrated by C. zofingiensis that at least 5-fold biomass was obtained by heterotrophically culturing the alga using glucose as sole carbon and energy source (Sun et al., 2008). The heterotrophic ability of Chlorella species also eliminates light requirement that is essential for photoautotrophic microalgae and therefore reduces the cost in the production process (Borowitzka, 1999). The purpose of this proposed project is to assess several Chlorella species for their potential as novel sources of biodiesel by the investigation of their heterotrophic growth and fatty acid productivity with various organic carbon sources and different stress conditions. References Al-Widyan, M.I., Al-Shyoukh, A.O., 2002. Experimental evaluation of the transesterification of waste palm oil into biodiesel. Bioresour. Technol. 85, 253-256. Borowitzka, M.A., 1999. Commercial production of microalgae: ponds, tanks, tubes and fermenters. J. Biotechnol. 70, 313-321. Chen, F., 1996. High cell density culture of microalgae in heterotrophic growth. Trends Biotechnol. 14, 421-426. Chisti, Y., 2008. Biodiesel from microalgae beats bioethanol. Trends Biotechnol. 26, 126-31. Del Campo, J.A., Garcia-Gonzalez, M., Guerrero, M.G., 2007. Outdoor cultivation of microalgae for carotenoid production: current state and perspectives. Appl. Microbiol. Biotechnol. 74, 1163-1174. Demirbas, A., 2005. Biodiesel production from vegetable oils via catalytic and non-catalytic supercritical methano l transesterification methods. Prog. Energy. Combust. Sci. 31, 466-487. Fukuda, H., Kondo, A., Noda, H., 2001. Biodiesel fuel production by transesterification of oils. J. Biosci. Bioeng. 92, 405-416. Gerpen, J.V., 2005. Biodiesel processing and production. Fuel Process. Technol. 86, 1097-1107. Hsieh, C.-H., Wu, W.-T., 2009. Cultivation of microalgae for oil production with a cultivation strategy of urea limitation. Bioresour. Technol. 100, 3921-3926. Hu, Q., Sommerfeld, M., Jarvis, E., Ghirardi, M., Posewitz, M., Seibert, M., Darzins, A., 2008. Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances. Plant J. 54, 621-639. Ip, P.F., Wong, K.H., Chen, F., 2004. Enhanced production of astaxanthin by the green microalga Chlorella zofingiensis in mixotrophic culture. Process Biochem. 39, 1761-1766. Knothe, G., 2005. Dependence of biodiesel fuel properties on the structure of fatty acid alkyl esters. Fuel Process. Technol. 86, 1059-1070. Knothe, G., Dunn, R.O., Bagby, M.O., 1997. Biodiesel: the use of vegetable oils and their derivatives as alternative diesel fuels. in: B.C. Saha, J. Woodward (Eds.), Fuels and Chemicals from Biomass. American Chemical Society, Washington, D.C., pp. 172-208. Lang, X., Dalai, A.K., Bakhshi, N.N., Reaney, M.J., Hertz, P.B., 2001. Preparation and characterization of bio-diesels from various bio-oils. Bioresour. Technol. 80, 53-62. Liu, Z.-Y., Wang, G.-C., Zhou, B.-C., 2008. Effect of iron on growth and lipid accumulation in Chlorella vulgaris. Bioresour. Technol. 99, 4717-4722. Ma, F., Hanna, M.A., 1999. Biodiesel production: a review. Bioresour. Technol. 70, 1-15. Meher, L.C., Vidya Sagar, D., Naik, S.N., 2006. Technical aspects of biodiesel production by transesterification--a review. Renew. Sustain. Energy Rev. 10, 248-268. Miao, X., Wu, Q., 2004. High yield bio-oil production from fast pyrolysis by metabolic controlling of Chlorella protothecoides. J. Biotechnol. 110, 85-93. Miao, X., Wu, Q., 2006. Biodiesel production from heterotrophic microalgal oil. Bioresour. Technol. 97, 841-846. Pruvost, J., Van Vooren, G., Cogne, G., Legrand, J., 2009. Investigati on of biomass and lipids production with Neochloris oleoabundans in photobioreactor. Bioresour. Technol. 100, 5988-5995. Shi, X.-M., Chen, F., 2002. High-yield production of lute in by the green microalga Chlorella protothecoides in heterotrophic fed-batch culture. Biotechnol. Prog. 18, 723-727. Sun, N., Wang, Y., Li, Y.-T., Huang, J.-C., Chen, F., 2008. Sugar-based growth, astaxanthin accumulation and carotenogenic transcription of heterotrophic Chlorella zofingiensis (Chlorophyta). Process Biochem. 43, 1288-1292. Zhang, Y., Dub, M.A., McLean, D.D., Kates, M., 2003. Biodiesel production from waste cooki ng oil: 1. Process design and technological assessment. Bioresour. Technol.


List of Research Outputs

Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Law Y.K. , Wang M. , Ma D.L. , Al-Mousa F., Michelangeli F., Cheng S.H., Ng M., To K.F., Mok O.Y.F., Ko Y.Y. , Lam S.K. , Chen S.F. , Che C.M. , Chiu P. and Ko B.C.B., Alisol B, a novel inhibitor of the SERCA pump, induces autophagy, ER-stress and apoptosis, Molecular Cancer Therapeutics . 2010, 9: 718-730.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng CY

List of Research Outputs

Cheng C.Y. , Wong E.W.P. , Yan H.H.N. and Mruk D.D. , Regulation of spermatogenesis in the microenvironment of the seminiferous epithelium: new insights and advances, Mol Cell Endocrinol . 2010, 315: 49-56.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents blood-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants , In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Cheng KW

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylate d derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylamide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng KW

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylamide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, Uni ted States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng YY

List of Research Outputs

Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Rela ted Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.


Researcher : Cheung KW

List of Research Outputs

Dudgeon D. , Mantel S...K... and Cheung K.W. , Food-web structure in small streams: do we need different models for the tropics?, Journal of the North American Benthological Society . 2010, 29: 395-412.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitami ns against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.


Researcher : Cheung MMS

List of Research Outputs

Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.


Researcher : Chiu MY

List of Research Outputs

Wu S.S. , Tong E.S.P., van de Merwe J.P. and Chiu M.Y. , Effects of 1,2 dichlorobenzene on the growth, bioenergetics and reproduction of the amphipod Melita longidactyla, Chemosphere . 2010, 80: 20-27.


Researcher : Chow BKC

Project Title: A negative feedback loop involving bile acids and Small Heterodimer Partner in controlling secretin gene expression is a key to modulate bile release
Investigator(s): Chow BKC
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
(1) To substantiate the working model for regulating secretin gene expression by bile acids in mouse; (2) use secretin receptor WT and Ko mice to investigate 2a) in vivo functions of bile acids to negatively feeedback to control secretin gene expression: 2b) in vivo functions and cellular mechanisms of secretin in the liver to activate bile flow; (3) to investigate the potential of secretin to protect or prevent bile acids-induced liver damage.


Project Title: Discovery of novel growth hormone-r eleasing hormones in vertebrates: from functions to evolution
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: France/Hong Kong Joint Research Scheme - Travel Grants
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
1) To confirm the function of the newly discovered GHRH as GH-regulator in goldfish; 2) to consolidate the proposed evolutionary scheme for three important intercellular communicators, GHRH, VIP and PACAP.


Project Title: Discovery of novel growth hormone -releasing hormone: from functions to evolution
Investigator(s): Chow BKC
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Abstract:
To confirm the function of the newly discovered GHRH as GH-regulator in goldfish; to find putative function(s) of PRP in non-mammalian vertebrates; to consolidate the proposed evolutionary scheme for three important intercellular communicators, GHRH, PACAP and VIP, based on three rounds of genome duplication early on in vertebrate evolution.


Project Title: Neuron-restrictive silencer fact or (NRSF) regulates cell-specific expression of the human secretin receptor gene
Investigator(s): Chow BKC, Lee TO
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 03/2010
Abstract:
1. To identify the location and function of neuron-restrictive silencer element (NRSE) within the hSR promoter 2. To confirm the in vitro/in vivo binding of NRSF to NRSE 3. To study the role of NRSF, by interacting with Sp-proteins, in regulating hSR expression.


Project Title: A unified on-line learning portal for Majors and Minors offered by the newly formed Scho ol of Biological Sciences
Investigator(s): Chow BKC, Pointing SB, Wong AST, Wan JMF, Lo CSC , Hau CH, Gu JD
Department: School of Biological Sciences
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 09/2008
Abstract:
Purpose of the investigation To provide on-line learning support to all biological science courses that feed all the Major/Minor programmes offered by the School. This will be unique in that it’s design will create a constantly evolving resource with a simple interface that requires no programming knowledge to operate: Individual staff will have direct access to edit the web-based noticeboards, download centres, tutorial material etc. This will not only alleviate the burden of web support on technical staff but vitally it will have valuable benefits in academic staff developm ent within the School as all can become more engaged in the development on-line learning. The project will also reinforce development of a School culture, which is vital in the early days of a merged set of departments such as these. Students will gain from a centralized resource that will enrich and add real value to their learning. Modern biological sciences rely heavily on graphical explanations and multimedia tools to conve y concepts and techniques. This is particularly relevant to areas where safety and ethical issues in biology preclude traditional practical teaching. Added value will accrue as students will be able to identify a ‘brand’ associated with the new School, and this will help to foster collegiality among students and staff who have recently come together form different departments.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Central Administration of Secretin Suppresses Food Intake in Mice
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


Project Title: THE POTENTIAL ROLE OF SECRETIN, A POSTPRANDIALLY RELEASED GUT HORMONE, IN APPETITE CONTROL
Investigator(s): Chow BKC, Chan YS, Ng SM
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To demonstrate the role of central and peripheral secretin in appetite control; 2) To investigate mechan isms through which central and peripheral SCT modulates appetite; 3) To study pathways that secretin employs to stimulate/inhibit expression of anorexigenic/orexigenic peptides.


Project Title: Modulation of secretin and secretin receptor gene expressions by angiotensin II in mouse hypothalamic cells.
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Angiotensin II (Ang II) has diverse physiological actions leading, for example, to increases in extracellular volume, peripheral vascular resistance and blood pressure, and has also been implicated in the regulation of cell growth and differentiation. In brain, the intrinsic renin-angiotensin system (RAS) is important in regulati ng blood pressure and volume homeostasis. Immunohistochemical study suggested that a large number of Ang II immunoreactive fibers and Ang II receptors (AT1 receptor) are expressed in the hypothalamic paraventricular nucleus (PVN). Actually, magnocellular neurons of the hypothalamo- neurohypophysial system (HNS) play a fundamental role in the maintenance of body water homeostasis by regulating vasopressin (Vp) expression and its secretion from the posterior pituitary in response to systemic osmotic perturbations. Recent studies by our group, however, have found that secretin, in additional to Vp, could also be released from these neurosecretory cells, where transcription of the secretin gene, as well as its receptor (SCTR) gene, are activated by hyperosmolality (1). These data indicate that the increase of secretin expression results in thirst and hence polydipsia. Interestingly, the effects of secretin in brain under water deprivation are similar to those of Ang II. It is therefore possible that secretin may act as a mediating factor in the renin-angiotensin axis. In wild-type mice, centrally administration of Ang II significantly increased secretin and SCTR transcript levels in brain. More important, in metabolic cage study, Ang II-stimulated water intake was abolished in SCTR knock-out (SCTR-/-) mice. Therefore, we proposed that secretin is involved as a component within the RAS. In our data using N42 cells, the expression levels of both secretin and SCTR were increased by treatment of Ang II. Although it has clearly been established that Sp1/Sp3 ratio and the methylation status of the promoter contribute to the expressions of both genes (2,3), the precise molecular mechanism underlying the induction of these two genes in response to Ang II has not been clarified. The present study therefore aims to identify the osmotic response elements in the secretin and SCTR promoters. To investigate the mechanism that activates secretin and secretin receptor genes after Ang II treatment, three objectives are proposed: (1) Mapping of the cis-acting elements of secretin and SCTR promoters (2) Identification of the transcription factors that mediate the osmotic response (3) Functional analysis of proposed pathways by specific inhibitors and gene silencing technique


List of Research Outputs

An X. , Ng S.M. , Xie D., Zeng Y.X., Sze J. , Wang J. , Chen Y.C., Chow B.K.C. , Lu G., Poon W.S., Kung H.F., Wong B.C.Y. and Lin M.C. , Functional characterisation of cell cycle-related ki nase (CCRK) in colorectal cancer carcinogenesis. , European Journal of Cancer . 2010, 46: 1752-1761.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Rel ated Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Lam P.Y. , Glasser G., Gaudio E., Chow B.K.C. , Onori P., Franchitto A., Carpino G., Venter J., Francis H., Mancinelli R., Kopriva S. and Alpini G., Knock out of secretin receptors reduces large cholangiocyte hyperplasia in mice with extrahepatic cholestasis ind uced by bile duct ligation., Hepatology . 2010, 52: 204-214.
Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Vaudry D., Falluel-Morel A., Bourgault S., Basille M., Burel D., Wurtz O., Fournier A., Chow B.K.C. , Hashimoto H., Galas L. and Vaudry H., Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery., Pharmacological Reviews . 2009, 61: 283-357.
Yao H. , Ng S.M. , Tucker W.O. , Tsang Y.K.T. , Man K. , Wang X.M., Chow B.K.C. , Kung H.F., Tang G. and Lin M.C. , The gene transfection efficiency of a folate-PEI600-cy clodextrin nanopolymer, Biomaterials . 2009, 30(29): 5793-5803.


Researcher : Chu H

List of Research Outputs

Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essential for chloroplast function., New Phytologist . 2010, 187: 83-105.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Chu JYS

Project Title: Identification of the first non-mammalian secretin and secretin receptor: functional evolution of this ligand-receptor pair in the transition process from aquatic to terrestrial life
Investigator(s): Chu JYS, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 09/2008
Completion Date: 02/2010
Abstract:
Secretin is the first hormone discovered in the human history. It has well-established functions in the gastrointestinal tract and central nervous system, and has recently been shown to act also as an anti-diuretic peptide in mammals. In non-mammalian vertebrates, howev er, virtually nothing is known about their sequence, structure, function, signaling mechanisms, and evolutionary origin. Recent advents in various genome projects have provide us the opportunity to identify candidate genes for this ligand-receptor pair in lower vertebrates via comparative approaches, including sequence similarity searches. One significant finding is that putative orthologous for secretin and its receptor could only be identified in tetrapods but not teleosts (Figure 1). As secretin has recently been shown to modulate body water homeostasis in mammals by regulating renal water reabsorption, we hypothesized that this ligand-receptor pair was evolved during the transition from aquatic to terrestrial habitats to deal with problems related to desiccation. The present project therefore aims to: 1) Isolate and characterize secretin and its receptor from a nonamniote vertebrate, Xenopus laevis, an amphibian that occupies a critical phylogenetic position mid-way between ascidians and mammals. 2) Investigate the functional evolution of this ligand-receptor pair in vertebrate.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Secretin: A neurosecretory factor regulating body water homeostasis
Investigator(s): Chu JYS
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


List of Research Outputs

Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.


Researcher : Chye ML

Project Title: Investigations on stress-inducible Arabidopsis acyl-CoA binding proteins
Investigator(s): Chye ML
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Abstract:
To select a lead-binding ACBP and to verify feasibi lity of its application in phytoremediation; to study Arabidopsis ACBP3 in response to phytopathogen stress and to verify its use in protection against phytopathogens.


Project Title: Outstanding Researcher Award 2006-2007
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Researcher Award
Start Date: 11/2007
Abstract:
Nil


Project Title: Characterization of a cDNA encoding a 71-kD rice acyl-CoA-binding protein
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Completion Date: 03/2010
Abstract:
Purpose: Acyl-CoA-binding proteins (ACBPs) show conservation in the acyl-CoA-binding domain and thus they can bind and transport acyl-CoA esters in lipid metabolism. The aim of this project is to characterize a potentially unusual member belonging to the family of ACBPs in the monocot, rice (Oryza sativa). This particular rice ACBP, designated OsACBP1, has a predicted chloroplast targeting sequence and two potential transmembran e domains. At present, no chloroplast targeting sequence has been identified in known plant ACBPs. In plants, de novo fatty acid biosynthesis occurs in the chloroplast and acyl-CoAs (oleoyl-CoA and palmitoyl-CoA) esters are subsequently transported via the cytosol to the endoplasmic reticulum (ER) for non-plastidial lipid metabolism. Presence of a chloroplast form of ACBP would indicate that OsACBP1 may function in acyl-CoA trafficking within the chloroplast and suggests a new role for ACBPs in this subcellular compartment. In the dicot model plant, Arabidopsis, we have characterized a family of six ACBPs but none of these include a chloroplastic form. ACBP4 and ACBP5 are candidates that mediate the cytosolic transfer of oleoyl-CoA esters originating from the chloroplast to the ER, based on our observations that recombinant His-tagged ACBP4 and ACBP5 bind oleoyl-CoA esters in vitro. In this project we will characterize the putative chloroplastic form of ACBP from rice. We will test if the predicted chloroplast targeting sequence in OsACBP1 functions in directing it to the chloroplast by using a Green Fluorescent Protein (GFP) autofluorescence tag in transient expression assays on subcellular localization. Further, we will identify the acyl-CoA esters that bind OsACBP1 in in vitro binding assays using recombinant His-tagged OsACBP1 expressed in E. coli. A His-tag will be fused to OsACBP1 to facili tate easy purification of the recombinant protein in mass production for in vitro assays with oleoyl-CoA and palmitoyl-CoA. Key issues: In Arabidopsis, six ACBPs have been identified and characterized (Leung et al., 2004). They, designated ACBP1 to ACBP6, have been subcellularly localised to various compartments but none is targeted to the chloroplast. ACBP1 and ACBP2 are localized in the plasma membrane (Chye et al., 1999; Chye et al., 2000; Li and Chye, 2003; 2004), ACBP3 is extracellularly-targeted (Leung et al., 2006) and ACBP4, ACBP5 and ACBP6 are cytosolic proteins (Leun g et al., 2004; Chen et al., 2008). These ACBPs differ in molecular mass, ranging from 10 to 73 kDa and substrate specificities for acyl-CoA esters (Leung et al., 2004; Gao et al., 2008). We have demonstrated that the genes encoding Arabidopsis ACBP1, ACBP2, ACBP3, and ACBP6, are subject to regulation by various forms of abiotic and biotic stress (Chen et al, 2008; Gao et al, 2008; Li et al., 2008; Xiao et al, 2008a, 2008b). The overexpression of ACBP1 or ACBP2 in transgenic Arabidopsis resulted in tolerance to heavy metal str ess and oxidative stress because ACBP1 and ACBP2 are associated with membrane repair (Xiao et al, 2008a; Gao et al, 2008). ACBP3-overexpressing transgenic Arabidopsis show enhanced resistance to pathogens while ACBP6-overexpressin g transgenic Arabidopsis are conferred freezing tolerance (Chen et al, 2008). ACBPs mediate lipid transfer and the manipulation of lipid composition has resulted in stress-tolerance. These initial investigations on the model plant, Arabidopsis, have many advantages including the availability of its complete genome sequence and knock-out mutants. Further, Arabidopsis has a rapi d life-cycle, is easy to transform and maintain in the laboratory. If we were to carry out similar investigations on rice, it would have taken us a longer time to achieve similar results in understanding the role of plant ACBPs because rice is difficult to transform and knock-out mutants are not easily accessible. Our eventual goal is to genetically-modify rice to stress-resistance by manipulation of the rice genome using Arabidopsis ACBPs. But before we can overexpress Arabidopsis ACBPs in transgenic rice to obtain these stress-resistant varieties by application of the principles used in the generation of stress-tolerant transgenic Arabidopsis, we should first attempt to acquire basic knowledge on the endogenous ACBP family in rice. From GenBank data, we have identified six rice genes that encode proteins conserved in the acyl-CoA binding domain. Of these, three resemble Arabidopsis ACBP6, because they consist only of an acyl-CoA-binding domain. Another has ankyrin repeats and a membrane domain, resembling Arabidopsis ACBP1 and ACBP2. However, the largest rice ACBP (71-kD), designated OsACBP1, possesses an unusual predicted structure in comparison to all known plant ACBPs. Computer predictions suggest that OsACBP1 contains kelch motifs, (resembling ACBP4 and ACBP5), as well as two transmembrane domains and an N-terminal chloroplast targeting sequence. The presence of two predicted transmembrane domains and a potential chlorop last targeting sequence is novel to plant ACBPs. There have been no reports of any ACBP subcellularly localized in the chloroplast. Problems addressed: The problems addressed in this project are: 1. to establish if the predicted chloroplast targeting sequence in OsACBP1 is functional; 2. to identify the acyl-CoA esters that bind OsACBP1. Although fatty acid biosynthesis initiates from within the chloroplast, none of our previously characterized Arabidopsis ACBPs have been localized to this subcellular compartment. Since rice is a monocot, unlike Arabidopsis, it may possibly have evolved a chloroplastic form of ACBP to facilitate an efficient transfer of acyl-CoA esters within the chloroplast to cytosolic ACBPs. To establish if the predicted chloroplast targeting sequence of OsACBP1 functions in targeting to the chloroplast, its N-terminal predicted targeting sequence consisting of the first 30 amino acids will be fused in-frame to autofluorescent protein GFP. Also, the full-length OsACBP1 peptide will be fused in-frame to GFP as comparison. The acyl-CoA substrates that bind OsACBP1 will be identified using in vitro binding assays. Oleoyl-CoA and palmitoyl-CoA will be tested because they are generated from de novo fatty acid biosynthesis inside chloroplasts. References: 1. QF Chen, S Xiao and ML Chye. 2008. Plant Physiology 148: 304-315. 2. ML Chye, BQ Huang and SY Zee. 1999. Plant Journal 18: 205-214. 3. ML Chye, HY Li and MH Yung. 2000. Plant Mol Biol: 44: 711-721. 4. W Gao, S Xiao, HY Li and ML Chye. 2008. New Phytologist doi: 10.1111/j.1469-8137.2008.02631.x 5. KC Leung, HY Li, G Mishra and ML Chye. 2004. Plant Mol Biol 55: 297-309. 6. KC Leung, HY Li, S Xiao, MH Tse, ML Chye. 2006. Planta 223: 871-881. 7. HY Li and ML Chye. 2003. Plant Mol Biol 51: 483-492. 8. HY Li and ML Chye. 2004. Plant Mol Biol 54: 233-243. 9. HY Li, S Xiao and ML Chye. 2008. J. Exp. Bot. 59: 3997-4006. 10. S Xiao, W Gao, QF Chen, S Ramalingam and ML Chye. 2008a. Plant Journal 54: 141-151. 11. S Xiao, HY Li, JP Zhang, SW Chan and ML Chye. 2008b. Plant Mol. Biol. 68: 571-583.


Project Title: The Third Asian Symposium on Pla nt Lipids (ASPL 2009) ARABIDOPSIS ACYL-COENZYME-A BINDING PROTEIN 2 INTERACTS WITH A LYSOPHOSPHOLIPASE
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 11/2009
Completion Date: 11/2009
Abstract:
N/A


Project Title: Analysis of transgenic model plants
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Purpose: Plant isoprenoids include natural compounds that promote physiological functions and defense against phytopathogens. 3-Hydroxy-3-methyl-glutaryl-CoA synthase (HMGS) is an enzyme in isoprenoid biosynthesis in eukaryotes and some bacteria. The aim of this project is to address whether isoprenoid production can be increased in transgenic plants by the overexpression of wild-type/mutant HMGS. It will also show whether physiological functions (e.g., plant growth and development) and defense against phytopathogens are consequently enhanced in HMGS-overexpressors. Key issues: Isoprenoids are one of the largest classes of natural products including sterols, sesquiterpenes, polyterpenes, carotenoids, taxol and artemisinin, and are mainly produced by plants (Bach, 1995; Roberts, 2007). Plant isoprenoids are essential for membrane biogenesis (sterols), photosynthesis (carotenoids, chlorophyll), respiration (quinones), growth and development (abscisic acid an d gibberellic acid) and in disease resistance (sesquiterpenes, brassinosteroids), and they also play significant roles in plant-environment interactions, plant-plant communication , and plant-insect interactions (Bach, 1995; Pichersky and Gershenzon, 2002). Isoprenoids such as natural rubber are economically valuable while monoterpenes (e.g., linalool) are used as flavors/fragrances in food additives. Taxol and artemisinin are important anti-cancer drugs while artemisinin is anti-malarial too. The important functions of many isoprenoids make it useful for them to be overproduced in transgenic plants. Two biosynthetic pathways synthesize isoprenoid precursors in plants, the cytosolic mevalonate (MVA) pathway (Bach 1995) and the plastid-confined non-MVA pathway (Lichtenthaler 1999; Rohmer 1999). The MVA pathway provides isoprenoids essential for growth, development and defense (Bach, 1995; Hemmerlin and Bach 1998; Hemmerlin et al. 1999). Both HMGS and HMG reductase (HMGR, Kush et al., 1990; Chye et al., 1992) catalyze the early steps in the MVA pathway. HMGS catalyzes the condensation of acetyl-CoA with acetoacetyl-CoA (AcAc-CoA) to yield HMG-CoA and HS-CoA while HMGR converts HMG-CoA to MVA. My laboratory has cloned and characterized cDNAs encoding four isoforms of Brassica juncea HMGS, designated BjHMGS1 to BjHMGS4 (Alex et al., 2000; Nagegowda et al., 2004; 2005). Brassica HMGS expression is stress-inducible and is highly expressed during early development in flower, seed and seedling, indicative of its role in development (Alex et al., 1999). Although BjHMGS1 to BjHMGS4 are highly-conserved, they are differentially expressed during floral and seedling development (Nagegowda et al., 2005). BjHMGS1 was localized in the cytosol by confocal microscopy and western blot analysis of subcellular protein fractions from transgenic plants expressing Green Fluorescent Protein-tagged BjHMGS1 (Nagegowda et al., 2005). The structure of BjHMGS1 in molecular interaction with its inhibitor F-244 has been elucidated to explore the potential of using HMGS as an alternative target for anti-cholesterol and antibiotic drugs, given that MVA is a precursor of cholesterol in mammals and HMGS inhibition adversely affects bacterial viability (Pojer et al., 2006). We first report on the biochemical characterization of a plant-derived HMGS using bacterial-expressed recombinant (His)6-tagged BjHMGS1 (Nagegowda et al., 2004). Catalytic residues in BjHMGS1 were identified by site-directed mutagenesis (Nagegowda et al., 2004). (His)6-BjHMGS1 was inhibited by one of the substrates (AcAc-CoA) and by both products (HMG-CoA and HS-CoA). Site-directed mutagenesis of conserved amino acid residues in BjHMGS1 revealed tha t substitutions R157A, H188N and C212S resulted in a decreased Vmax, indicating some involvement of these residues in catalytic capacity. Unlike (His)6-BjHMGS1, the H188N mutant did not display substrate inhibition by AcAc-CoA. Substitution S359A resulted in a 10-fold increased specific activity. Subsequently, we generated a novel double mutation H188N/S359A, which resulted in a 10-fold increased specific activity, but still lacking inhibition by AcAc-CoA, strongly suggesting that H188 is involved in conferring substrate inhibitio n to (His)6-BjHMGS1 (Nagegowda et al., 2004). The identification of BjHMGS1 mutants which are substrate insensitive and show enhanced enzymatic activity (Nagegowda et al., 2004) provides us the tools for the metabolic engineering of isoprenoids. Investigations on the over expression of these mutant BjHMGS1 in model plants is a first step towards this end. Specifically, this project will investigate the effects in the overexpression of wild-type and mutant (H188N, S359A and H188N/S359A) BjHMGS1 in model plants, Arabidopsis and tobacco. The following problems will be addressed: 1. Does the overexpression of wild-type or mutant BjHMGS1 improve isoprenoid accumulation in model plants and if it does, what is the identity of the isoprenoid compounds that accumulate? 2. Which version (wild-type/mutant) of BjHMGS1 is most effective in causing isoprenoid accumulation when overexpressed in transgenic plants? 3. Does the overexpression of wild-type/mutant BjHMGS1 affect plant growth, development and defense against phytopathogens? To examine isoprenoid accumulation, isoprenoid products such as the various plant sterols (campesterol, sitosterol and stigmasterol) and sesquiterpenes will be measured in transgenic Arabidopsis and tobacco lines. Plant sterols will be measured because they are useful as functional foods as they can block intestinal cholesterol adsorption and lower cholesterol in humans (Ostlund et al., 2003). Sitosterol further promotes plant growth and development while sesquiterpenes enhance plant defense. Transgenic Arabidopsis and tobacco will also be examined for changes in growth using germinating seedlings, and for any improved disease resistance to Botrytis cinerea (fungal pathogen). These proposed investigations using model plants are prerequisite to the application of wild-type/mutant BjHMGS1 in tra nsgenic Artemisia which produces artemisinin (a sesquiterpene) via the MVA pathway or in crops for improved growth and protection against phytopathogens, as well as for the production of sterol-enriched plant products in functional foods to control cholesterol adsoprtion. References: 5-year IF(2008):PNAS 10.228;Plant J 6.951;Plant Physiol 6.650;Biochem J 4.251;Plant Mol Biol 3.901;Planta 3.304 1. Alex D, Bach TJ, Chye ML (2000) Plant J 22:415-426. 2. Bach TJ (1995) Lipids 30:191-202. 3. Chye ML, Tan CT, Chua NH (1992) Plant Mol Biol 19: 473-484. 4. Dhawan R et al. (2009) Plant Cell 21:1000–1019. 5. Ferrari S et al. (2003) Plant J 35:193-205. 6. Hemmerlin A, Bach TJ (1998) Plant J 14:65-74. 7. Hemmerlin A et al., (1999) Acta Bot Gall 146:85-100 8. Kush A, Goyvaerts E, Chye ML, Chua NH (1990) Proc Natl Acad Sci USA 87:1787- 1790. 9. Lichtenthaler HK (1999) Annu Rev Plant Physiol Plant Mol Biol 50:47-65. 10. Nagegowda DA, Bach TJ, Chye ML (2004) Biochem J 383:517-527. 11. Nagegowda DA, Ramalingam SK, Hemmerlin A, Bach TJ, Chye ML (2005) Planta 221:844-856. 12. Ostund RE et al. (2003) American J Clin Nutr 77:1385-1389. 13. Pichersky E, Gershenzon J (2002) Curr. Opin. Plant Biol. 5: 237-243. 14. Pojer F, Ferrer JL, Richard SB, Nagegowda DA, Chye ML, Bach TJ, Noel JP (2006) Proc Natl Acad Sci USA 103:11491-11496. 15. Roberts SC (2007) Nature Chemical Biology 3: 387-395. 16. Rohmer M (1999) Nat Prod Rep. 16:565-574. 17. Schaller H, Grausem B, Benveniste P, Chye ML, Tan CT, Song YH, Chua NH (1995) Plant Physiol 109:761- 770.


List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Arabidopsis acyl-Coenzyme A-binding proteins, American Oil Chemists Society (AOCS) Lipid Library, Plant Lipid Biochemistry . 2010.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Chye M.L. , Editorial Advisory Board, The Open Plant Science Journal (Bentham Science Publishers) . 2010.
Chye M.L. , Editorial Board, Botanical Studies (Institute of Plant and Microbi al Biology, Academia Sinica) . 2010.
Chye M.L. , Editorial Board, Journal of Botany (Hindawi Press) . 2010.
Chye M.L. and Zhao K.J., Genetically modified plants with enhanced resistance to fungal disease and a method of production thereof, Chinese Patent ZL02822987.8 issued Oct 14, 2009 . 2009.
Chye M.L. , Member (Editor), Planta Editorial Board, Planta, Springer-Verlag GmbH . 2009.
Chye M.L. , Member, Editorial Advisory Board, The Open Plant Science Journal, Bentham Science Publishers . 2009.
Chye M.L. , Member, Editorial Board, Botanical Studies (Institute of Plant and Microbial Biology, Academia Sinica) . 2009.
Chye M.L. , Member, Editorial Board, Journal of Botany (Hindawi Press) . 2009.
Chye M.L. , Planta Editorial Board, Planta (Springer-Verlag) . 2010.
Chye M.L. , Tolerant to cold snaps, HKU Pavilion, InnoCarnival, Innovation Festival, Science Park. 2009, 5th - 8th Nov, 2009 .
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Ubhayasekera W., Rawat R., Ho S.W.T. , Wiweger M., Von Arnold S., Chye M.L. and Mowbray S., The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce, Plant Molecular Biology . 2009, 71: 277-289.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidylcholine and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Resear ch, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Corke H

Project Title: 2nd International Wheat Quality Conference Effect of Wheat Quality on Noodle Production
Investigator(s): Corke H
Department: Botany
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2001
Abstract:
N/A


Project Title: Molecular markers for starch content and quality in rice
Investigator(s): Corke H
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 11/2006
Completion Date: 10/2009
Abstract:
To develop gene-tagged markers and their integration into a genetic linkage map, and mapping OTL for starch content and quality (structural and functional properties); to sequence major genes, analysis of gene diversity and linkage disequilibrium, and association mapping of the genes in relation to starch content and quality; to develop a protocol for marker-assisted selection to most effectively simulate multiple components contributing to high starch contents and desired starch properties in Chinese rice breeding and therefore with direct applicability to economic development in China.


Project Title: ASA-CSSA-SSSA International Annual Meetings 2009 Molecular markers for starch quality of rice
Investigator(s): Corke H
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 11/2009
Completion Date: 11/2009
Abstract:
N/A


List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food : Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Cai Y. , Ke J.X. and Corke H. , MALDI-QIT-TOF MS determination of proanthocyanidins in crude extracts of selected dietary plants and medi cinal herbs (Abstract), Global Chinese Health (Functional) Food Symposium 2009 (Hong Kong) . 2009.
Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Xiong G.Q., Cheng W., Ye L.X., Du X., Zhou M., Lin R.T., Geng S.G., Chen M.G., Corke H. and Cai Y. , Effects of konjac glucomannan on physicochemical properties of myofibrillar protein and surimi gels from grass carp ( Ctenopharyngodon idella ), Food Chemistry . 2009, 116 (2): 413-418.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/gluco se model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Du Y

List of Research Outputs

Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-induci ble flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Du Y. and Lo C.S.C. , Molecular characterizatiom of a flavone synthase gen e in sorghum, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deo xyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Micr obe Interactions . 2009.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.


Researcher : Du Z

List of Research Outputs

Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.


Researcher : Dudgeon D

Project Title: The conservation of freshwaters in tropical Asia
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 01/2002
Abstract:
To write a book setting out the conservation status of lake and river ecosystems in the oriental tropics, for publication by Backhuys Press in 2004.


Project Title: The ecology and biodiversity of Hong Kong
Investigator(s): Dudgeon D, Corlett RT
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 07/2002
Abstract:
To produce a revised edition of Dudgeon and Corlett (1994) "Hills and streams: an ecology of Hong Kong" for simultaneous publication in Chinese nd English.


Project Title: Tropical stream ecology
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 01/2003
Abstract:
To produce a multi-authored volume focused on comparison of streams among tropical regions on a topic-by-topic basis; to summarise what is known by highlighting similariti es among regions (particularly the ecological responses to a climatic backdrop of wet versus dry seasons, plus temperature close to the biological optimum), and to account for any consistent patterns of difference that emerge; to highlight what we do not know, and suggest ways of filling these knowledge gaps in a subsection of each chapter entitled 'future research directions and information needs'.


Project Title: Conservation of freshwater biodi versity in Asia
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 06/2003
Abstract:
To write a book for discussing the issues and implications of damages and pollution causes by human beings.


Project Title: Scale-specific inter-population variation in the proteomics of Caridina shrimps in Hong Kong
Investigator(s): Dudgeon D, Chan LL
Department: Ecology & Biodiversity
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To understand whether molecular differences revealed by RAPD are adaptations to local conditions, or merely a reflection of non-adaptive variation, we must stud y what proteins are actually present in each population.


Project Title: Biodiversity and ecosystem functioning in Hong Kong streams
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
To establish the functional role of invertebrates associated with leaf litter; to test the relationship between shredder diverstiy and detritus processing rates along a gradient of stream characteristics; to determine the relationship between leaf quality, shredder diversity and detritus processing rates; field studie s to determine the effects of changed flow regimes on shredder diversity and detritus processing rates; to use artificial stream channels to determine the effects of shredder diversity, changed flow regimes and water temperature on detritus processing rates; to establishment of the relationship between shredder diversity and detritus processing rates using field microcosms and laboratory experiments.


List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.
Dudgeon D. , Associate Editor, Hydrobiologia (2002-present), 2009.
Dudgeon D. , Associate Editor, Aquatic Sciences . 2010.
Dudgeon D. , Associate Editor, Hydrobiologia . 2009.
Dudgeon D. , Editorial Board, Aquatic Conservation: Marine and Freshwater Ecosystems . 2009.
Dudgeon D. , Editorial Board, Freshwater Biology . 2009.
Dudgeon D. , Editorial Board, River Research and Applications . 2009.
Dudgeon D. , Mantel S...K... and Cheung K.W. , Food-web structure in small streams: do we need different models for the tropics?, Journal of the North American Benthological Society . 2010, 29: 395-412.
Dudgeon D. , Freshwater Biodiversity in the Anthropocene , DIVERSITAS OCS2: Biodiversity and Society – Understan ding Connections, Adapting to Change 2009 (Capetown, South Africa) . 2009.
Dudgeon D. , Member, Editorial Board of Aquatic Conservation: Marine and Freshwater Ecosystems (1998-present), 2009.
Dudgeon D. , Member, Editorial Board of Freshwater Biology (2007-present), 2009.
Dudgeon D. , Member, Editorial Board of Freshwater Biology (2007-present), 2009.
Dudgeon D. , Member, Editorial Panel of River Research and Applications (formerly Regulated Rivers: Research and Management) (1994-present), 2009.
Dudgeon D. , Requiem for a river: extinctions, climate change and the last of the Yangtze., Aquatic Conservation: Marine and Freshwater Ecosystems . 2010, 20: 127-131.
Dudgeon D. , Subject Editor, Biotropica (2001-2007), 2009.
Dudgeon D. , Tropical Asian Rivers in times of change, 10th International Congress of Ecology (INTECOL) 2009 (Brisbane, Australia) - invited but unable to attend. . 2009.
Dudgeon D. , • SIL Symposium on Global Change and Freshwater Environments 2009 (Nanjing, China): Into the Anthropocene: freshwater biodiversity in China – plenary lecture., 2009.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predator on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Annual Meeting of the Society for Conservation Bio logy . 2009.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Joint Annual Meeting of Ichthyologists and Herpeto logists . 2009.
Kwong K.L., Dudgeon D. , Wong P.K. and Qiu J.-.W., High secondary production and diet of an invasive snail in freshwater wetlands: implications for resource co nsumption and competition. , Biological Invasions . 2010, 12: 1153-1164.
Naiman R...J... and Dudgeon D. , Global alteration of freshwaters and influences on human and environmental well-being., Ecological Research . 2010, 25: DOI 10.1007/s11284-010-0693-3.
Strayer D. and Dudgeon D. , Freshwater biodiversity conservation: recent progress and future challenges., Journal of the North American Benthological Society . 2010, 29: 344-358.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Yang Y. and Dudgeon D. , Dietary variation and food selection by an algivorous loach (Pseudogastromyzon myersi: Balitoridae) in Hong Kong streams., Marine and Freshwater Research . 2010, 61: 49-56.
Yang Y. and Dudgeon D. , Response of grazing impacts of an algivorous fish (Pseudogastromyzo n myersi: Balitoridae) to seasonal disturbance in Hong Kong streams. , Freshwater Biology . 2010, 55: 411-423.
Yang Y. and Dudgeon D. , Spatial and seasonal variations in benthic algal assemblages in streams in monsoonal Hong Kong., Hydrobiologia . 2009, 632: 189-200.
Zhang Y. and Dudgeon D. , Impacts of deforestation and hydrological change on river ecosystems in Southeast Asia. , In: L. Lebel, A. Snidvongs, C.-T. A. Chen & R. Daniel, Critical States: Environmental Challenges to Development in Monsoonal Southeast Asia . Petaling Jaya, Malaysia, , Strategic Information and Research Development Centre, 2009, 268-280.


Researcher : Dumont C

Project Title: Functional importance of sea urchins and coral-feeding invertebrates on bioerosion of corals
Investigator(s): Dumont C
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Completion Date: 09/2010
Abstract:
Over the last decades, coral reef ecosystems have undergone widespread declines due to storms, predation, bleaching, disease and anthropogenic disturbances (Hughes et al. 2003, Pandolfi et al. 2003, Mora et al. 2006, Mumby et al. 2006, De'ath et al. 2009). Direct consumption of live coral, or corallivory, represents a biotic stressor that can adversely affect coral fitness and accelerate rates of coral decline (Rotjan et al. 2006). In addition to being coral predators, some corallivores and others grazers (e.g. sea urchins) may also act as bioeroders (consumers of dead coral substrate) which are known to play an important role in coral reef dynamics by eroding skeletons of corals, yet little attention has been paid to the diverse roles corallivores and grazers might play in maintaining a complex of interactions influencing the structure of corals reef communities. The corallivorous gastropods Drupella spp. and the crown-of-thorns seastar Acanthaster planci are known as agents of large-scale disturbance to coral reefs (Turner 1994, Carpenter 1997). Population outbreaks have been reported at various Indo-West Pacific location s (e.g. Malaysia, Hong Kong and Japan) and a number of studies correlate the high density of these corallivores with a drastic reduction in coral cover (reviewed by Endean & Cameron 1990). The suggested causative factors responsible for these outbreaks are numerous and include over-fishing, pesticide use, atomic testing, rain fore st depletion, global climate change, and over-population (Endean & Cameron 1990, Sapp 1999). Regardless of the cause, Drupella and Acanthaster feed on live coral tissue, leaving white feeding scars and aggregations often cause as much as 95% coral mortality in a localized area (Carpenter 1997). Facultative corallivores, both the sea star A. planci and the snails Drupella spp. preferentially consume live tissues of Montipora and Acropora corals but avoid feeding on only few sclerac tinian species (Morton & Blackmore 2000, Pratchett 2007). Numerous experimental studies based on the exclusion of herbivores from areas of reefs have demonstrated the importance of macroherbivores on patterns of algal communities. On a large scale, the effects of removal of the herbivore sea urchin Diadema antillarum in the Carribbean with the spread of a disease has further highlighted the importance of the role that sea urchins play in controlling algal communities and in maintaining an healthy balance between corals and algae (Lessios 1988, Edmunds & Carpenter 2001). On the other hand, sea urchins, and especially diadematids, are considered to also act as bioeroders, playing an important role in coral reef dynamics (Bak 1990, 1994, Carreiro-Silva & McClanahan 2001). While grazing on algae growing on dead corals, sea urchins also remove calcium carbonate with its very powerful jaw apparatus which may weaken the structure of cora l colonies but it remains unclear whether Diadema readily consumes live corals (i.e. facultative corallivorous). Considering that sea urchins can act as an herbivore and bioeroder, the role of sea urchins in reef trophodynamics is probably more complex than appreciated previously. The functional role of sea urchins in coral decline is controversial, having an important role in preventing alga overgrowth on corals and on the other hand the bioerosion of corals while grazing. A manipulative experiment in French Polynesia revealed that an increase of the density of the sea urchin Echinometra mathaei reduced the algae cover on the coral Acropora pulchra but also increase its bioerosion (Mapstone et al. 2007). More interestingly, the removal of sea urchins resulted to a similar algae cover than the treatment with natural urchin densities but an increase in coral mortality occured. It remains unclear the reasons of this increase of coral mortality but the authors suggest that the reduction of grazing pressure by urchins may have been responsible to an increase of boring invertebrates on dead corals that are normally removed by urchin grazing. Thus, we could hypothesize that urchins may primarily graze on fouling growing on dead corals pr eviously preyed by corallivorous (i.e. Drupella spp., Acanthaster planci), yet no studies examined the corallivore-herbivore-cor al interactions. The present study will address these gaps in our understanding by focusing on the functional role of these coral-feeding invertebrates (Drupella spp. and Acanthaster planci), and the grazing impact of the sea urchin Diadema setosum on bioerosion of coral reefs. In particular, we address the following questions: (1) What is the functional role of sea urchins and coral-feeding invertebrates on coral reefs? (2) Do corallivorous invertebrates facilitate bioerosion of corals by sea urchins? (3) How important is the grazing impact of sea urchins in the bioerosion of coral reefs? (4) What are the consequences of an abrupt decrease (manually removal) of coral-feeding predators (Drupella spp. in Hong Kong and Acanthaster planci in Malaysia) and Diadema setosum population? The answers to these questions will help understanding which functional role sea urchins and corallivorous gastropods have on coral reefs. The ability to understand the role and relative importance of the herbivorous and coralivorous invertebrates requires an understandin g of the quantitative impact of each species, their respective roles and interactions. We won’t be able to answer all the questions mentioned within this short-term proposal but the aim of the present study is to explore the interaction of coral invertebrate predators and grazers in the bioerosion of coral reefs and bring preliminary data to further explore hypotheses and write a strong proposal for further funding. We will therefore conduct our study with the following objectives : (1) Determine abundance and distribution of the herbivore Diadema setosum and corallivorous invertebrates on coral reefs (2) Examine the diet of the sea urchin Diadema setosum and the gastropods Drupella spp. and Cronia margariticola on coral reefs (3) Quantify the impact of corallivorous invertebrates and sea urchins on bioerosion of coral reefs.


Project Title: Mechanisms maintaining the coexistence of sea urchins in a seasonal subtropical rocky habitat
Investigator(s): Dumont C, Wai TC, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2009
Abstract:
1) To determine intra-and inter-specific variation in niche partitioning of the sea urchins Anthocidaris crassispina and Diadema setosum; 2) To examine the effect of fishing pressure on niche partitioning of the sea urchins Anthocidaris crassispina and Diadema setosum; 3) To examine the competitive ability of the urchin species and their interactions under shared predation.


List of Research Outputs

Dumont C. and Alfian K., Corals at risk: Effectiveness of the removal of a keystone coral-predator Acanthaster planci in a marine park of Malaysia. , 2nd Asia Pacific Coral Reef Symposium . 2010.
Dumont C. , Resistance of marine communities to human-facilitated invasion, Banyuls Marine Observatory, France . 2010.
Thiel M., Chak S.T.C. and Dumont C. , Mating behavior of the dancing shrimp Rhynchocinetes brucei (Decapoda: Caridea), Journal of Crustacean Biology . 2010, 33: 580-588.


Researcher : Dvornyk V

Project Title: Microevolution of circadian genes in cyanobacteria under long-term natural stress
Investigator(s): Dvornyk V
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2008
Completion Date: 09/2010
Abstract:
The overall objective of the proposed project is to study microevolution of the circadian clock system in cyanobacteria experiencing long-term complex natural stress and to determine factors having contributed to this evolution. This proposal encompasses the approaches of molecular genetics, genomics, and evolution and efficiently utilizes PI’s expertise in these fields. The hypothesis is: Microevolution of the circadian clock system in cyanobacteria under acute natural stress is primarily adaptive. The major goals are to determine: 1. Intra- and interslope polymorphisms in the studied genes. This will shed light on probable evolutionary forces that shape these polymorphisms under stress. 2. Intra- and interpopulation polymorphisms in the studied genes. This will help to distinguish population-specific adaptations from those common for the populations from both ECs. 3. Polymorphism in the previously identified functional domains of the genes under study. Accomplishment of this goal will help to identify functional significance of the domains (regions) in adaptation of cyanobacteria to complex natural stress. To reach the goals, the following specific aims will be fulfilled: 1. Sequencing 7 of the currently known circadian genes from 80 strains of N. linckia sampled on the opposite slopes of both ECs. To sequence partially the 16S rRNA genes from the same strains for the comparative evolutionary analysis. 2. Conducting a comprehensive evolutionary analysis of the sequenced genes and to estimate contribution of various evolutionary factors to the observed pattern s of nucleotide polymorphism. A major advantage of this proposal is that it is a natural extension of and based upon the PI’s previous highly productive and successful work and outstanding expertise in evolution of the circadian system in prokaryotes.


Project Title: 12th Congress of the European Society for Evolutionary Biology Building-up the Cyanobacterial Circadian Clock: An Evolutionary Perspective
Investigator(s): Dvornyk V
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Evolution of cryptochromes in fish
Investigator(s): Dvornyk V, Sadovy YJ
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
The overall objective of the proposed project is to study evolution of cryptochromes, a family of important circadian genes, in fish and to determine factors having contributed to this evolution. This proposal encompasses the approaches of molecular genetics, genomics, evolut ion, taxonomy, and ecology, and efficiently utilizes PI’s and co-I’s expertise in these fields. The major goals are: 1. Determine patterns of nucleotide and amino acid diversity in the cryptochromes. This will shed light on probable evolutionary forces that shaped this diversity. 2. Reconstruct a comprehensive phylogeny of the genes. 3. Estimate functional divergence between the paralogous members of the cryptochrome gene family. 4. Estimate functional divergence between the orthologous members of the cryptochrome gene family. This will help to identify putative amino acid residues, which are funct ionally important. 5. Determine reliably a timeline of the key events in the genes’ evolution (e.g., gene duplications, etc.). 6. Establish a basis for the future comprehensive evolutionary studies of circadian genes in eukaryotes. To reach the goals, the following specific aims will be fulfilled: 1. Sequence partially eight known fish cryptochromes from 20 fish species representing major taxonomic units and contrasting ecological habitats. 2. Conduct a comprehensive evolutionary analysis of the sequenced genes and to estimate contribution of various evolutionary factors to the observed patterns of nucleotide diversity. A major advantage of this proposal is that it is a natur al extension of and based upon the PI’s previous highly productive and successful work and outstanding expertise in evolution of the circadian system in prokaryotes.


List of Research Outputs

Baca I., Sprockett D. and Dvornyk V. , Circadian input kinases and their homologs in cyanobacteria: Evolutionary constraints versus architectural diversification, Journal of Molecular Evolution . New York, Springer, 2010, 70: 453-465.
Dvornyk V. , Building-up the Cyanobacterial Circadian Clock: An Evolutionary Perspective, 12th Congress of European Society for Evolutionary Biology . Turin, Italy, 2009.
Dvornyk V. , Editorial Board, International Journal on Algae . New York, Begell House, Inc., 2010.
Liu P.Y., Lu Y., Recker R.R., Deng H.W. and Dvornyk V. , ALOX12 gene is associated with the onset of natural menopause in white women, Menopause . LWW, 2010, 17: 152-156.
Liu P.Y., Lu Y., Recker R.R., Deng H.W. and Dvornyk V. , Association analyses suggest multiple interaction effects of the methylenetetrahydrofolate reductase polymorphis ms on timing of menarche and natural menopause in whites, Menopause . LWW, 2010, 17: 185-190.


Researcher : El-Nezamy HS

Project Title: An in vitro model to predict the bioactivity of food ingredients
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 02/2008
Completion Date: 01/2010
Abstract:
Development of future foods is based on detailed knowledge of their biological effects. To gain this knowledge appropriate models that simulate the transpor t and biotransformation of foods and food ingredients in the gastrointestinal tract are needed. Understanding of their metabolism and transport is of critical importance in assessment of both harmful and beneficial effects of these compounds and their interactions with other dietary components. Biotransformation reactions in the liver, intestine and intestinal microbiota differ in that the CYP-mediated oxidative reactions in liver and intestinal cells need oxygen, but most of the intestinal microbes are strictly anaerobic. Consequently, the aim of this project is to develop an in vitro based biochamber model that allows the simultaneous culturing of eukaryotic and prokaryotic cells for studying gastrointe stinal metabolism of food ingredients and their interactions with other dietary components. The key players in the gastrointestinal biotransformations - enterocytes, hepatocytes, colonocytes and intestinal microbiota – are cultured in compartments associated with semi-permeable membranes. To test the feasibility of this chamber, the metabolism of a model compound will be determine d. The model compound to be studied is aflatoxin B1 (AFB1), a liver carcinogen with known metabolic pathways in the body.


Project Title: Combined effects of mycotoxins on the intestinal local immune responses.
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2008
Completion Date: 11/2009
Abstract:
Despite the fact that there are 1000's of original research publications available on the potential toxicity and carcinogenicity of mycotoxins, we have identified several gaps in the literature, particularly in relation to the immunotoxicity of mycotoxins and the proposed project will address a number key issues in this area. Key Issue 1: Interactive effects of mycotoxins. Mycotoxins are a chemically diverse group of compounds. Typically, it is common to detect several types of mycotoxins in the same crop, while it is rare to find a crop which is contaminated with only a single mycotoxin. Data on the immunotoxicity of commonly occurring mixtures of toxins are absent. Key Issue 2: Mycotoxins-induced immunotoxicity on local intestinal immune responses. The intestinal epithelia are the first barrier restricting the entry of foreign antigens and dietary toxins, including mycotoxins, into the underlying tissues. Despite this, the majority of published research on mycotoxins-induced immunotoxicity focuses on their impact on systemic immunity rather than local immunity. Consequently, the specific aim of this pilot project is to evaluate the individual and combined effects of mycotoxins on the intestinal local immune responses, we will study the interactive effects of single, binary and tertiary mixtures of mycotoxins, deoxynivalenol (DON), fumonisin B1 (FB1) and aflatoxin B1 (AFB1), using the human ad enocarcinoma cell line (Caco-2). The end points will include inhibition of cell proliferation and expression of mRNA encoding for pro-inflammatory cytokines (including IL-1β, IL-6 , IL-8, IL-12, IFN-γ and TNF-β). This study will provide useful information on whether these mycotoxins have additive or synergistic immunotoxicity in these epithelial cells.


Project Title: The melamine milk - kidney and developmental toxicity: impact on the foetus and the disease development later in life
Investigator(s): El-Nezamy HS, Chen Y, Tam PKH, Lau ASY, Chen SF, Leung FCC, Lan LCL, Wang M
Department: School of Biological Sciences
Source(s) of Funding: Studies Related to Melamine Incident
Start Date: 04/2009
Abstract:
To evaluate the toxic effects of melamine milk on renal inflammation and kidney stone formation in mice; to evaluate the maternal foetal transplacental passage using ex vivo human placenta model; to investigate in an animal model the short and long term implications of exposure to melamine and its degradation products in utero and during early stages of life.


Project Title: 7th Congress of Toxicology in Developin g Countries Biomarker survey of aflatoxin and deoxynivalenol exposure in pregnant Egyptian women
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 09/2009
Completion Date: 09/2009
Abstract:
N/A


List of Research Outputs

El-Nezamy H.S. , Associate Editor, Frontiers in Pharamcology / Frontiers in Predictive Toxicity . 2010.
Gratz S.W., Mykkanen H. and El-Nezamy H.S. , Probiotics And Gut Health : A Special Focus On Liver Disease, World Journal of Gastroenterology . 2010, 16: 403-410.
Partanen H.A. , El-Nezamy H.S. , Leppanen J.M., Woodhouse H.J. and Vahakangas K.H., Aflatoxin B1 Transfer And Metabolism In Human Placenta, Toxicological Sciences . 2010, 113: 216-225.
Salminen S., Nybom S., Meriluoto J., Collado M., Vesterlund S. and El-Nezamy H.S. , Probiotic Pathogen/toxin Interaction - Benefits To Human Health And Nutrition, Current Opinion in Biotechnology . 2010, 21: 157-167.


Researcher : Faan YW

List of Research Outputs

Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.


Researcher : Fan KW

List of Research Outputs

Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Gao W

List of Research Outputs

Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Gao W

List of Research Outputs

Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Gu JD

Project Title: Super genetic engineered bacterium and detoxification enzymes for bioremidiation
Investigator(s): Gu JD
Department: Ecology & Biodiversity
Source(s) of Funding: Matching Fund for Hi-Tech Research and Development Program of China (863 Projects)
Start Date: 02/2004
Abstract:
To study super genetic engineered bacterium and detoxification enzymes for bioremidiation.


Project Title: Uncovering proteins associated with toxin biosynthesis in dinoflagellates by proteomic approaches
Investigator(s): Gu JD, Chan LL
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2007
Abstract:
(1) Identification of“STX-related proteins (SRPs)” by comparing the differential protein expression patterns of phylogenetically closely related toxic and non-toxic strains of A. tamarense by 2-D DIGE under different growth conditions and toxin production; (2) Identification of common “toxic-specific proteins” between phylogenetic ally distant STX-producers in different genera by 2-D DIGE; (3) Characterization of these candidate proteins by trypsin in-gel digestion coupled with matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) by bioinformatic mining for homologues or de novo sequencing by Edman protein sequencing and nanospray tandem mass spectrometry (MS/MS).


Project Title: 110th General Meeting of the American Society for Microbiology Quantitative Detection of Ammonia-oxidizing Archaea (AOA) and Ammonia-oxidizing Bacteria (AOB) in Mangrove Sediment
Investigator(s): Gu JD
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2010
Completion Date: 05/2010
Abstract:
N/A


List of Research Outputs

Han X. and Gu J.D. , Sorption and transformation of toxic metals by microorg anisms, In: R. Mitchell, J.-D. Gu, Environmental Microbiology (2nd ed.) . Hoboken, New Jersey, Wiley-Blackwell, 2010, 153-176.
Hong Y. and Gu J.D. , Bacterial anaerobic respiration and electron transfer relevant to the biotransformation of pollutants, International Biodeterioration & Biodegradation . New York, Elsiver, 2009, 63: 973-980.
Li M. , Hong Y., Klotz M. and Gu J.D. , A comparison of primer sets for detecting 16S rRNA and hydrazine oxidoreductase genes of anaerobic ammonium-oxidizing bacteria in marine sediments, Applied Microbiology and Biotechnology . Heidelberg, Germany, Springer, 2010, 86: 781-790.
Li M. , Yang H. and Gu J.D. , Phylogenetic diversity and axial distribution of microbes in the intestinal tract of the polychaete Neanthes glandicincta, Microbial Ecology . New York, Springer, 2009, 58: 892-902.
Mitchell R. and Gu J.D. , Environmental Microbiology (2nd ed.) . Hoboken, New Jersey, Wiley-Blackwell, 2010, 363.
Yu X. and Gu J.D. , Effect of temperature on removal of iron cyanides from solution by maize plants, Environmental Science and Pollution Research . Berlin / Heidelberg, Springer, 2010, 17: 106-114.
Zhang R. and Gu J.D. , Complete sequence of plasmid pMP1 from the marine environment al Vibrio vulnificus and location of its replication origin, Marine Biotechnology . New York, Springer, 2009, 11: 465-462.
Zhao Z.Y., Gu J.D. , Li H.B., Li X.Y. and Leung K.M.Y. , Disinfection characteristics of the dissolved organic fractions at several stages of a conventional drinking water treatment plant in Southern China, Joural of Hazardous Materials . 2009, 172: 1093-1099.


Researcher : Ho CWJ

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.


Researcher : Ho KY

List of Research Outputs

Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Ho SWT

List of Research Outputs

Ubhayasekera W., Rawat R., Ho S.W.T. , Wiweger M., Von Arnold S., Chye M.L. and Mowbray S., The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce, Plant Molecular Biology . 2009, 71: 277-289.


Researcher : Hon CC

List of Research Outputs

Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Huang W

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.


Researcher : Huang W

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.


Researcher : Hui RKH

Project Title: 2009 Conference of Research Workers in Animal Diseases Effects of Nsp2 Deletions on PRRSV Genome and Replication Efficiency
Investigator(s): Hui RKH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 12/2009
Completion Date: 12/2009
Abstract:
N/A


List of Research Outputs

Hui R.K.H. , Wang K.X. and Leung F.C.C. , Effects Of Nsp2 Deletions On PRRSV Genome And Replic atoin Efficiency., International PRRS Symposium 2009, National Pork Board . 2009.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographi c dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Sympos ium . 2009.


Researcher : Hyde KD

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.


Researcher : Ip KM

List of Research Outputs

Ip K.M. and Wong A.S.T. , p70 S6 kinase regulates the actin cytoskeleton in ovarian cancer cell motility by binding and cross-linking actin filaments, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5116) . 2010.


Researcher : Jiang J

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposi um . 2009.


Researcher : Jiang P

List of Research Outputs

Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Jiang Q

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeti ng of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Jor WY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Jor WY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Karczmarski L

Project Title: Population ecology of Indo-Pacific humpback dolphins. Phase 1: Establishing baseline models and comparative approach
Investigator(s): Karczmarski L
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Background of Research Indo-Pacific humpback dolphins (Sousa chinensis) occur in coastal waters of Indian and western Pacific oceans, from South Africa in the west to southeast China in the east (Jefferson & Karczmar ski 2001). The population that inhabits the Pearl River Estuary (PRE) has become the focus of international interest due to its proximity to the world’s busiest port and fast developing economy. This dolphin population has been studied since the early 1990’s with a primary focus on estimating abundance, distribution, and conservat ion status (e.g. Jefferson 2000, Jefferson & Hung 2004, Hung & Jefferson 2004). Despite these commendable efforts, this earlier work was restricted almost exclusively on Hong Kong waters and due to methodological limitations did not achieve more in-depth population level analyses. Consequently, much of the population parameters, structure, and socio-ecological dynamics remain poorly known. Genetic studies are very recent and limited, although preliminary data (Chen et al. 2008) suggests low mtDNA diversity; which is surprising in the context of the apparently large population size (believed to be circa 1500 individuals; Jefferson & Hung 2004). This contrad ictions (apparent population size vs. within-population genetic diversity) require further investigations. There has been very little cetacean research elsewhere in the Southeast Asian region and by comparison, despite various limitations, the dolphin population that inhabits PRE is better understood than many other populations of the genus Sousa and all other cetacean populations in Southeast Asia. With the data accumulated over the past years and with recent advances in modern analytical techniques, there is currently a good base and means for examining in greater detail the population ecology and structure, and establishing a broader comparative approach across species and populations in the region. The time is also right for a hypothesis-driven resear ch that would investigate socio-behavioural dynamics of humpback dolphins in a broader context of mammalian behavioural ecology. Objectives This project represents an initial phase of a larger-scale undertaking that is intended for GRF grant support; it addresses a range of topics, from establishing initial quantitative dataset for the 'Primary Objectives' to facilitating 'Broader Comparative Perspective' through collaborative research. To achieve these objectives, the study will go beyond the time-frame of this Seed Funding; all the topics listed below will be explored further under GRF grant application and other funding scheme, but the current project represents a critical first step. Primary Objectives Population Parameters – perform mark-recapture analyses of the humpback dolphin population in the Pearl River estuary; model the population structure, quantify immigration/emigration rates and patterns of geographic fidelity Movement, Ranging Pattern and Individual Range Use – quantify spatial and temporal movement patterns of individuals, including rate of population spread (diffusion) and the displacement of individuals over time Socio-Behavioural Dynamics – quantify groups structure, model individual residence rates and inter- and intra-group social dynamics relative to age and sex, and intra- and inter-sexual relationsh ips within and between groups Genetic Structure and Population Connectivity – quantify and model population genetic structure, assess dispersal pattern, and provide initial basis for broader analysis of population connectivity on a local and regional scale Broader Comparative Perspective Comparative Socio-Ecology – establish a comparative, collaborative research which, with a similar framework of quantitative analytical procedu res, would facilitate constructing a broader model system of a coastal delphinid with the humpback dolphin as a focus species Hypothesis and Analytical Framework A recently proposed socio-ecological model (Gowans et al. 2008) suggests that spatial and temporal predictability of resources, habitat structure, predator pressure, and in some cases availability of mates determine the structure of local populations and their socio-behavioural strategies. According to this model, species inhabiting complex inshore and estuarine systems, where resources are spatially and temporally predictable, are likely to remain resident in relatively small areas. Contrary to wide-ranging large groups of pelagic dolphins, in these diverse inshore environments dolphins can either hide from predators or avoid areas with high predator density. With limited food resources, there are few benefits to forming large groups and potentially many benefits to being solitary or in small groups; while males may be able to sequester solitary females, controlling mating opportunities. However, in open coastal habitat s with variable resources, or in environments substantially altered by human activities, dolphins are likely to display an intermediate-ranging pattern due to less predictable or depleted resources, with some site fidelity over relatively large ranges. At intermediate ranging, dolphins form intermediate-sized groups that are gener ally highly dynamic with little temporal stability, which reduces intra-group scramble competition while still providing protection against predators. This pattern is likely to prevent the formation of long-term complex bonds and might affect male mating strategies. Photographic identification data have shown this model to hold tr ue for humpback dolphins in the coastal environment of South Africa. We suggest that humpback dolphins in the coastal region of the Pearl River Estuary will exhibit similar pattern of dispersal and group formation as humpback dolphins off South Africa (Karczmarski 1999, Karczmarski et al. 1999, 2000, Karczmarski & Guissamulo Under Review) due to comparable environmental pressures. We will test our hypotheses using photographic identification techniques (which will be supported further, in a follow-up study under GRF grant support , by genetic techniques). Through photo-identification mark-recapture analyses, we will examine and quantify the level of geographic fidelity of humpback dolphins using lagged identification rates. We anticipate the dolphins to exhibit weak site fidelity to specific locations within the estuary but a substantially stronger fidelity to the geographic region of the delta. Therefore we predict the lagged identification rates to decrease rapidly in any of the specific survey sites, but be visibly higher and more stable in relation to the entire Pearl River Estuary. The pattern of lagged identification rates and calculated residence rates will facilitate the choice of appropriate population models for further mark-recapture analyses of demographic parameters an d the population size. Using lagged association rates and social network analyses we will quantify temporal stability of associations and community structure. Following the Gowans-Wursig-Karczmarski model (Gowans et al. 2008) we anticipate to find a dynamic fission-fusion society with few (if any) long-term bonds between individu als and great day-to-day lability in group sizes and membership. We also predict to find little or no evidence of genetic structure across the estuary using microsatellite and mtDNA markers due to high levels of dispersal and gene flow across the estuary. Because we predict groups to be composed of random associates, we expect genetic relatedness between individuals within groups to be low, but this will be determined in a follow-up study under GRF support.


List of Research Outputs

Andrews K.R., Karczmarski L. , Au W.W.L., Rickards S.H., Vanderlip C.A., Bowen B.W., Grau E.G. and Toonen R.J., Rolling stones and stable homes: Social structure, habitat diversity, and population genetics of the Hawaiian spinner dolphin (Stenella longirostris). , Molecular Ecology . Wiley-Blackwell, 2010, 19: 732-748.
Karczmarski L. , Dolphinid socio-behavioural variability: Does it matter for conservation ?, International Cetacean Conservation Symposium - Xiamen 2009 .
Karczmarski L. , Habitat driven divergence in population structure and geographic fidelity of humpback dolphins: Implicati ons for conservation , Strategic workshop of the Indo-Pacific Humpback Dolphin Conservation Task Force; Forestry Bureau and Fishery Agency of Council of Agriculture, Taiwan . 2009.
Karczmarski L. and Guissamulo A.T., Humpback dolphins in the south-western Indian Ocean: Habitat driven divergence in population structure and geographic fidelity. Does that matter for conservation ?, Indian Ocean Cetacean Symposium . 2009.
Karczmarski L. , Spinner dolphins off tropical East Africa: Group dyna mics, daily occurrence, and "unusual" pattern of behaviour., Indian Ocean Cetacean Symposium . 2009.
Karczmarski L. , Trials and tribulations of field research: What can we learn from others and our own work? , Workshop on population connectivity and conservation of Sousa chinensis off Chinese coast . 2010.
Reisinger R.R. and Karczmarski L. , Population size estimate of Indo-Pacific bottlenose dolphins in the Algoa Bay region, South Africa., Marine Mammal Science . Wiley-Blackwell, 2010, 26: 86-97.
Zhou K. and Karczmarski L. , Co-organizer and co-chair , Workshop on population connectivity and conservation of Sousa chinensis off Chinese coast . Nanjing, 2010.


Researcher : Karraker NE

Project Title: Importance of Amphibians to Stream Food Webs in Hong Kong
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 08/2007
Abstract:
Amphibians are important components of ecosystems, influencing nutrient fluxes, predator-prey dynamics, and other key ecological functions, and in some regions dominating vertebrate communities (Davic and Welsh 2004). In one study in the northeastern United States, the biomass of terrestrial salamanders was 2.6 times that of birds at the height of the breeding season and equal to that of small mammals (Burton and Likens 1975). In tropical forests of Puerto Rico, terrestrial frogs can attain densities greater than 20,000 per hectare (Stewart and Woolbright 1996). Despite a number of studies on the importance of amphibians to terrestrial ecosystems, their role in aquatic systems has received considerably less study with much of it focused on adults and their biomass relative to that of fish. Indeed, in some headwaters habitats, salamanders, not fish, have been shown to be the dominant vertebrat e predators (Petranka 1983, Lowe and Bolger 2002). In upper reaches of streams, larval amphibians may also replace fish as the dominant vertebrates, yet this relationship has not been well documented, particularly in tropical streams. In addition, the importance of larval amphibians, in terms of biomass, production, and trophic status relative to other stream omnivores has not been defined. In the past few decades, catastrophic declines of some amphibians have been reported from North and South America, Africa, Australia, and Europe, many inexplicably occurring in relatively pristine, well-protected areas, including national parks. In fact, nearly 200 (3%) of 6,000 described species are probably recently extinct, and 30% are considered globally threatened (Stuart et al. 2004, IUCN, Conservation International, and NatureServe 2006). Declines in amphibian populations have been associated with habitat destruction, pollution, invasive species, climate change, and disease. In particular, dramatic declines in Australia and Latin America have been associated with chytridiomycosis (Berger et al. 1998, Lips et al. 2006), an extremely pathogenic disease caused by the fungus Batrachochytrium dendrobatidis and reported in amphibians from all continents except Asia. As amphibian declines and extinctions are occurring at unprecedented rates, and still without consensus among the scientific community as to their causes in several regions (e.g. Pounds et al. 2006, Mendelson et al. 2006), it has become imperative to understand the ecological roles played by these organisms in regions where populations remain intact in order to determine how ecosystems may be impacted in the event of future declines. While production and trophic structure of tropical stream communities are increasingly being studied (e.g. Flecker 1992, Rosemond et al. 2001 , March and Pringle 2003), with extensive research occurring in Hong Kong (e.g. Salas and Dudgeon 2003, Mantel and Dudgeon 2004, Yam and Dudgeon 2005), this research has rarely included amphibians. In perhaps the first such study (Ranvestal et al. 2004), tadpoles exerted strong influences on both primary production and primary consumers. Tadpoles altered the biomass of algae, and mayfly abundances increased in the presence of tadpoles due to their removal of sediments from grazi ng surfaces. In a comparison of two streams in Panama, one with tadpoles and one in which tadpoles had been extirpated, tadpoles influenced the quantity and quality of suspended sediments and recycling of nitrogen, and these and other factors were probably responsible for a truncated food web in the stream without tadpoles (Whiles et al. 2006). Given that this latter study occurred following a recent and ongoing amphibian decline in the region, it reinforces the need for an increased understanding of the ecological importance of amphibians to aquatic ecosystems. In light of declining amphibian populations, a call has been made (Petranka and Kennedy 1999, Altig et al. 2007) to define the trophic relati onships of amphibians in their ecosystems, so as to better understand the potential ecological consequences of declines. The overarching goal of our research is to delineate the importance of amphibians to Hong Kong’s streams relative to other stream organisms and to understand the trophic status of amphibians within stream commun ities. In addition, we plan to assess the health of amphibian populations in Hong Kong. The specific objectives of this research are to characterize: (1) density, biomass, and production of Xenophrys brachykolos and Paa exilispinosa tadpoles within habitats relative to that of shrimps, snails, and aquatic insects; (2) describe the trophic relationships of X. brachykolos and P. exilispinosa relative to other consumers in the stream using stable isotope analysis; (3) and survey populations of X. brachykolos and P. exilispinosa for the fungal disease, chytridiomycosis. *References available upon request.


Project Title: Population Dynamics of Amphibians in Land-water Ecotones
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Completion Date: 08/2010
Abstract:
Amphibians are key components of ecosystems, influencing predator-prey dynamics, nutrient fluxes, and other important ecological functions, and in some regions dominating vertebrate communities (Burton and Likens 1975; Davic and Welsh 2004). In particular, anurans (frogs and toads) are considered to be one of the most important vertebrate group in terms of abundance and diversity in the tropics. In tropical forests of Panama, riparian frogs occurred at densities up to 1.35 sq m in Panama (Lips et al. 2003) and terrestrial frogs can achieve densities greater than 2.48 sq m in Puerto Rico (Stewart and Woolbright 1996). Despite a number of studies on the importance of amphibians to terrestrial ecosystems, their role in aquatic systems has received considerably less study. One study of stream frogs in Panama reported densities of 0.36 adult anurans per linear m of stre am (Ranvestal et al. 2004), yet information on adult anuran densities is limited for other regions of the tropics. Beginning in the 1980s, significant declines of amphibians have been reported from North and South America, Africa, Australia, and Europe, with many unexplained declines occurring in relatively undisturbed, well-protected areas, including national parks. In fact, nearly 200 (3%) of 6,000 described species are probably recently extinct, and 30% are considered globally threatened (IUCN 2006; Stuart et al. 2004). As these declines and extinctions are occurring at unprecedented rates, and still without consensus among the scientific community as to their causes (Mendelson et al. 2006; Pounds et al. 2006), it has become imperative to document the baseline ecology, population estimates, and densities of these organisms in regions where populations remain intact in order to be able to detect population declines if they begin to occur. Despite a long history of naturalists exploring the forests and streams of Hong Kong, the ecology of the 23 locally extant species of amphibians remains virtually unknown. While many of Hong Kong’s species also occur in Guangdong Province and a few are more broadly distributed throughout Southeast Asia, their ecology in these other regions is also poorly documented. The earliest studies (e.g. Boring 1934; e.g. Romer 1951) described the taxonomy of the region’s amphibians and reported natural history observations. The first comprehensive study of the distributions and habitat use of Hong Kong’s amphibians (Lau 1998) was conducted in the mid 1990s, but only the distribution data were published (Lau and Dudgeon 1999). Ongoing surveys are conducted each summer by the Hong Kong Government’s Agriculture, Fisheries, and Conservation Department, but such surveys only document presence of species and not abundances. Any conservation program for amphibian species must be developed based upon an understanding of ecology and demographic traits, yet were the need arise to develop such a program in Hong Kong our existing knowledge of these factors would be woefully inadequate. At a recent workshop in Hong Kong, scientists from Hong Kong and Guangdong Province met to prioritize amphibian species for conservation efforts in the region. Of 66 species evaluated, three species abundant in Hong Kong’s streams, the lesser spiny frog (Paa exilispinosa), the short-legged toad (Xenophrys brachykolos), and the green cascade frog (Rana chloronota) ranked in the top 15 in terms of conservation priority. For each of these species, it was determined that conservation plans could not be developed until baseline information on the ecology and population biology of these species was gathered. Such information would be needed for the initiation of ex situ conservation measures in the event that declines occur and such measures become necessary in the future. As part of another study, we have determined that tadpole densities and biomass in Hong Kong streams are higher than those reported from other regions of the world, and pilot surveys for adults have suggested that adult densities may also be exceptionally high. Because amphibians use terrestrial and aquatic ecosyste ms at different stages of their life cycles, high densities and biomass of amphibians may have important implications for the functioning of these systems, in terms of roles as predator and prey, nutrient fluxes, and food web dynamics. The specific objectives of this study are to characterize the population biology and densities of adult stream amphibians in Hong Kong by quantifyi ng (1) population sizes and densities, (2) movements, (3) age structure, and (4) diet. This proposed research will represent, to our knowledge, the first ecological study of the adults of several stream-breeding amphibian species and will shed light on their importance to Asian stream ecosystems. *References can be provided upon request.


Project Title: 2009 Joint Meeting of Ichthyologists and Herpetologists Importance of tadpoles to stream communities in tropical Asia
Investigator(s): Karraker NE
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Evaluating Amphibian Population Declines and Environmental Change in Hong Kong
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2009
Abstract:
1) Resurvey 165 sites to determine if they sustain the same or different species assemblages; 2) Identify changes in land cover and habitat degradation in and around these sites between 1996 and 2010; 3) Identify probable causes and ongoing threats to the persistence of species that have experienced population extirpations; 4) Develop a habitat restoration and reintroduction plan for the rough-skinned floating frog.


List of Research Outputs

Karraker N.E. , Associate Editor, Journal of Herpetology . 2010.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predator on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Annual Meeting of the Society for Conservation Biology . 2009.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Joint Annual Meeting of Ichthyologists and Herpetologists . 2009.


Researcher : Ko KW

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.


Researcher : Kong KF

List of Research Outputs

Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.


Researcher : Koutsaftis A

List of Research Outputs

Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Kuang R

List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.


Researcher : Kwok HYA

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y., Li J., Kwok H.Y.A. , Ge W. and Leung F.C.C. , A novel prolactin-like protein (PRL-L) gene in chickens and zebrafish: cloning and characterization of its tissue expression, General and Comparative Endocrinology . 2009, 166: 200-210.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Kwok KPWH

List of Research Outputs

Rhodes J.R., Grist E.P.M., Kwok K.P.W.H. and Leung K.M.Y. , A Bayesian mixture model for estimating intergeneration chronic toxicity, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong L.C., Kwok K.P.W.H. , Leung K.M.Y. and Wong C.K., Relative sensitivity distribution of freshwater planktonic crustaceans to trace metals, Human and Ecological Risk Assessment . 2009, 15: 1335-1345.


Researcher : Kwok WHKP

List of Research Outputs

Kwok W.H.K.P. and Leung K.M.Y. , Marine Pollution Bulletin Highly Cited Author Award 2005-2009, Marine Pollution Bulletin, Elsevier . 2010.


Researcher : Lam CW

List of Research Outputs

Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Lam PY

List of Research Outputs

Lam P.Y. , Glasser G., Gaudio E., Chow B.K.C. , Onori P., Franchitto A., Carpino G., Venter J., Francis H., Mancinelli R., Kopriva S. and Alpini G., Knock out of secretin receptors reduces large cholangiocyte hyperplasia in mice with extrahepatic cholestasis induced by bile duct ligation., Hepatology . 2010, 52: 204-214.


Researcher : Lam TY

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Repr oductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symp osium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Lia ng H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Lam TY

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproducti ve and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zhen g H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the ori gin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Lau CP

List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecologica l effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Lau CY

Project Title: Comparative aerobiology in outdoor environments in Hong Kong
Investigator(s): Lau CY, Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2008
Completion Date: 04/2010
Abstract:
Purpose of the project To compare the total microbial populations in the aerosphere of urban, sub-urban and rural areas in Hong Kong over a temporal scale of one year, identify community-shaping factor(s) by encompassing the changing meteorological factors and pollution conditi ons and assess the degree of necessity of including bio-aerosol data in air pollution assessment Key issues and problems being addressed Aerobiology is defined by Spieksma (1991) as ‘the study of organic particles, such as bacteria, fungal spores, very small insects and pollen, which are passively transported by the air’. Natural Resources Institutes (UK) (http://www.nri.org/) describes it as ‘the study of the movement and dispersal of living or once-living materials through the atmosphere’. Here aerobiology is interpreted as the general study of microbial lives (at any stages of their life cycles) and biologically-originated organic substances such as pollens that are associated within the aerosphere. Quality of air has long been proposed and studied for their potential risks to public health in the regards to the contemporary seriousness of air pollution. The adverse effects caused by abiotic elements in the air are comparatively broadly realized by the general public, than that caused by the biological counterpart (except air-transmitting diseases). For instance, respiratory symptoms resulted from allergy to airborne chemicals (Elberling et al. 2005) and deteriorated functioning of respiratory and cardiovascular systems and the possible fatality due to elevated levels of particulates (Mohanraj & Azeez 2004; World Health Organization 2005). Causal agents for infectious air-transmitting diseases form an evitable part of the aerobiology. Viral diseases, such as smallpox, measles, mumps, avian influenza (H5N1) (Tellier 2006) and severe acute respiratory syndrome (SARS) (Yu et al. 2004 for original article and correspondenc e) are carried passively by inorganic and organic particles (or droplets) that are present in the atmosphere. Taken the lesson from the outbreak of H5N1 and SARS, the pandemic potential of emerging infectious diseases should not be overlooked (Blachere et al. 2007). Awareness to viral taxa existing in the air is therefore urged in order to enhance our predictability over the epide mic of air-borne diseases caused by virus, to establish proper monitoring strategy (before, during and after the peak seasons for certain virus) and ultimately to prevent the panicking situation of widespread transmission. Air quality in Hong Kong is reflected via the means of an air pollution index system (or the API), which is responsible by the governmental unit, Environmental Protection Department. The API is a conversion value (in the scale of 0 to 500) based on the concentrations of 5 types of major chemicals measured on an hourly-basis at fourteen fixed monitoring stations (http://www.epd.gov.hk/ epd/). Similar monitoring systems are also in application in other countries elsewhere, namely Australia, Canada, Finland, Korea, Mexico, the Philippines, Singapore, Taiwan and the USA (http://www.epd.gov.hk/epd/). Nonetheless, studies found that comparable health problems could be induced or worsened by contacting airborne biolog ical sources, such as pollens (Newton et al. 1997), fungal spores (Bush & Portnoy 2001), moulds and mites (Zureik et al. 2002) and others (reviewed by Griffin 2007). As a result, to us, the inclusion of both abiotic and biotic parameters is going to provide a more comprehensiv e reflection on the air quality and therefore a better reference for planning our daily activities and taking essential measures if needed. Reference: Blachere, F.M., W.G. Lindsley, J.E. Slaven, B.J. Green, S.E. Anderson, B.T. Chen and D.H. Beezhold (2007) Bioaerosol sampling for the detection of aerosolized influenza virus. Influenza and Other Respiratory Viruses 1: 113-120 Bush, R.K. and J.M. Portnoy (2001) The role and abatement of fungal allergens in allergic diseases. J Journal of Allergy and Clinical Immunology 107: 430-440 Calderon, C., E. Ward, J. Freeman and A. McCartney (2002) Detection of airborne fungal spores sampled by rotating-arm and hirst-type spore traps using polymerase chain reaction assays. Aerosol Science 33: 283-296 Elberling, J., A. Linneberg, H. Mosbech, A. Dirksen, T. Menné, N.H. Nielsen, F. Madsen, L. Frolund and J. Duus Johansen (2005) Airborne chemicals cause respiratory symptoms in individuals with contact allergy. Contact Dermatitis 52: 65-72 Griffin, D.W. (2007) Atmospheric movement of microorganisms in clouds of desert dust and implications for human health. Clinical Microbiology Reviews 20: 459-477 Hernandez, M., S.L. Miller, D.W. Landfear and J.M. Macher (1999) A combined flurorochrome method for quantitation of metabolically active and inactive airborne bacteria. Aerosol Science and Technology 30: 145-160 Mohanraj, R. and P.A. Azeez (2004) Health effects of airborne articulate matter and the Indian scenario. Current Science 87: 741-748 Newson, R., K. Strachan, E. Archibald, J. Emberlin, P. Hardaker and C. Collier (1997) Effect of thunderstorms and airborne grass pollen on the incidence of acute asthma in Englan d, 1990-1994. Thorax 52: 680-685 Tellier, R. (2006) Review of aerosol transmission of influenza A virus. Emerg Infect Dis 12: 1657-1662 World Health Organization (2005) Particulate matter air pollution: how it harms health. Fact sheet EURO/04/05 Yu, I.T.S., Y. Li, T.W. Wong, W. Tam, A.T. Chan, J.H.W. Lee, D.Y.C. Leung and T. Ho (2004) Evidence of airborne transmission of the severe acute respiratory syndrome virus. The New Engl and Journal of Medicine 350: 1731-1739 [original article] Yu, I.T.S., Y. Li, T.W. Wong, W. Tam, A.T. Chan, J.H.W. Lee, D.Y.C. Leung and T. Ho (2004) Evidence of airborne transmission of the severe acute respiratory syndrome virus. The New England Journal of Medicine 351: 609-611 [correspondence] Zureik, M., C. Neukirch, B. Leynaert, R. Liard, J. Bousquet, F. Neukirch (2002) Sensitisation to airborne moulds and severity of asthma: cross sectional study from European Community respiratory health survey. BMJ 325: 411


List of Research Outputs

Lau C.Y. , Fund for world practical courses 'Bioinformatics and Comparative Genome Analysis', EMBO - Institut Pasteur Paris . 2009.
Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.


Researcher : Lee PP

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.


Researcher : Lee TO

Project Title: Transcriptional regulation of a nasopharyngeal carcinoma tumor suppressor: RASSF1A
Investigator(s): Lee TO, Chow BKC
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To elucidate the basal transcription regulation mechanisms of RASSFIA in normal - RASSF1A -expressing and RASSF1A -non-expressing NPC cells; to fine map the core promoter region of RASSF1 gene; identify transcription factor(s) that regulates RASSF1A expression.


Project Title: Molecular evolution of PACAP and VIP receptors in agnathan: Searching for the ancestr al PACAP/VIP receptor gene of vertebrates.
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 04/2010
Abstract:
To identify PACAP/VIP rece Background: Evolution of G protein-coupled receptors GPCRs Recently, the availability of genomic sequences from various genome projects has provided us with the opportunity to loc ate conserved sequence motifs that are responsible for specific functions via comparative approaches. This idea is applicable to investigating GPCRs, the biggest gene family in the animal kingdom. Using these data, the evolutionary origin of existing GPCRs, signaling pathway, ligand-receptor interactions, and other functionally relevant elements can be studied. GPCRs are crucial to a diversity of physiological functions by mediating extracellular signals and leading to cellular responses. The superfamily can be classified according to the GRAFS system, including: Glutamate, Rhodopsin, Adhesion, Frizzled and Secretin receptors [1]. The occurrence of GPCRs, as well as G-protein signaling pathways, could date back to ~1.2 billion years, from a common ancestor before plants, fungi and animals emerged. To-date, the phylogenetically “oldest” GPCRs that have been studied are fungal pheromone, cAMP-receptor-lik e and glutamate-receptor-like receptors [2]. Among these GPCRs, the rhodposin receptor family is the most studied. It was proposed that the first rhodopsin-like receptors appeared around 580-800 million years ago (MYA) in several protostome Bilateria, such as insects and nematodes . Afterwards, the number of GPCRs increased during evolution and the vertebrate GPCR numbers doubled comparing to invertebrates [3]. In other sub-families, especially the secretin-like receptors, their structure and evolution are not well characterized. PACAP, VIP and their receptors Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) are prominent neuropeptides that are structurally related [4]. They belong to the secretin/PACAP/VIP peptide family based on sequence identity. PACAP and VIP are widely distributed in the central nervous system and peripheral tissues. They have been found to exert many physiological and pathophysiological effects in development, growth, immune response, circadian rhythm, digestion, respiration, reproduction and heart functions. The actions of PACAP are mediated through the activation of specific receptors. There are three VIP/PACAP receptors in mammals: PAC1R, VPAC1R, and VPAC2R [6]. All these receptors are members of the secretin receptor family. The secretin receptor family can further be sub-divided into five branches via their interactions with the following peptides: a) Corticotrophin Releasing Factor (CRF); b) Secretin, VIP, PACAP, Growth Hormone-Releasing Hormone (GHRH) and recently characterized non-mammalian PACAP-related peptide (PRP); c) Glucagon, Glucagon-Like Peptides (GLP-1 or GLP-2), Glucose Insulinotropic Pept ide (GIP); d) Parathyroid Hormone (PTH). e) Calcitonin and Calcitonin Gene-Related Peptide (CGRP). Members in these subfamilies share high degree of amino acid sequence similarity within the seven transmembrane domains. The receptors in the secretin family have rather long N-termini, often between 60 and 80 amino acids, with conserved disulfide bridges [5]. The evolution of PACAP, GHRH and VIP genes was previously proposed in accordance to their structures and genomic organizations [7]. It was hypothesized that the mammalia n GHRHs were evolved from non-mammalian GHRH-like peptides which are encoded in the same gene with PACAP. Our recent study, however, provided new information regarding the evolution of PACAP, GHRH and VIP in non-mammalian vertebrates [8]. We convincingly showed that `a “real” GHRH, capable of stimulating growth hormone release, is distinctly present in another precursor protein, and hence in another gene, as in mammalian species. The so-called GHRH-like peptides are in fact PACAP-related peptides (PRPs). This conceptual revolution of the identities of GHRH and PRP in non-mammalian vertebrates sways the plausibility of the model previously proposed. For PACAP/VIP receptors, VPAC2R and PAC1R are located on the same chromosome in human and rat (human chromosome 7 and rat chromosome 4), whereas VPAC1R is located on human chromosome 3 and rat chromosome 8. Therefore, it was suggested that the evolution of PACAP/VIP receptors involved two rounds of gene duplication. In the first duplication, VPAC1R gene produced the common ancestor for VPAC2R/PAC1R, and in the second duplication, the ancestral gene of VPAC2R/PAC1R produced VPAC2R and PAC1R [9]. However, mapping of receptors in the chicken genome does not support this hypothesis. In the chicken genome, all PACAP/VIP receptors are located in chromosome 2, and PAC1R and VPAC1R are separated by our newly discovered PRPR gene. It is therefore possible that PAC1R is produced from duplicating VPAC1R directly. Meanwhile, as translocation of PACAP/VIP receptors are observed in some teleost models (zebrafish and fugu), information obtained from teleost is not suitable for investigating the evolution of PACAP/VIP receptors. Consequently, without information of PACAP/VIP receptors from lower vertebrates, especially from Agnathans, evolution of PACAP/VIP receptors remains to be established. Our Hypothesis: PACAP/VIP receptors are evolved from a common ancestor between tunicates and agnathans PACAP, VIP and their receptors are rarely studied in agnathans and invertebrates. The only published record is the identification of 2 PRP/PACAP genes in tunicate (Chelyosoma productum). It was thought that PACAP and their recept ors are emerged at/before protochordate. A cephalochordate genome, amphioxus (Branchiostoma floridae) provided additional information to the story. Amphioxus is a cephalochordate that is regarded as one of the closest living relative of vertebrates. Amphioxus shares several structural features with vertebrates like a dorsal, hollow notochord, segmental muscles and pharyngeal gill slits. Amphioxus genome was recently released by Joint Genome Institute. From the genomic data, CRF, PTH and calcitonin secretin-like receptor are found in amphioxus [10]. No receptors from the PACAP/VIP/secretin receptor subgroup could be identified in amphioxus genome. Also, by bioinformatic analysis, no member of PACAP/VIP peptide family is found in amphioxus. As it has been recently been suggested that tunicates could be more closely related to vertebrates than cephalochord ates based on phylogenetic analysis [11]. The missing PACAP/VIP receptors and ligands suggest strongly that the PACAP/VIP ligand-receptor were emerged after the separation of cephalochordates from tunicates and/or vertebrates. More important, genes encoding PACAP and VIP are predi cted from the sea lamprey genome by our preliminary data. Together with our recently identified VIP-like receptor in hagfish (Figure 1). We hypothesize that PACAP/VIP and their receptors are emerged from a common ancestor in the time between tunicates and agnathans evolution. Objectives: 1. ptors in lamprey and hagfish 2. To functional characterize these PACAP/VIP receptors 3. To propose a hypothesis showing the origin and evolution of PACAP/VIP receptor family.


Project Title: A role of secretin in the subfornical organ in sensing osmotic changes
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To investigate the role of secretin in SFO in regulating water intake; (2) To study the regulation of secretin gene in SFO under osmotic changes; (3) To substantiate the hypothesis that secretin is a part of the upstream pathway in SFO in Ang II-mediated control of volume homeostasis.


Project Title: Interactions of secretin and orexin in controlling food intake
Investigator(s): Lee TO, Chow BKC, Sun H
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Abstract:
Appetite is regulated by a complex system of centr al and peripheral signals which interact to modulate the individual response to nutrient ingestion. During a meal, satiety signals originated from the gastrointestinal tract reach the nucleus tractus solitaries (NTS) through the vagus nerve.The NTS then projects the signal to the arcuate nucleus (ARC) where these peripheral signal s are integrated with the central signals to control behavioral responses to a meal via downstream brain areas [1-3]. Lateral hypothalamuic area (LHA) is one of the brain areas controlled by ARC and is refereed as a feeding center in brain. Bilateral lesions in the LHA result in anorexia (lack of appetite) and animals may die of starvation after the lesions. It has been postulated that when body weight decreases or when the ARC senses “hunger”, LHA is activated to increase food intake. One of the mechanisms in LHA to increase appetite is to secret the orexigenic peptide, orexin. Two orexin peptides, orexin-A and orexin-B, are produced from a common prepro-orexin precursor [4, 5]. Orexin-A is a 33-residue peptide with two intrachain disulfide bonds, while orexin-B is a linear 28-residues peptide. Both peptides bind to two G protein-coupled receptors, orexin-1 (OX1R) and orexin-2 (OX2R) receptor. In vitro analysis showed that OX1R selectivity interacts with orexin-A while OX2R is able to interact with both orexins [6]. There are numerous studies suggesting that orexins could increase appetite. During fasting, the plasma orexin-A level and transcript level of prepro-orexin in LHA were increased significantly [4]. In passive immunoneutralization studies, infusion of antibodies of orexin-A reduced feeding in response to an overnight fast [7]. Moreover, the food intake induced by exogenously injection of orexin or fasting is decreased by anOX1R antagonist SB-334867 [8]. Orexin knockout mice (prepro-orexin gene deletion) ate less than wild-type mice, also sugge sting a physiologically role for endogenous orexin in the regulation of appetite [9]. However, it is interesting to note that the orexin knockout mice grew normally. This observation indicating that some other determinant of food intake/body growth may be involved to compensate the lost of the orexin pathways [9]. On the basis of their hypothalamic localization and their sequence similarity to secretin, orexin is also named as hypocretins. In the alignment (Fig.1), orexin shares an identical region with the C-terminus of secretin. Also, additional sequence identities can be found between N-terminal residues of secretin and C-terminal residues of orexins. Therefore, it has been suggested that orexin was evolved from secretin by circular permutation. The structural similarity between orexin and secretin suggested the possible interaction between secretin, orexin and their receptors. However, secretin did not show significant binding to orexin receptors or stimulate cellular response in CHO cells expressing human OX1R or OX2R [10]. In receptor binding studies using rat hypothalamus, secretin was able to displace [125I]orexin-A significantly [11, 12]. Recently, we have shown that secretin receptor (SCTR) is also expressed in hypothalamus [13, 14], therefore, it is possible that secretin and orexin-A in hypothalamus are competing for SCTRs but not orexin receptors. The potential role of secretin in appetite control was also suggested in our studies. By intrace rebroventricular (icv) injection of secretin into the lateral ventricle (LV), a significantly suppressed 24-hours food intake (Fig.2) was observed in both rats and wild-type (SCTR +/+) mice but not in SCTR knockout (SCTR-/-) mice. During fasting, the expression of both secretin and its receptor transcripts are decreased in rat hypothalamus (Fig.3). We have also shown the expressions of secretin and SCTR in LHA (Fig.4). These data indicated that secretin possesses an anorectic effect in rodents and this act ion may be involved the LHA. During fasting, the expression of orexin in LHA was increased while secretin expression was decreased. We propose here that the increased orexin not only stimulates the well known orexinergic pathways to enhance food intake, it may also inhibit the anorectic effect of secretin by competing with secretin on SCTR. To substantiate this hypothesis, we proposed to study the following: 1. To investigate interactions and signaling pathways of orexin and secretin with their receptors 2. To study structures responsible for ligand-receptor binding for orexin and secretin with their receptors 3. To evaluate the role of orexin in appetite control in SCTR knockout mice.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates
Investigator(s): Lee TO
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


Project Title: Implications of PACAP/VIP receptor gene duplications in early vertebrates
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To consolidate a revised evolutionary scheme for PACAP/GHRH/SCT receptors by characterizing these receptors in several animal models that are crucial to the understanding of early vertebrate evolution; 2) To investigate if PACAP/VIP receptors were evolved from a common ancestral gene after the separation of vertebrate lineage from cephalochordate/urochordate; 3) To substantiate that PHIR shares the same origin with VPAC2R, and it was evolved only after the teleost- specific genome duplication event; 4) To characterize fish SCTR and to search for SCTR in early vertebrates.


Project Title: The role of glucagon receptor family in the unique hyperglycermic activity of teleosts glucagon-l ike peptide 1.
Investigator(s): Lee TO
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
Glucagon and the glucagon-like peptides 1 (GLP-1) are paramount regulators of carbohydrate, fat and protein metabolism, as well as blood glucose level. They are encoded by the proglucagon gene together with glucagon-like peptides 2 (GLP-2). Even though the structures of these peptides are highly comparable, in mammals, the functions of glucagon and GLP-1 oppose to each other in blood glucose regulation. In mammals, glucagon is produced and secreted by the pancreatic α cells in response to low blood glucose levels and it serves as the major counter-regulatory hormone to insulin(1). Among vertebrate s, the major physiological functions of glucagon appear to be conserved. Both fish and mammalian glucagons elevate blood glucose level via inducing hepatic glycogenolysis and gluconeogeneisis(2-3). While the regulatory function of glucagon on insulin has been maintained from fish to mammals, GLP-1 has changed its physiological function. In mammals, GLP-1 is an incretin hormone that stimulates insulin secretion from pancreatic β cells. In disparity, fish GLP-1, produced in both pancreas and intestine, shows a glucagon-like activity contrasting the insulin-l ike activity of mammalian GLP-1(4-5). Bowfin fish (Amia calva) GLP-1 fails to stimulate insulin release from pancreas and it was found to be hyperglycermic and glucagon-like(6-7). Fish GLP-1 accelerates glucose transport and curtails glucose oxidation in enterocytes and it was found to elicit an increase in cAMP level in brain and enterocytes. GLP-1 also acts directly on the liver by supplementing the action of glucagon, including glycogenolysis, gluconeogenesis and lipolysis, but no such increase in cAMP level is noted in isolate d hepatocytes in vitro(8). Therefore, GLP-1 is found to have acquired and subsequently lost gluconeogenic activity during the evolution as illustrated by its contrasting functions in fish and mammals. This leads to possibility of either the peptide or receptor being responsible. In the case of the proglucagon-derived peptides, the high conservation of primary structure indicates strong evolutionary pressure to preserve function. Hence, the receptor may play a greater contributing factor as to why there was a change in biological activity. To elicit their biological functions, glucagon and GLPs interact with corresponding receptors: glucagon receptor (Glu-R), GLP-1 receptor (GLP-1R) and GLP-2 receptor (GLP-2R). Collectively, these receptors belong to a class II B superfamily of G protein-coupled receptor s family. To date, although a range of proglucagon ligand and receptor sequences are known, most research has been focused on mammals and the information regarding receptors in fish and frogs is relatively sparse. In fish, the goldfish (Carassius auratus) and zebrafish (Danio rerio) are the only species in which molecular cloning of glucagon and/or GLP-1 receptors has been successfully achieved(4, 9), whilst fugu (Takifugu rubripes), pufferfish (Tetraodon nigroviridis) and medaka (Oryzias latipes) comprise of the remaining species where receptor sequences have been predicted by data mining of their respective genomes. It was previously hypothesized that as a result of the fish-sp ecific gene duplication event early in teleost evolution prior to species diversification, a duplicate Glu-R acquired GLP-1 binding ability whilst retaining glucagon binding ability, thus giving rise to receptors currently recogni zed as “fish GLP-1Rs” and are paralogous to Glu-Rs. The original GLP-1R in fish was also thought to have been lost from the fish lineage(10). However by extensive data mining of the fugu, pufferfish and medaka genomes, we have been able to predict sequences resembling those of known GLP-1Rs, forming a separate GLP-1R group. In our phylogenetic analysis, with the exception of fish GLP-1R-likes, all glucagon superfamily receptors can be grouped based on subtype. The results indicate fish GLP-1R-likes to be closely related to fish Glu-Rs and are clustered together within the Glu-R group. This suggests that a “true” GLP-1R in fish does indeed exist and was not lost. Based on this finding, we believe previously identified “fish GLP-1Rs” should be termed as “fish GLP-1R-likes”. Non-fish vertebrates have true GLP-1Rs exhibiting high resemblance in both phylogenet ic analysis and physiological function. Therefore, this may suggest that the true fish GLP-1R is non-functional or functionally different to mammalian counterparts, thus resulting in GLP-1’s unique glucagon-like activity in fish. To substantiate this hypothesis, we proposed to study the following: 1. Isolate and express the Glu-R, GLP-1R, and GLP-1R-like receptors in three teleo st animal models: goldfish (Carassius auratus), pufferfish (Tetraodon nigroviridis) and zebrafish (Danio rerio), 2. Evaluate the ligand-specificity and signaling properties of the identified teleost glucagon and GLP-1 receptors, 3. Study the role of the conserved motifs of the receptors by mutagenenesis-based strategy.


List of Research Outputs

Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Lee T.O. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.


Researcher : Lee WWM

Project Title: Interaction and ultrastructure of cell junction proteins in the testis
Investigator(s): Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2006
Completion Date: 08/2009
Abstract:
(1) What are the functional and structural relati onship between tight junctions and basal ectoplasmic specialization (ES) structural protein complexes at the blood-testis barrier (BTB) ? Are there any common adaptors that structurally and functionally link the cadherin/catenin/c -Src/MTMR2, the nectin/afadin/ponsin, and the TJ protein complexes together to regulate BTB dynamics? (2) What are the molecular composition of the laminin α(?)β(?)γ3 receptors and its associated peripheral proteins, which interac t with α6β1 integrin at the apical ES?


Project Title: Extracellular matrix proteins and cell junction dynamics in the testis.
Investigator(s): Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Abstract:
To investigate the role of collagens and collagen fragments in BTB junction dynamics. Can fragments of collagen IV perturb Sertoli cell functions, such as Sertoli cell tight junction-barrier, MMP-9 and TIMP-1 productions? To investigate the role of proteases and protease inhibitors in BTB junction dynamics. Can a disruption of the protease and protease inhibitor homeostasis modulate cytokine-induced transient BTB damage in the seminiferous epithelium?


Project Title: Paracrine regulations of blood-testis barrier dynamics
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2009
Completion Date: 12/2009
Abstract:
The blood-testis barrier (BTB) is formed by cell junctions between adjacent Sertoli cells in the testis. It is important for several reasons. First, it creates a microenvironment for germ cell development. Second, it insulates meiotic germ cells from the systemic cir culation, thereby protecting them from potential cytotoxic substances and autoimmune recognition, and confers apical-basal polarity. Third, it must open and close at time interva ls to allow the passage of preleptotene spermatocytes from the basal to adluminal compartment. Fourth, the delivery of drugs or contraceptives must take into account the constraints imposed by the BTB [1]. In this proposal, the P.I. seeks to examine how cytokines (e.g., tumor necrosis factor-a, TNF-a and transforming growth factor-b3, TGF-b3) are working in coordination with testosterone to regulate the BTB dynamics in adult rat testes. This allows the germ cells to traverse across the BTB, while at the same time still maintaining the barrier integrity. Recent studies from the P.I.’s laboratory have shown that TNFa and TGF-b3 disrupt the Sertoli cell tight junction (TJ)-permeability barrier in vitro and the BTB integrity in vivo [2] (for reviews, see [3]). It is plausible that cytokines (e.g., TNFa)secreted by Sertoli and germ cells into the BTB microenvironment induce the “opening” of the BTB to facilitate preleptotene spermatocyte migration that occurs at stages VII-VIII of the epithelial cycle. Along the line, it has also been shown that testosterone promotes the BTB integrity based on studies using the Sertoli cell specific androgen receptor knockout (SCAR KO) mouse model. For instance, SCAR KO mice are infertile due to spermatogenic arrest before the first meiosis [4] and the BTB in these mice was shown to be impaired plausibly as the result of reduced integral membrane proteins at the BTB. This promoting effect of testosterone on the BTB in vivo is also consistent with earlier in vitro studies that androgen promotes the Sertoli cell TJ-barrier and cell adhesion [5]. Furthermore, the expression of androgen receptor in adult testes is also stage-specific, being highest at stages VII-VIII at the time of preleptot ene spermatocyte migration across the BTB, similar to TGF-b3 and TNF-a. The effects of cytokines and testosterone on testicular functions are multiple. However, in a latest study [6], the P.I. has shown that both cytokines and testosterone accelerate the kinetics of integral membrane protein endocytosis in Sertoli cells in vitro with functional BTB. In this instance, cytokines induce the endocytosed proteins (e.g., occludin) to late endosomes for degradation whereas testosterone promotes their recycling back to the cell surface. It is postulated that at defined stages of the spermatogenic cycle, cytokines contribute to the “destabilization” of the TJ fibrils at the apical portion of the migrating pr eleptotene spermatocytes, facilitating cell migration; whereas androgen promotes the “transcytosis” of the internalized integral membrane proteins from the apical to the basal region of the migrating germ cells to facilitate the assembly of new TJ fibrils, so as to maintain the im munological barrier during the epithelial cycle. How do testosterone and cytokines exert their differential actions on this junction dynamics is not known. However, this is likely mediated via their effects on extracellular matrix (ECM) components: collagens, proteases (e.g., matrix metalloproteases, MMPs, such as MMP-9), and protease inhibitors (e.g., tissue inhibitors of metalloproteases, TIMPs), thereby reducing the steady-state levels of integral membrane proteins at the BTB, and destabilizing the BTB to facilitate germ cell migration. The P.I. has the following specific aims to generate a comple te study to vigorously examine the actions of testosterone and cytokines on BTB dynamics at the cellular and subcellular levels. In this seed funding period, work on Specific Aim 1 will be performed. After which, a full proposal (Specific Aims 1 and 2) with initial results and backup findings from [6] will be submitted for GRF funding in the 2010-2011 exercise. Specific Aim 1: To investigate how cytokines are working in concert with extracellular matrix (ECM) proteins, such as collagens, proteases (e.g., MMP-9), and protease inhibitors (e.g., TIMP-1), to determine the steady-state levels of inte gral membrane proteins at the BTB, inducing transient BTB “opening” to facilitate preleptotene spermatocyte migration during spermatogenesis. Specific Aim 2: To delineate the mechanism(s) utilized by the testis to maintain the BTB integrity regarding the opposing effects of cytokines (or NC1 domain) and testosterone on the ba rrier function during the seminiferous epithelial cycle of spermatogenesis. Literature cited: 1. Lui WY and Lee WM (2008) Mechanisms of reorganization of cell-cell junctions in the testis. Frontiers in Biosciences 13:6775-6786. 2. Li MWM, Xia WL, Mruk DD, Wang Q, Yan HHN, Siu MKY, Lui WY, Lee WM and Cheng CY (2006) TNFa can reversibly disrupt the blood-testis barrier (BTB) and impair Sertoli-germ cell adhesion – a novel mechanism to regulate junction dynamics during sperm atogenesis. Journal of Endocrinology 190:313-329. 3. Xia WL, Mruk DD, Lee WM and Cheng CY (2005) Cytokines and junction restructuring during spermatogenesis – a lesson to learn from the testis. Cytokine & Growth Factor Reviews 16:469-493. 4. De Gendt K, Swinnen JV, Saunders PT, Schoonjans L, Dewerchin M, Devos A, Tan K, Atanas sova N, Claessens F, Lecureuil C, Heyns W, Carmeliet P, Sharpe RM, Verhoeven GA (2004) Sertoli cell-selective knockout of the androgen receptor causes spermatogenic arrest in meiosis. Proc. Natl. Acad. Sci. USA 101: 1327-1332. 5. Zhang JY, Wong CH, Xia WL, Mruk DD, Lee NPY, Lee WM and Cheng CY (2005) Regulation of Sertoli-germ cell adherens junction dynamics via changes in prote in-protein interactions of the N-cadherin-b-catenin protein complex which are possibly mediated by c-Src and MTMR2: an in vivo study using an androgen suppression model. Endocrinology 146:1268-1284. 6. Yan HHN, Mruk DD, Lee WM and Cheng CY (2008) Blood-testis barrier dynamics are regulated by testosterone and cytokines via their differential effects on the kinetics of protein endocytosis and recycling in Sertoli cells. FASEB J 22:1945-1959.


Project Title: 34th FEBS (Federation of the European Biochemical Societies) Congress IFN-gamma and TNF-alpha downregulate the expression of Junctional Adhesion Molecule-C (JAM-C) through transcriptional and post-translational controls
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Cell junction dynamics at stage VIII of the seminiferous epithelial cycle -- coordination between spermiation and blood-testis barrier restructur ing
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2009
Abstract:
During spermatogenesis, preleptotene/leptotene spermatocytes at the basal compartment traverse the blood-testis barrier (BTB) at stages ~VIII-IX of the seminiferous epithelial cycle in adult rat testes, entering the adluminal compartment for further development [1]. This event takes place concurrently with spermiation wherein fully developed spermatids (i.e., spermatozoa) detach from the epithelium at the luminal edge, enterin g the tubule lumen for their eventual maturation in the epididymis. The P.I. seeks to study the mechanism that regulates and coordinates these events. The idea was based on a recent study in which a blockade of the laminin function at the apical ES by specific antibodies led to spermatid exfoliation and BTB restructuring [2] showing that a disruption of the apical ES may lead to a transient BTB disruption. This illustrates a plausible physiological link between these two ultrastr uctures. The apical ES is a testis-specific adherens junction (AJ) type that anchors developing spermatids to the Sertoli cell in the epithelium during spermatogenesis [3]. It has properties of both AJ and focal contacts. For instance, many proteins that are restricted to the cell-matrix interface at the focal contacts, such as integrins, laminins, and collagens are found at the apical ES. In adult rat testes, one of the major cell adhesion complexes at the apical ES is the laminin-333/alpha6beta1 integrin complex [3]. Indeed, laminin gamma3 chain was first identified as a non-basement laminin at the apical ES in mouse testes [4]. Subsequent studies in adult rat testes have shown that laminin gamma3, alpha3 and beta3 chains residing in the elongating/elongated spermatids form a protein complex known as laminin-333 (2), which is the bona fide partner of the alpha6beta1-integrin restricted to Sertoli cells [5,6] constituting the laminin-333/alpha6beta1-integrin adhesion complex at the apical ES. When the laminin-333 function was compromised by using blocking antibodies, spermatid sloughing from the epithelium was detected [3]. Furthermore, this laminin/integrin complex is associated with proteases: matrix metalloprotease-2 (MMP-2), membrane-type 1 (MT1)- MMP; and tissue inhibitor of metalloproteases-2 (TIMP-2) [7]. These findings suggested that the activation of MMP-2 by MT1-MMP and TIMP-2 at the apical ES during spermiation could cleave laminin-333 to generate the biologically active laminin fragments. Indeed, there are reports illustrating that fragments of laminin chains that arise under physiological and pathophysiological conditions are biologically active peptides, regulatin g cell migration, protein production and/or activation, inflammatory responses, and others [8-10]. Thus, it is possible that fragments of laminin chains released from the apical ES during spermiation could regulate the BTB in the testis. This has prompted us to study the effects of laminin fragments on BTB restructuring. Subsequently, our latest results published in PNAS [11] have shown that specific laminin fragments: lamini n gamma3 chain domain IV (Lam g3DIV) and laminin beta3 chain domain I (Lamb3DI) are bioactive peptides regulating BTB restructuring. This study provides compelling evidence that during spermatogenesis there exists an autocrine-based regulatory axis (apical ES-BTB-hemidesmosome) coordinating spermiation and BTB restructuring. In this proposal, the PI provides a plan of follow-up studies to address the underlying mechanisms since this “apical ES-BTB-hemidesmosome” axis must be vigorously characterized, so that this information can be helpful to investigators in the field to study the biology and regulation of spermatogenesis. Additionally, this application will shed lights in the development of innovative male contraceptive, such as by using the laminin peptide to compromise spermatogenesis. This proposal is innovative, hypothesis driven, mechanistic in nature and based on recent findings published in leading journals. Specific Aim 1. Origin of the laminin fragments and their regulation: Is the production of laminin fragments stage-specific? Specific Aim 2. Mechanism(s) of action of the laminin fragment: (a) Is it mediated via integrin receptor and/or non-integrin-based proteins? Are non-receptor protein tyrosine kinases (e.g., FAK and c-Src) at the BTB and apical ES serve as the downstream signal transducers? Literature cited: 1. Russell LD. Movement of spermatocytes from the basal to the adluminal compartment of the rat testis. Am J Anat 1977; 148, 313-328. 2. Yan HHN, Cheng CY. Laminin a3 forms a complex with b3 and g3 chains that serves as the ligand for a6b1-integrin at the apical ectoplasmic specialization in adult rat testes. J Biol Chem 2006; 281 17286-17303. 3. Yan HHN, Mruk DD, Lee WM, Cheng CY. Ectoplasmic specialization: a friend or a foe of spermatogenesis? BioEssays 2007; 29, 36-48. 4. Koch M, Olson PF, Albus A, Jin W, Hunter DD, Brunken WJ, Burgeson RE, Champliaud MF. Characterization and expression of the laminin g3 chain: a novel, non-ba sement membrane-associated, laminin chain. J Cell Biol 1999; 145, 605-618. 5. Palombi F, Salanova M, Tarone G, Farini D, Stefanini M. Distribution of b1 integrin subunit in rat seminiferous epithelium. Biol Reprod 1992; 47, 1173-1182. 6. Salanova M, Stefanini M, De Curtis I, Palombi F. Integrin receptor a6b1 is localized at specific sites of cell-to-cell contact in rat seminife rous epithelium. Biol Reprod 1995; 52, 79-87. 7. Siu MKY, Cheng CY. Interactions of proteases, protease inhibitors, and the b1 integrin/laminin g3 protein complex in the regulation of ectoplasmic specialization dynamics in the rat testis. Biol Reprod 2004; 70, 945-964. 8. Koshikawa N, Schenk S, Moeckel G, Sharabi A, Miyazaki K, Gardner H, Zent R, Quaranta V. Proteolytic processing of laminin-5 by MT1-MMP in tissues and its effects on epithelial cell morphology. FASEB J 2004; 18, 364-366. 9. Ogawa T., Tsubota Y., Hashimoto J., Kariva Y., Miyazaki K. The short arm of laminin g2 chain of laminin-5 (laminin -332) binds syndecan-1 and regualtes cellular adhesion and migration by suppressing phosphorylation of integrin b4 chain. Mol Biol Cell 2007; 18, 1621-1633. 10. Remy L., Trespeuch C., Bachy S., Scoazec J.Y., Rousselle P. Matrilysin 1 influences colon carcinoma cell migration by cleavage of the laminin-5 b3 chain. Cancer Res 2006 ; 66, 11228-11237. 11. Yan HHY, Mruk DD, Wong EWP, Lee WM, Cheng CY. An autocrine axis in the testis that coordinates spermiation and blood-testis barrier restructuring during spermatogenesis. Proc Natl Acad Sci USA 2008; 105: 8950-8955.


List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents bl ood-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Lui W.Y. and Lee W.W.M. , Molecular mechanisms by which hormones and cytokines regulate cell junction dynamics in the testis, Journal of Molecular Endocrinology . 2009, 43: 43-51.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Lee YK

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Liao S. , Liu Y. , Siu D.C.W. , Zhang Y. , Lai K.W.H. , Au K.W. , Lee Y.K. , Chan Y.C. , Yip P.M.C. , Wu E.X. , Lau C.P. , Wu Y., Li R.A. and Tse H.F. , Pro-arrhythmic Risk of Embryonic Stem Cell-Derived Cardiomyocytes Transplantation in Infarcted Myocardiu m. Heart Rhythm. , 2010.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Lee YK

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Liao S. , Liu Y. , Siu D.C.W. , Zhang Y. , Lai K.W.H. , Au K.W. , Lee Y.K. , Chan Y.C. , Yip P.M.C. , Wu E.X. , Lau C.P. , Wu Y., Li R.A. and Tse H.F. , Pro-arrhythmic Risk of Embryonic Stem Cell-Derived Cardiomyocytes Transplantation in Infarcted Myocardium. Heart Rhythm. , 2010.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Leung FCC

Project Title: Cloning of the viral genes from the newly identified SARS coronavirus
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: VCO SARS Research Fund
Start Date: 07/2003
Abstract:
To clone all the viral gene into vector and these cloned genes will be then be used as reagents by us and other as the first step for investigation.


Project Title: Development of a rapid high throu ghput RT-PCR assay to detect SARS-CoV
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: VCO SARS Research Fund
Start Date: 07/2003
Abstract:
To develop a 96-wells RT-PCR platform assay for the detection of the coronavirus.


Project Title: Isolation and characterization of a PCV2 virus causing postweaning multisystemic wasting syndrome in pigs
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To isolate and characterize the PCV2 virus that causes the Postweaning multisystemic wasting syndrome (PMWS) in pigs.


Project Title: International Conference on Farm Animal Endocrinology Characterization of the 5'-Flanking Transcriptional Regulatory Region of the Chicken Growth Hormone Gene
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2004
Abstract:
N/A


Project Title: Characterization of the angiotensi n-converting enzyme 2 receptors from various animals and the use of pseudotyped virus to correlate the receptor-binding to susceptibility of SARS-CoV infection
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: Research Fund for the Control of Infectious Diseases - Full Grants
Start Date: 01/2007
Abstract:
To identify the susceptible animals to severe acute respiratory syndrome associated coronavirus SARS-CoV and SARS-like bat CoV through a molecular approach.


Project Title: 2009 Conference for Research Workers in Animal Diseases A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)
Investigator(s): Leung FCC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 12/2009
Abstract:
N/A


List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Hui R.K.H. , Wang K.X. and Leung F.C.C. , Effects Of Nsp2 Deletions On PRRSV Genome And Replicatoin Efficiency., International PRRS Symposium 2009, National Pork Board . 2009.
Leung F.C.C. , American Association for the Advancement of Science (AAAS) Fellow 2009 . 2009.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Wang Y., Li J., Kwok H.Y.A. , Ge W. and Leung F.C.C. , A novel prolactin-like protein (PRL-L) gene in chickens and zebrafish: cloning and characterization of its tissue expression, General and Comparative Endocrinology . 2009, 166: 200-210.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.
Xi Y. , Huang B. , Djurisic A. , Chan M.N. , Leung F.C.C. , Chan W.K. and Au D.T.W., Electrodeposition for antibacterial nickel-oxide-based coatings, Thin Solid Films . Amsterdam, Elsevier B.V., 2009, 517: 6527-6530.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Leung HYM

List of Research Outputs

Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.


Researcher : Leung KCJ

List of Research Outputs

Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Leung KMY

Project Title: Ecology, physiology and toxicology of Stomatopoda in Hong Kong
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 09/2002
Abstract:
To document the biodiversity of Stomatopoda in the subtital marine environment of Hong Kong; to study the population dynamics, ecology and physiology of five commercially important stomatopod species, Harpiosquilla harpax, Dictyosquilla foveolata, Miyakea nepa, Oratosquill a oratoria and Oratosquillina interrupta in the selected study locations; to investigate if there are any seasonally variations in the concentrations of pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the tissues of these five stomatopod species; to test and establis h the relationship between fitness parameters, physiological indices and pollution burdens in the stomatopods.


Project Title: Aquatic ecological risk assessment: comparison of tropical and temperate species sensitivity to chemicals
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 09/2002
Abstract:
To compare the species sensitivity distributions for temperate and tropical organisms exposed to individual chemicals; to identify specific chemical groups, classified by mode of action or physico-chemical properties, for which technically sound estimates of tropical PNECs can be made/predicted on the basis of temperate toxi city data; to validate these predictions through the generation/compilation of extensive ecotoxicity datasets for a number of mo del substances; to establish a procedure to estimate tropical PNECs for the selected substances. Existing data will be supplemented by new ecotoxicity data where these are likely to result in improved confidence in the estimation of tropical PNECs.


Project Title: Ecotoxicity of binary mixtures of antifouling biocides and copper to selected tropi cal marine organisms: Implications for derivation of environmentally realistic water quality criteria
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 11/2007
Abstract:
To investigate the acute and chronic toxicities of eight common synthetic antifouling biocides alone and in combination with copper (Cu) to a suite of tropical/sub-tropical marine organisms (including plant, invertebrate and vertebrate). To derive environmentally relevant water quality criteria (WQC) for these compounds at various environmentally realistic Cu levels (0-20 µg/L) using a novel approach.


Project Title: Time-series and spatial statistical studies on marine water quality monitoring data in Hong Kong: Implications of the effectiveness of environmental policy and management, and definition of water pollution control zones
Investigator(s): Leung KMY, Li WK
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2010
Abstract:
1. To development of time-series models to partially characterise and identify the critical time points in terms of water quality improvement over the past; and 2. To explore suitable spatial models to redefine the water pollution control zones for better water quality management in Hong Kong.


Project Title: The Experimental Biology 2010 Meetin g A fitness cost for thermal tolerance in a marine copepod: Implication on biological effects of global warming
Investigator(s): Leung KMY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 04/2010
Completion Date: 04/2010
Abstract:
N/A


List of Research Outputs

Bao W.W. , Qiu J.W., Lam M.H.W. and Leung K.M.Y. , Acute toxicities of five commonly used antifouling booster biocides to selected tropical/subtropical marine species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Acute toxicities of zince pyrithione alone and in combination with copper to marine autotrophic species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Leung K.M.Y. and Lui G.C.S. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.
Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Kwok W.H.K.P. and Leung K.M.Y. , Marine Pollution Bulletin Highly Cited Author Award 2005-2009, Marine Pollution Bulletin, Elsevier . 2010.
Leung K.M.Y. , A fitness cost for thermal tolerance in a marine copepod: implication on biological effects of global warming, an invited lecture at at the Mini-Symposium on Biolo gical Consequences of Global Change in the Experimental Biology 2010 congress, which was organised by the American Association of Anatomists and International Society of Zoological Sciences, was held during 24-28 April 2010 at Anaheim Convention Centre, Anaheim, U.S.A. . 2010.
Leung K.M.Y. and Bao W.W. , A unifying model for predicting temperature-dependent toxicity of pollutants: an insight to the interacting effect of climate change and chemical pollution, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung K.M.Y. , Award for Service Contribution 2009-2010, Faculty of Science, The University of Hong Kong . 2010.
Leung K.M.Y. , Comparison of tropical and temperate aquatic species sensitivities to chemicals: implications for ecological risk assessment and water quality management, an invited plenary lecture at the Workshop on Ecosystem Risk Assessment, which was organised by the Australasian Society for Ecotoxicology and held during 14-15 June 2010, in Madang, Papua New Guinea . 2010.
Leung K.M.Y. , Endocrine disrupting chemicals (EDCs) in Hong Kong waters: What we know, don't know and should know, an invited lecture at the International Symposium on the Biomonitoring and Biomarker of EDCs in Coastal and Marine Environments, organised by Ministry of Land, Transport and Maritime Affairs, Korea and National Eisheries Research and Development Institute, held on 17 September 2009, in Busan, Korea . 2009.
Leung K.M.Y. , Environmental risk assessment: a major paradigm shift in environmental management, and Field species distribution for detection of environmental changes, two invited lectures delivered at the United Nations' PEMSEA Regional Training Course on Novel Technology for Marine Environmental Management, organised by Partnerships in Environmental Management for the Seas of East Asia, held during 19-21 November 2009, in Manila, Philippine s . 2009.
Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung M.C.C., Hui J.C.T., Zurcher N.A. , Yuan D.X. and Leung K.M.Y. , Trace metals and methyl mercury in sharks' fins: potential health risk for consumers, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zool ogy, July 7-10, 2009. Beijing, China . 2009.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea: Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Qiu J.W., Chan K.M. and Leung K.M.Y. , Assessment of tributyltin contamination in Hong Kong coastal waters using Thais clavigera as a biomonitor: an update on the spatial and seasonal patterns, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Rhodes J.R., Grist E.P.M., Kwok K.P.W.H. and Leung K.M.Y. , A Bayesian mixture model for estimating intergenerat ion chronic toxicity, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wong L.C., Kwok K.P.W.H. , Leung K.M.Y. and Wong C.K., Relative sensitivity distribution of freshwater planktonic crustaceans to trace metals, Human and Ecological Risk Assessment . 2009, 15: 1335-1345.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enha nce uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor response s in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City Universit y of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Yeung W.Y. and Leung K.M.Y. , Effects of tissue types, animal size, nutritional status and metal exposure on the RNA/DNA ratio in various tissues to the green-lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Yeung W.Y. and Leung K.M.Y. , Spatio-temporal variations in metal accumulation, RNA/DNA ratio, energy reserves and condition index in transplanted green-lipped mussels Perna viridis in sub-tropical Hong Kong waters, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Zhao Z.Y., Gu J.D. , Li H.B., Li X.Y. and Leung K.M.Y. , Disinfection characteristics of the dissolved organic fractions at several stages of a conventional drinking water treatment plant in Southern China, Joural of Hazardous Materials . 2009, 172: 1093-1099.


Researcher : Leung TK

List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.


Researcher : Leung TY

List of Research Outputs

Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zoology, July 7-10, 2009. Beijing, China . 2009.
Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea: Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Li ETS

Project Title: Nutritional benefits of dietary fiber supplementation in hospitalized geriatrics
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1997
Abstract:
To improve gentle bowel fitness, relieve constipation and improve serum lipid profile of institutionalized geriatric patients via dietary fiber supplementation.


Project Title: An evaluation on the antioxidant effects of Lycium barbarum L. and its supplementation on cataract formation in rats
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To systematically examine the antioxidant properties of Lycium barbarum L. and evaluate the effect of its supplementation on cataract development in rats.


Project Title: Anti-cataract effects of Lycium barbarum L and Momordica charantia
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To systematically examine the antioxidant properties of Lycium barbarum L. and Momordica charantia and evaluate the effects of supplementation on cataract development in rats.


Project Title: The CSCN 5th Annual Scientific Meeting Bitter Melon Supplementation Changes Expression of Genes Controlling Lipid Metabolism in Diet-induced Obese Rats
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2006
Abstract:
N/A


Project Title: Offsetting the Adverse Effects of Maternal Overnutrition by Bitter Melon Supplementation
Investigator(s): Li ETS
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
Metabolic syndrome (MS) posts a serious health concern worldwide. The etiology of MS is complex and a lot of attention has been given to the impact of perinatal nutrition because substantial evidence suggest maternal nutrition has a trans-generation effect on disease risk. In fact, both under- and overnutrition are known to predispose offspring to develop phenotypes characteristics of MS. This study will focus on examining in utero overnutrition as a predisposing factor. High fat intake is acknowledged to attribute to the high incident of chronic degenerative disease s. Fetal programming effect is well established. Offspring of rats fed a high fat diet during pregnancy had impaired glucose homeostasis. There is a positive association between birth weight and later BMI (and obesity). furthermo re, macrosomic infants have higher cardiovascular disease risk. Hence, the relationship between birth weight and type 2 diabetes (T2D) is U-shape. It should be reminded that increasing prevalence and younger age of MS onset takes place at time when fat consumption follows a decreasing trend. However, the consumption of another macronutrient, fructose, had steadily increased in the past 30 years. High fructose diet is also know n to precipitate MS. In addition to changes in energy and macronutrient supply, developmental programming can take place with perinatal exposure to certain dietary ingredients. For instance, isoflavones given to dams during pregnancy and lactation provide cardioprotection to offspring in adulthood. Reduced risk of obesity has also been demonstrated in Avy mouse. When genistein was given to a/a females two weeks prior to mating with Avy/a males, the coat color of the heterozygous yellow agouti pups was shifted to pseudoagouti. These results led us to reason that other bioactive ingredients, known to influence energy metabolism and glucose homeostasis, introduced at pregnancy and lactation might be benef icial. In this context, we have the experience in the use of botanical / herbal preparations in counteracting the phenotype characteristics of MS. We have documented the beneficial effects of bitter melon juice and its supplementation in the diet results in lower blood glucose and triglyceride; and less body fat accumulation. The molecular mechanisms involved include elevated expression of uncoupling protein in white adipose tissue and lipolytic enzymes in skeletal muscles. Whether bitter melon supplementation could offset the adverse metabolic effect of fructose has not be examined. The overall objective of this proposal is to test the hypothesis that supplementation of bitter melon extract from pe riconceptual through lactation period can alleviate the negative impact of maternal overnutrition induced by fructose on chronic disease risk of offspring. Specific objectives: a. To establish the effects of maternal bitter melon supplementation on fetal programming in offspring from fructose fed dams. c. To examine the molecular mechanisms that counteract metabolic syndrome imprinted by maternal overnutrition.


List of Research Outputs

He M., Li E.T.S. , Harris S., Yau C.Y. and Anderson G.H., The Canadian Global Village Reality: A look at anthropo metric surrogate cut-offs and metabolic abnormalities among East-Asian, South-Asian and European descendant. , Canadian Family Physician . Canada, College of Family Physicians of Canada, 2010, 56: e174-182.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption , Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratr ol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G ., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li J

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J. , Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.


Researcher : Li J

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Repro ductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Sympo sium . 2009, 74.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor respons es in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J. , Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.


Researcher : Li L

List of Research Outputs

Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.


Researcher : Li M

List of Research Outputs

Li M. , Hong Y., Klotz M. and Gu J.D. , A comparison of primer sets for detecting 16S rRNA and hydrazine oxidoreductase genes of anaerobic ammonium-oxidi zing bacteria in marine sediments, Applied Microbiology and Biotechnology . Heidelberg, Germany, Springer, 2010, 86: 781-790.
Li M. , Yang H. and Gu J.D. , Phylogenetic diversity and axial distribution of microbes in the intestinal tract of the polychaete Neanthes glandicincta, Microbial Ecology . New York, Springer, 2009, 58: 892-902.


Researcher : Li WMM

List of Research Outputs

Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Lie PYP

List of Research Outputs

Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents bloo d-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.


Researcher : Lim BL

Project Title: High-yield GM Camelina for biofuel application
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 06/2009
Completion Date: 05/2010
Abstract:
On 30 Jan 2009, the Japan Airline (JAL) successfully conducted a test flight (Boeing 747-300) using a biofuel primarily refined from camelina. One of the four engi nes used a 50%/50% blend of biofuel and traditional kerosene fuel. The biofuel was a mixture of three second-generation biofuels: camelina (84%), jatropha (under 16%), and algae (under 1%).  No modifications to the aircraft or engine were required for the biofuel. Camelina is now a hot species in biofuel. It can grow in margin al lands with low moisture, low fertility, or saline soils. It also has low requirements for fertilizers, pesticides, and energy, which provide a better soil erosion control. http://www.montana.edu/biobased/projects/CamelinaInfo .html We have a proprietary GM technology that can speed up the growth of Arabidopsis and increased its seed yield by 40-50%. Both Camelina and Arabidopsis belong to the Brassicaceae Family and are very close to each other. It is very likely that the success of our technology in Arabidopsis will replicate in Camelina. The effect of the technology can be seen in the following links: http://hk.youtube.com/watch?v=Yq842GWKdYw http://hk.youtube.com/watch?v=8xS8iVqToK8


Project Title: Platform Technology for Yield Imp rovement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL, Phang TH
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Support Programme (Tier 3)
Start Date: 12/2009
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the patent-pending transgene. This project is important for HKU to stre ngth the patent portfolio of this platform technology before the multi-billion agrobiotechnology companies (Monsanto, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumve nt our technology by finding and patenting the genes located upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Camelina with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation bi ofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants.


Project Title: Platform Technology for Yield Improvement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 01/2010
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the patent-pending transgene. This project is important for HKU to strength the patent portfolio of this platform technology bef ore the multi-billion agrobiotechnology companies (Monsanto, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumvent our technology by finding and patenting the genes loca ted upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Camelina with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation biofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants


Project Title: Platform Technology for Yield Impr ovement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 01/2010
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the pat ent-pending transgene. This project is important for HKU to strength the patent portfolio of this platform technology before the multi-billion agrobiotechnology companies (Monsant o, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumvent our technology by finding and patenting the genes located upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Cameli na with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation biofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants


Project Title: 12th World Congress of the International Association for Plant Biotechnology Over-expression of a novel Arabidopsis phosphatase results in accelerated growth and increased seed yield
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.
Liang C., Tian J., Lam H.M., Lim B.L. , Yan X. and Liao H., Biochemical and Molecular Characterization of PvPAP3, a Novel Purple Acid Phosphatase Isolated from Common Bean Enhancing Extracellular ATP Utilization, Plant Physiology . 2009, 152: 854-865.
Lim B.L. , Leung Y.C. , Yung K.F. , Leung M.K.H. , Mah D.N.Y. , Lam J.C.K. and Hills P.R. , Conference Presentation: "Development of Biofuel Technologies and Policy", at the Initiative on Clean Energy and Environment’s Review Workshop, Shenzhen, January 8, 2010 .
Lim B.L. , TonB-Dependent Receptors in Nitrogen-Fixing Nodulating Bacteria., Microbes and Environments . 2010, 25: 67–74.
Wang X.R., Wang Y.X., Jiang T., Lim B.L. , Yan X.L. and Liao H., Overexprressing AtPAP15 enhances phosphorus efficiency in Soybean 1[W][OA] , Plant Physiology . 2009, 151: 233-240.
Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Liu H

List of Research Outputs

Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essent ial for chloroplast function., New Phytologist . 2010, 187: 83-105.


Researcher : Liu J

List of Research Outputs

Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Liu M

List of Research Outputs

Sadovy Y.J. , Liu M. and Suharti S., Gonadal development in a giant threatened reef fish, the humphead wrasse Cheilinus undulatus, and its relationship to international trade, Journal of Fish Biology . 2010, 77: 706-718.


Researcher : Lo CSC

Project Title: Promoter analysis of a pathogen-in ducible dihydroflavonol reductase gene in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 09/2009
Abstract:
Sorghum (Sorghum bicolor) is a tropical cereal best known for its unusual tolerance of hot and dry environments and its wide range of natural products (secondary metabolites) synthesized. We are interested in sorghum because it produces a unique class of flavonoid phytoalexins, the 3-deoxyanthocyanidins, as an essential component of defense mechanism against pathogen infection. These compounds are distinct from the widely distributed anthocyanidins in which they lack a C-3 hydroxyl group and they occur naturally as aglycones (Fig. 1). We have identified the 3-deoxyanthocyanidins as luteolinidin, apigeninidin, and their respective methyl ethers [1-3]. Complete in vitro toxicity to fungal pathogens occurred at concentrations less than 10 μM for each compound [1]. We demonstrated that the 3-deoxyanthocyanidin phytoalexins are significant for resistance against Colletotrichum sublineolum [4], the causal agent of anthracnose which is a major disease affecting the worldwide production of both corn and sorghum. In recent years, flavonoids such as anthocyanins have been associated with health beneficial properties, such as lowering the risks of cardiovascular diseases and cancers. Our recent studies demonstrated that the 3-deoxyanthocyanidins were more effective than their 3-hydroxylated analogs of anthocyanidins in suppressing the proliferation of two cancer cell lines [5]. The health benefits of 3-deoxyanthocyanidins to both plants and humans highlighted the importance for understandin g the regulation of their biosynthesis pathway. Flavonoid biosynthesis begins with chalcone synthase which directs the flow of carbon from the phenylpropanoid pathway to the formation of naringenin from which both anthocyanidins and 3-deoxyanthocyandins are derived (Fig. 2). The final steps in the 3-deoxyathocyanidin pathway are still unknown. Reduction and dehydroxylation reaction steps similar to those in the anthocyanidin pathway have been proposed, but without the involvement of flavanone 3-hydroxylase (F3H) which introduces the C-3 hydroxyl group in flavonoids (Fig. 2). The enzyme dihydroflavonol reductase (DFR) participates in both branch pathways leading to anthocyanidin and 3-deoxyanthocyanidin biosynthesis. Recently we demonstrated the differential expression of two DFR cDNAs (SbDFR1 and SbDFR2) in sorghum seedlings responding to differ ent stimuli (Fig.3). In response to light, etiolated seedlings accumulate anthocyanin pigments in the mesocotyl tissues. When they are inoculated with fungal pathogens, 3-deoxya nthocyanidins accumulate as phytoalexins. As shown in Fig. 3, SbDFR1 was specifically induced during light-induced anthocyanin accumulation while SbDFR2 was specifically induced during pathogen-induced 3-deoxyanthocyanidin synthesis in sorghum seedlings. Their encoded proteins are highly conserved with over 80% sequence identity. More recently, we demonstrated that both cDNAs encode functional DFR enzymes through complementation analysis in Arabidopsis DFR mutants (unpublished data). Furthermore, recombinant DFR proteins were found to accept both dihydroflavonol and flavanone substrates (unpublished data), which are the precursors for anthocyanidins and 3-deoxyanthocyanidins, respectively. Apparently the two DFR proteins have similar biochemical properties and the biosynthesis of 3-deoxyanthocyanidins following pathogen infection is mainly regulated at transcriptional level. There have been few studies on the transcriptional regulation of 3-deoxyflavonoid biosynthesis in plants. In maize, formation of phlobaphene pigments (polymers of flavan-4-ol s, which are 3-deoxyflavanols) in pericarp is controlled by the MYB transcription factor P1 which activates chalcone synthase, chalcone isomerase, and DFR genes but not F3H [6], so that the flavanones formed would not be hydroxylated at C-3. In a recent study, the sorghum the Y1 gene (a P1 homolog) was shown to be genetically linked to phlobaphene accumulation in pericarp [7]. However, the sorghum line (BTx623) which has a deletion allele of Y1 are still able to synthesize 3-deoxanthocyanidins following pathogen inoculation (our work), indicating that a different regulatory mechanism is involved during defense response. In this proposed study, we aim to identify the cis-elements located in the promoter of the pathogen-inducible SbDFR2 gene. First, we will isolate the promoter region by screening a sorghum genomic bacterial artificial chromosome (BAC) library. Sequence analysis will be performed to define the native promoter region and putative cis -elements by online computer programs. We will develop a transgenic Arabidopsis system for expression analysis of the reporter gene β-glucuronidase (GUS) driven by different 5’-truncated derivatives of the sorghum promoter to identify the region necessary and sufficient for pathogen induction. Finally we will perform DNA-protein binding assays to locate the pathogen-responsive cis-elements in the promoter. The major mechanism of differential gene expression is transcriptional regulation, which is controlled by transcription factors that bind to DNA cis-elements located in gene promoters. To underst and transcriptional regulation that leads to differential expression, genes must be experimentally linked with the corresponding transcription factors that regulate their expression. A powerful method of identifying protein-DNA interaction is the yeast one-hybrid screening system. A key to the success of such screening is the identification of cis-elements that are interacting with the transcription factors. Results from this study therefore will provide the necessary informati on for an RGC CERG application involving the identification and characterization of transcription factors that regulate the pathogen-induced biosynthesis of 3-deoxyanthocyanidins in sorghum.


Project Title: Non-targeted metabolite profiling of infected sorghum seedlings using an enhanced UPLC-TOF -MS technology platform
Investigator(s): Lo CSC, Chu IK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Completion Date: 10/2010
Abstract:
Plants are unique in the richness and diversity of their secondary metabolism, collectively resulting in more than 200,000 natural products (or secondary metabolites) with different physiological roles in their unique habitats. Natural products are increas ing popular because of their perceived benefits, such as their anti-oxidation and anti-cancer activities. Sorghum is the fifth-ranking cereal crop in the world. The plant is best known for its unusual tolerance of hot and dry environment. In addition, sorghum are previously known to produce a range of natural products including dhurrin (a cyanogenic glycoside), sorgoleones (root exudates), and 3-deoxyanthocyanidins (antifungal phytoalexins). Our laboratory is interested in the synthesis of defense-rela ted metabolites in sorghum following infection by fungal pathogens. We have demonstrated that the 3-deoxyanthocyanidins are essential for resistance against Colletotrichum sublineolum (Lo et al. 1999), the causal agent of anthrac nose which is a major disease affecting the worldwide production of both corn and sorghum. These compounds are distinct from the widely distributed anthocyanin pigments by the absence of the C-3 hydroxyl group. We have also demonstrated that the 3-deoxyanthocyanidins are more effective than the anthocyanidins in suppressing the proliferation of two cancer cell lines (Shih et al. 2007). Recently, we have reported first example of a monocot stilbene synthase gene, SbSTS1, in sorghum and the gene is highly pathogen-inducible (Yu et al. 2005). This has led to the subsequent identification of the stilbene trans-piceid in infected sorghum seedlings. Although the stilbene metabolite was found to be non-essen tial for defense, its production may be manipulated for accumulation in the sorghum grains to enhance their nutraceutical values (Yu et al. 2008). Stilbene metabolites (e.g. resveratrol) are the well-recognized health-beneficial compounds commonly found in red wine and other grape-derived products. Recent advances in mass spectrometry (MS) technologies have allowed scientists to profile metabolites in a more robust and efficient manner. Gas chromatography-MS approaches have routinely been used to profile primary metabolites such as sugars, amino acids, and organic acids. On the other hand, liquid chromatography (LC)-MS approaches have been used for the analysis of secondary metabolites in different plant systems. Over the past few years, our laboratory has implemented a number of LC-MS/MS methodologies for targeted metabolite analysis in different plant systems. In particular, we have successfully implemented the use of a hybrid quadrupole-ion trap mass spectrometer for profiling, structural elucidation, and quantificatio n of stilbene and flavonoid metabolites in infected sorghum seedlings and transgenic Arabidopsis expressing different secondary metabolic enzymes. In the SbSTS1-transgenic Arabidopsis plants, cis-piceid (a rare stilbene isoform) was identified as the major stilbene metabolite (Yu et al. 2006) and a novel resveratrol glycoside (acetylhexoside) was also detected (Lo et al. 2007). In addition to the 3-deoxyanthocyanidins and stilbenes, there are a number of pathogen-induced unknown compounds which can be detected in C. sublineolum-infected sorghum seedlings by our routine HPLC-UV analysis, some of which may represent novel compounds with potential agricultural and nutritional applications. In addition, the maize pathogen Cochliobulus heterostrophus does not infect sorghum but is also able to cause rapid and intense accumulation of 3-deoxyanthocyanidins in the plant. This non-pathogen may also induce the accumulation of unique metabolites in sorghum. Non-targeted metabolite profiling experiments will therefore be necessary in order to obtain a comprehensive picture of the phytochemical changes in the plant following challenges by different fungal pathogens. In this regard, a robust separation approach with high resolving power is extremely essential for separation of complex samples into individual co mponents. Among the various LC platforms, ultra-performance liquid chromatography (UPLC) has emerged as a high-resolution separation technology with enhanced retention time reproducibility and increased peak capacity, maximizing the number of detectable components in profiling metabolite experiments. UPLC also allows extraction to be downsized to accommodate tissues of small quantities. Different mass analyzers coupled to LC separation have also been explored in metabolomics studies, but the time-of-fli ght (TOF) mass spectrometers provide mass information with higher accuracy and precision. The accurate mass values can be used to deduce empirical formulae for candidate compounds, at the 3-5 ppm range, significantly reducing the number of possible structures with molecular masse s of a few hundred Daltons. The major objective of this exercise is to generate a list of metabolite markers for sorghum seedlings inoculated with either C. sublineolum or C. heterotrophus. The metabolite markers will be cross-examined in cultivars with different disease responses to identify the potential compound essential for disease resistance in sorghum. Some of the differentially expressed metabolites may represent novel compounds and they will need to be subject to preparative HPLC purification and NMR analysis in fu ture investigations. In addition, we will seek to implement an enhanced UPLC-TOF-MS technology platform with increased peak capacity, higher resolution, and high mass-accuracy for systematic and non-targeted identification of met abolites in the investigations of plant natural products.


Project Title: XIV International Congress on Molecular Plant-Microbe Interactions Molecular dissection of pathogen-inducible flavonoid pathway in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Further dissections of the pathogen-inducible 3-deoxyanthocyanidin biosynthesis pathway in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
The cultivation of genetically uniform crop species over large areas of farmland frequently results in severe outbreaks of diseases with huge economic losses. In addition, the use of agrochemicals for disease control often leads to pollution and elevated production costs. Better understanding of the molecular mechanism s of disease resistance is essential for providing novel approaches to improve crop performance through traditional breeding and genetic engineering. In resistant responses to attempted infections, many plants deploy an array of antimicrobial compounds to halt pathogen developmen t. These infection-induced defense compounds are called “phytoalexins” which are secondary metabolites synthesized de novo from primary metabolites. We are interested in sorghum (Sorghum bicolor) because it produces a rare class of flavonoids, the 3-deoxyanthocyanidins, as phytoalexins for successful defense against fungal infection. 3-Deoxyanthocyanidins are pigmented compound s limited to a few plant species. They are the major pigments in sinningia flowers, silk tissues of some maize (=corn) cultivars, and sorghum bran. To our knowledge, pathogen-inducible biosynthesis of 3-deoxyanthocyanidins occurs only in sorghum. Structurally, 3-deoxyanthocyani dins are very similar to the more commonly found plant pigments, anthocyanins, except for the absence of C3-hydroxylation (Fig. 1). Anthocyanins from different sources have been shown to suppress cancer cell proliferation and induce apotosis (1, 2). Recently, we demonstrated that the 3-deoxanthocyanidins are more effective than anthocyanidins in suppressing the proliferation of the human HL60 and HepG2 cancer cell lines (3). In addition, the 3-deoxyanthocyanidins are more stable to pH, temperature, and light changes than the anthocyanins (4). They have absorption maxima lower than 480 nm, which is a feature potentially useful for the replacement of artificial yellow and orange pigments. Since there is also an increasing interest in natural food coloran ts with functional properties (4), 3-deoxyanthocyanidins are likely to be a good candidate with desirable attributes useful in food and nutritional applications. The health benefits of 3-deoxyanthocyanidins to both sorghum and human highlight the importance to elucidate their route of biosynthesis. Flavonoid formation begins with a condensation reaction catalyzed by chalcone synthase (SbCHS) converting p-coumaroyl CoA and malonyl CoA into naringenin chalcone (Fig. 2), followed by isomerization to the flavanone naringenin by chalcone isomerase. It is from naringenin that the anthocyanidin and 3-deoxyanthocyanidin pathways are believed to diverge from each other (Fig. 2). The biosynthesis of anthocya nin is one of the best characterized secondary metabolic pathways in plants. Flavanone-3-hydroxylase (SbF3H) catalyzes the C-3 hydroxylation of naringenin, followed by an NADPH-dependent reduction of the C-4 carbonyl group by dihydroflavonol 4-reductase (DFR). Removal of the resulting hydroxyl group then occurs via the anthocyanidin synthase (ANS)-catalyzed reaction. In sorghum, fungal inoculation was shown to result in de novo synthesis of 3-deoxyanthocyanidins. For example, infected seedlings incorporated 14C-phenylalanine into 3-deoxyanthocyanidins within 48 h post inoculation (5). In addition, activities of the key branch-point enzymes PAL and CHS and the expressions of their respective genes were induced within 6 h of inoculation (6, 7). In our recent RGC-GRF project, we were able to identify a pathogen-inducible sorghum DFR gene (SbDFR3) and demonstrated that it encodes an enzyme with flavanon e reductase activity (Fig. 2) (manuscript in preparation). Thus, naringenin and eriodictyol are converted to the respective flavan-4-ols, the presumptive immediate precursors for 3-deoxyanthocyanidin formation (Fig. 2). On the other hand, the molecular components responsible for the conversion of flavan-4-ols to 3-deoxyanthocyan indin are still unidentified. This dehydroxylation step has been suggested to be catalyzed by an ANS enzyme similar to the one involved in anthocyanidin formation. Our recent analysis of sorghum genome revealed the presence of a single ANS-encoding gene (SbANS). However, its expression is only activated during light-induced anthocyanin pigmentation, but not during pathogen-indu ced 3-deoxyanthocyanidin biosynthesis. Apparently, an independent gene encoding similar enzyme activities is likely to be responsive to pathogen infection for the phytoalexin production. Two major classes of transcription factors, the bHLH-type R/B family and the MYB-type C1 family, are known to regulate anthocyanin biosynthesis in many plants (8). On the other hand, P is a MYB regulatory protein acting independently of R1 and C1 in maize floral tissues for the accumulation of 3-deoxyflavonoids, including 3-deoxyanthocyanidins (9-11). In sorghum, there have been few studies on the regulation of flavonoid biosynthesis. Recently, the Myb gene Y1 was reported to encode a sorghum P homolog which determines 3-deoxyanthocyanidin pigmentation in the pericarp (12). The sorghum cultivar BTx623, which was found to harbor a deletion allele of Y1, produces seeds without the accumulation of 3-deoxyanthocyanid ins (13). However, infected BTx623 plants are still able to synthesize the 3-deoxyanthocyandin phytoalexins (14), strongly suggesting that a different regulatory network is involved for the pathogen-inducible biosynthesis of 3-deoxyanthocyanidins. Over the past decade, sorghum has become a subject of plant genomics research due to its importance as a major grain crop with unusual tolerance of dry and hot environments, a biofuel crop of high and growing significance, a progenitor of the world’s most noxious weeds, and a small genome model system for many highly photosynthetic-efficient C4 cereals with complex genomes. The genome sequencing of a leading US inbred, BTx623, is now complete, providing a foundation for the discovery of beneficial genes useful for different agricultural applications (15). In this study, we will take advantage of the sorghum genomic resource to facilitate our ongoing efforts to identify novel molecular components involved in the pathogen-inducible 3-deoxyanthocyanidin biosynthesis pathway. To identify the potential candidates for the final reaction step, bioinformatics analyses will be performed to retrieve ANS-homologous sequences for gene expression analysis using our sorghum inoculation system. In addition, we will use our recently implemented iTRAQ quantitative proteomics technology to investigate the differential protein expression profiles of sorghum cultivars with and without the ability to synthesize the 3-deoxanthocyanidin phytoalexins. It is expected that the phytoalexin-deficient line is defective in some key proteins, potentially enzymes and/or regulatory proteins, required for the biosynthesis pathway. Fina lly, we will employ our well-developed LC-MS/MS platform to examine the differential metabolite profiles of the two sorghum cultivars mentioned above. As the phytoalexin-deficient cultivar is likely to accumulate some intermediates of the 3-deoxyanthocyanidin pathway, their identification will further facilitate our searches for the unknown enzymes/genes along the pathway.


List of Research Outputs

Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen- inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Du Y. and Lo C.S.C. , Molecular characterizatiom of a flavone synthase gene in sorghum, Plant Biology 2009, Honolulu, Hawaii . 2009.
Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxy anthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essential for chloroplast function., New Phytologist . 2010, 187: 83-105.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.
Lo C.S.C. , Senior Editor, Physiological and Molecular Plant Pathology . Elsevier, 2010.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.


Researcher : Lui WY

Project Title: Function of CLMP in rat testis and its regulation
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
The BTB situated between adjacent Sertoli cells physically divides the seminferous epithelium into the basal and adluminal compartments. The BTB not only maintains cell polarity, it also segregates the post-meiotic germ cell development from the systemic circulation to avoid autoimmune response [1, 3]. However, this intact barrier must disassemble at stage VIII of the seminiferous cycle to allow pre-leptotene and leptotene spermatocytes residing outside the BTB (the basal co mpartment) to migrate across the barrier and enter the adluminal compartment. Recent studies have indicated that Coxsackie and Adenovirus Receptor-Like Membrane Protein (CLMP) is a novel member of the Cortical Thymocyte Marker in Xenopus (CTX) family and a new component of epithe lial tight junction [6]. Exogenously expressed CLMP in polarized MDCK cells has shown that CLMP is restricted to the cell-cell interface and co-localized with ZO-1, a tight junction marker [6]. A significant increase in transepith elial electrical resistance (TER) has been found in cultured CLMP-expressing MDCK cells when compared to cells not expressing CLMP. CLMP has been found to associate with occludin in caco-2 cells and forced expression of CLMP in CHO cells induces cell aggregation [6]. Our recent findings have showed that testis expresses CLMP and CLMP is co-localized with occludin at the BTB [2]. We have also studied the transcriptional regulation of CLMP in Sertoli cells. It has noted that the expression of CLMP is mediated via the interaction of GATA and the Kruppel family proteins, KLF4 and Sp1. Moreover, our preliminary data showed that CLMP could be down-regulated by tumor necrosis factor alpha (TNF-alpha) via alterati on of its mRNA turnover. In our laboratory in the past years, a series of in vitro and in vivo studies have clearly demonstrated that TNF alpha and TGF-beta3 are key cytokines that perturb BTB and exerts potent negative effect in the expression of several TJ proteins in the testis such as JAM-A, CAR and occludin [1, 4, 5, 7]. These results taken together suggest that CLMP is a novel TJ protein that is regulated by TNF alpha and TGF-beta and is also involved in BTB dynamics. The P.I. seeks to characterize the role of Coxsackie and Adenovirus Receptor-Like Membrane Protein (CLMP) in the testis. Specifically, the P.I. will unravel (i) the functional role of CLMP in the testis and (ii) the effects of germ cells, cytokines (TNF-alpha and TGF-beta 3) and hormones (FSH and testosterone) on the expression of CLMP in Sertoli cells and in the testis. 1. Lui WY* and Cheng CY* (2007) Regulation of cell junction dynamics by cytokines in the testis – a molecular and biochemical perspective. Cytokine and Growth Factor Reviews 18:299-311 *Corresponding authors 2. Sze KL, Lee WM, Lui WY* (2007) Expression of CLMP, a novel tight junction protein, is mediated via the interaction of GATA with the Kruppel Family proteins, KLF4 and Sp1, in mouse testis. Journal of Cellular Physiology (in press) 3. Lui WY and Lee WM (2006) Regulation of junction dynamics in the testis – Transcriptional and post-translational regulations of cell junction proteins. Molecular and Cellular En docrinology 250:25-35 4. Li MW, Xia W, Mruk D, Wang CQ, Yan HH, Siu MK, Lui WY, Lee WM, Cheng CY (2006) Tumor necrosis factor alpha reversibly disrupts the blood-testis barrier and impairs Sertoli-germ cell adhesion in the semini ferous epithelium of adult rat testis. Journal of Endocrinology 190:313-329 5. Wong CH, Mruk DD, Lui WY, Cheng CY (2004) Regulation of the blood-testis barrier dynamics in the testis: an in vivo study. Journal of Cell Science 117:783-798 6. Raschperger E, Engstrom U, Pettersson RF, Fuxe J (2004) CLMP, a novel member of the CTX family and a new component of epithelial tight junctions. Journal of Biological Chemistry 279:796-804 7. Lui WY, Wong CH, Mruk DD, Cheng CY (2003) TGF-beta 3 regulates the blood-testis barrier dynamics via the p38 mitogen activated protein (MAP) kinase pathway: An in vivo study. Endocrinology 144:1139-1142


Project Title: Unraveling the mechanisms on cytokine-mediated regulation of Junctional Adhesion Molecules (JAM) in the testis
Investigator(s): Lui WY, Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Abstract:
(1) Identification of the signaling pathway(s) in cytokine-mediated transcriptional regulation of JAMs in testicular cells; (2) Characterization of the cytokine-mediated post-transcriptional regulation of JAM transcripts; (3) Characterization of cytokine-mediated post-translational modification of JAM proteins.


Project Title: Role of nectin-like molecules (necls) and its regulation in the testis
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2009
Abstract:
Background: Importance of junction restructuring in spermatogenesis Dynamic restructuring of adherens junctions (AJ) between Sertoli and germ cells is a crucial event for germ cell development. Migration of developing germ cells across the seminiferous epithelium requires timely disassembly and reassembly of AJs, so that germ cells are able to migrate towards the tubular lumen for further development, and at the same time they must remain physically attach onto Sertoli cells for nutritional and structural supports. The timely disassembly of AJs between Sertoli cells and mature spermatids is also important to allow the release of spermatozoa at spermiation. Any interruption of AJ restructuring could either lead to premature release of germ cells or blockage of germ cell migration along the epithelium, resulting in infertility. Therefore, it is apparent that precise control of AJ restructuring in the epithelium is crucial for the completion of germ cell development (1, 2). Biology and structural components of adherens junctions in the epithelium Actin-based cell-cell AJs are extensively localiz ed at the Sertoli cell/germ cell interface and between adjacent Sertoli cells. Ectoplasmic specialization (ES) is a testis-specific AJ, namely basal ES and apical ES. Basal ES is limited to adjacent Sertoli cells at the blood-testis barrier while apical ES is restricted to Sertoli cells and elongating spermatids (step 8 and beyond). Basal ES is constituted by several AJ proteins such as cadherin, nectin-2, Junctional Adhesion Molecule-B (JAM-B). However, four specific interlocking protein complexes, namely nectin-2/nectin-3, β1-integrin/laminin, JAM-B/JAM-C and nectin-like molecule 2 (necl-2)/necl-5 interlocks, are found at the apical ES (for review, see 2). These multiple interactions of junction proteins in the seminiferous epithelium ensure a close interaction of Sertoli and germ cells, and avoid detachment of premature germ cells from Sertoli cells during translocation. Nectin-like molecules (necls) and its members in the testis Nectin-like molecules are immunoglobulin (Ig)-like adhesion molecule that has three extracellular Ig domains, one transmembrane domain and a cytoplasmic tail containing a type II PDZ-binding domain. The necl family comprises five members and they are ubiquitously expressed. Like nectins, necls mediates both homophilic and heterophilic cell adhesion in Ca2+-independent manner (3). Other than its function on cell-cell adhesion, recent studies have shown that necls are involved in other cellular activities, including cell polarization, differentiat ion, movement and survival (4, 5). Three necl members (necl-2, -3, -5) are expressed in the testis (6-8). In the mouse testis, necl-2 is expressed exclusively on germ cells (6). Necl-2 is found in spermatogenic cells from intermediate spermatogonia to pachytene spermatocytes and steps 7-16 spermatids (6). Necl-2-based cell adhesion is found to be essential for retaining spermatocytes and elongating spermatids in the Sertoli cells for their maturation and the translocation of mature spermatids to the adluminal surface for release since three separate gene knockout studies have shown that male mice lacking necl-2 are infertile (6, 9, 10). Recent studies have shown that necl-2 can form a ternary complex with JAM-C via interaction with PAR3 in elongating and elongated spermatids (7). For necl-5, it is expressed in Sertoli cells. Co-immprecipitation studies have been shown that necl-5 is an interacting partner of necl-2 (11), suggesting that necl-2/necl-5 protein complex is one of the essential interlocking protein complexes to mediate the interaction between spermatogenic cells and Sertoli cells for germ cell development. For necl-3, a high level of necl-3 mRNA was detected in the testis. However, the localization and its function in the testis remain enigmatic (8). Cytokines and junction restructuring There are accumulating evidences showing that TGF-βs (TGF-β2 and TGF-β3) and TNFα are actively involved in junction restructuring in the seminiferous epithelium, thus facilitating the movement of developing germ cells. TGF-β3 is a crucial cytokine that modulates the disassembly of blood-testis barrier (constituted by basal ES and tight junctions), apical ES and AJ by down-regulating the expression of integral membrane proteins such as occludin and N-cadherin via the activation of different signaling pathways such as p38 and ERK pathways (12-15). Studies from our laboratory have demonstrated that TGF-β2 reduces JAM-B protein level. TGF-β2 exerts its negative regulatory effects on JAM-B via activating Smad proteins. Activate d Smads compete against and displace Sp1 proteins from the TGIF motif of JAM-B promoter, resulting in JAM-B repression (16). A recent study has shown that TGF-β2 accelerates the internalization of integral membrane proteins such as JAM-A and occludin via clathrin-coated pit and targets them into late endosomes for degradation by lysosomes, thereby reducing the level of proteins and leading to the disassembly of cell junctions (17) . Apart from TGF-β, TNFα is also a potent cytokine in regulating junction restructuring. TNFα can downregulate occludin, ZO-1, CLMP protein levels in the testis (18). We have demonstrated that TNFα acts on the CLMP mRNA transcript and destabilize the transcript by promoting the binding of tristetraprolin (TTP) at the 3’UTR region under the activation of JNK pathway (19). Besides, TNFα is capable to induce the disorganization of actin bundles and the cisternae of ER at the apical ES, leading to the release of premature spermatids (18). Objectives: This proposal aims to investigate the role of necls and its regulation in the testis. 1. To identify the interacting partners of necls in the testis 2. To investigate the effects of cytokines on the expression of necls in the testis 3. To identify the localization of necl-3 in the testis References: 1. Lui WY, Mruk D, Lee WM, Cheng CY (2003) J Androl 24:1-14 2. Lui WY and Cheng CY (2007) Cytokine and Growth Factor Reviews 18:299-311 3. Fujita E, Soyama A, Momoi T (2003) Exp Cell Res 2003 287:57-66 4. Takai Y, Irie K, Shimizu K, Sakisaks T, Ikeda W (2003) Cancer Sci 94:655-667 5. Takai Y, Miyoshi, Ikeda W, Ogita H (2008) Nat Rev 9:603-615 6. Fujita E, Kouroku Y, Ozeki S, Tanabe Y, Toyama Y, et al. (2006) Mol Cell Biol 26:718-726 7. Fujita E, Tanabe Y, Hirose T, Aurrand-Lions M, Kasahara T, et al. (2007) Am J Pathol 171:1800-1810 8. Pellissier F, Gerber A, Bauer C, Ballivet M, Ossipow V (2007) BMC Neurosci 8:90-107 9. van der Weyden L, Arends MJ, Chausiaux OE, Ellis PJ, et al. (2006) Mol Cell Biol 26:3595-3609 10. Yamada D, Yoshida M, Williams YN, Fukami T, Kikuchi S, et al. (2006) Mol Cell Biol 26:3610-3624 11. Wakayama T, Sai Y, Ito A, Kato Y, Kurobo M, et al. (2007) Biol Reprod 76:1081-1090 12. Lui WY, Lee WM, Cheng CY (2001) Endocrinology 142:1865-1877 13. Lui WY, Lee WM, Cheng CY (2003) Biol Reprod 68:1597-1612 14. Xia W, Cheng CY (2005) Dev Biol 280:321-43 15. Xia W, Mruk DD, Lee WM, Cheng CY (2006) J Biol Chem 281:16799-813 16. Wang Y and Lui WY (2008) Endocrinology (accepted) 17. Yan HH, Mruk DD, Lee WM, Cheng CY. (2008) FASEB J 22:1945-1959 18. Li MW, Xia W, Mruk D, Wang CQ, et al. (2006) J Endocrinol 190:313-329 19. Sze KL, Lui WY, Lee WM (2008) Biochem J 410:575-583


Project Title: 34th FEBS Congress Itch interacts with the pre-initiation complex for gene transcription
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Outstanding Young Researcher Award 2008-2009
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Young Researcher Award
Start Date: 12/2009
Abstract:
The Awards are intended to recognize, reward, and promote exceptional research accomplishments of academic and research staff.


Project Title: Coxsackie and adenovirus receptor-like membrane protein (CLMP) is a new tight junction protein in the testis: its role and regulations
Investigator(s): Lui WY, Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To investigate the role of CLMP in BTB dynamic s; 2) To identify CLMP-associating partners in the cytosol; 3) To assess the effect of cytokine on the expression of CLMP in Sertoli cells and in the testis.


Project Title: Unraveling the role of Ets related molecule (ERM) in the testis
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
Background: Cell junctions in the seminiferous epithelium and their physiological significance in spermatogenesis Different types of cell junctions are found in the seminiferous epithelium. Apart from the tight junctions (TJ) that is localized at the blood-test is barrier (BTB), anchoring junctions are also found at the BTB and the Sertoli-germ cell interface in the seminiferous epithelium (1). These junctions are adherens junctions (AJ) including basal and apical ectoplasmic specializations (ES). ES is an actin-based testis-specific hybrid AJ type which is confined to the region between the plasma membrane of two adjacent Sertoli cells. Basal ES is limited to the BTB, coexisting with TJ, whereas apical ES is found between Sertoli cells and elongating/elongated spermatids (step 8 and beyond in adult rat testes). Knockout studies have shown that various TJ proteins including occludin, junctional adhesion molecule-A (JAM-A) claudin-11 and ZO-2 are essential for spermatogenesis. Knockout of these TJ proteins result in male infertility (2-4). Like TJ proteins, knockout of AJ proteins such as nectin-2, nectin-3 or JAM-C in mice cause severe disruption in spermatogenesis and all male mice are sterile (5-7). These results apparently illustrated the functional significance of junction proteins in spermatogenesis. Formation of the intact BTB between adjacent Sertoli cells and dynamic restructuring of cell junc tions (such as ES) between Sertoli and germ cells are crucial events for germ cell development (1). The formation of the BTB allows physical segregation of meiotic germ cells from the systemic circulation that avoids autoimmune response. During spermatogenesis, developing germ cel ls must migrate across the seminiferous epithelium towards the tubular lumen for further development, and at the same time they must remain physically attach onto Sertoli cells for nutritional and structural supports, such movement requires precise disassembly and reassembly of cell junctions. In addition, the timely disassembly of ES between Sertoli cells and mature spermatids is also important to allow the release of spermatozoa at spermiation (1). Any interruption of junction restructuring could either lead to premature release of germ cells or blockage of germ cell migration along the epithelium, resulting in infertility. Therefore, it is apparent that the formation of the BTB and timely junction restr ucturing in the epithelium are crucial for the completion of germ cell development. Infertility in male Ets related molecule (ERM) knockout mice Male mice with targeted disruption of Ets related molecule (ERM) displayed testicular atrophy with tubules devoid of germ cells (8). Although ERM is a transcription factor exclusively expressed in Sertoli cells, changes in gene expression levels are not restricted to Sertoli cells. In fact, a plethora of genes in spermatogonial germ cells are found to be altered in their expressions in the knockout mice (8). It is believed that knockout of ERM alters the gene expression in Sertoli cells, which results in significant change in seminiferous epithelial micr oenvironment and halts germ cell development. A list of genes in Sertoli cells has been found to be down-regulated (9- to 25-fold reduction) in ERM knockout mice and they are stromal cell-derived factor (SDF-1), chemokine ligand 5 (CXCL5), chemokine ligand 7 (CCL7) and matri x metalloproteinase 12 (MMP-12) (8). Based on the studies from other epithelial cells, it is known that chemokines and MMPs are crucial molecules that regulate the barrier function. For instance, chemokine, CCL2 induces TJ disassembly in blood-brain barrier by inducing internaliza tion of claudin and occludin (9), whereas MMP promotes extracellular matrix degradation and resulting in junction disruption (10). However, it remains unknown whether the knockout of ERM gene affects the integrity of the blood-testis barrier and cell junction restructuring in the testis and whether ERM acts directly to control the gene transcription of junction proteins. Regulation of junction dynamics via transcriptional and post-translational modifications Timely regulation of the expression of different junction proteins in the testis is crucial during spermatogenesis. Both transcriptional and post-translational modifications are major approaches to exhibit temporal and spatial expression of junction proteins in the testis (1, 11). Studies from our laboratory have demonstrated that cytokine exerts its negative regulatory effects on JAM-B transcription via activating Smad proteins (12). Activated Smads compete against and displace Sp1 proteins from the TGIF motif of JAM-B promoter, resulting in JAM-B repression. A recent study has shown that cyto kine trigger the internalization of integral membrane proteins such as JAM-A and occludin via clathrin-coated pit and targets them into late endosomes for degradation by lysosomes (13), thereby reducing the level of proteins and leading to the disassembly of the BTB. Objectives: This proposal aims to investigate the role of ERM on junction restructuring in the testis 1. To generate two Sertoli cell cell lines, (1) stably-expressing ERM in TM4 cells; and (2) stably-expressing ERM shRNA in MSC-1 cells 2. To assess the effect of ERM on the expression of junction proteins Reference: 1. Lui WY and Cheng CY (2007) Cytokine and Growth Factor Reviews 18:299-311 2. Saitou M, Furuse M, Sasaki H, Schulzke JD, Fromm M, Takano H, Noda T and Tsukita S (2000) Mol Biol Cell 11:4131-414 2 3. Xu J, Anuar F, Ali SM, Ng MY, Phua DC and Hunziker W (2009) Mol Biol Cell 20:4268-4277 4. Gow A, Southwood CM, Li JS, Pariali M, Riordan GP, Brodie SE, Danias J, Bronstein JM, Kachar B and Lazzarini RA (1999) Cell 99:649-659 5. Mueller S, Rosenquist TA, Takai Y, Bronson RA and Wimmer E (2003) Biol Reprod 69:1330-1340 6. Ozaki-Kuroda K, Nakanishi H, Ohta H, Tanaka H, Kurih ara H, Mueller S, Irie K, Ikeda W, Sakai T, Wimmer E, Nishimune Y and Takai Y (2002) Curr Biol 12:1145-1150 7. Gliki G, Ebnet K, Aurrand-Lions M, Imhof BA and Adams RH (2004) Nature 431:320-324 8. Chen C, Ouyang W, Grigura V, Zhou Q, Carnes K, Lim H, Zhao GQ, Arber S, Kurpios N, Murphy TL, Cheng AM, Hassell JA, Chandrashekar V, Hofmann MC, Hess RA and Murphy KM (2005) Nature 436:1030-1034 9. Stamatovic SM, Keep RF, Wang MM, Jankovic I and Andjelkovic AV (2009) J Biol Chem 284:19053-19066 10. Klessner JL, Desai BV, Amargo EV, Getsios S and Green KJ (200 9) Mol Biol Cell 20:328-337 11. Lui WY and Lee WM (2008) Front Biosci 13:6775-6786 12. Wang Y and Lui WY (2009) Endocrinology 150:2404-2012 13. Yan HH, Mruk DD, Lee WM and Cheng CY. (2008) FASEB J 22:1945-1959


List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Lui W.Y. , Editorial Board Member, Spermatogenesis . 2010.
Lui W.Y. , HKU Outstanding Young Researcher Award, The University of Hong Kong . 2010.
Lui W.Y. and Tam C.Y. , Itch interacts with the pre-initiation complex for gene transcription, The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Lui W.Y. and Lee W.W.M. , Molecular mechanisms by which hormones and cytokines regulate cell junction dynamics in the testis, Journal of Molecular Endocrinology . 2009, 43: 43-51.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness, The 35th FEBS Congress Molecules of LIfe. June 26- July 1, 2010. . 2010.


Researcher : Ma CY

Project Title: Analysis of chemically modified non-starch polysaccharides by Raman spectroscopy
Investigator(s): Ma CY
Department: Botany
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To apply the technique of Raman spectroscopy for determining degrees of chemical modification in proteins, and extend the technique to study modified non-starch polysaccharides.


Project Title: Institute of Food Technologists Annual Conference 2009 Conformational study of SPI treated with ultrasound
Investigator(s): Ma CY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2009
Abstract:
N/A


Project Title: 15th European Carbohydrate Sympos ium (eurocarb 15) Raman and FTIR spectroscopic study of sulfated non-starch polysaccharides
Investigator(s): Ma CY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A




Researcher : Ma J

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J. , Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.


Researcher : Ma J

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J. , Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.


Researcher : Mruk DD

List of Research Outputs

Cheng C.Y. , Wong E.W.P. , Yan H.H.N. and Mruk D.D. , Regulation of spermatogenesis in the microenvironment of the seminiferous epithelium: new insights and advances, Mol Cell Endocrinol . 2010, 315: 49-56.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biolo gy. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents blood-testi s barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Ng CY

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.


Researcher : Ng SM

Project Title: Molecular cloning and functional characterization of the human cell cycle related kinase-interacting proteins
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Small Project Funding
Start Date: 12/2005
Abstract:
1. To clone the genes encoding the proteins that specifically interact with CCRK in a yeast two-hybrid screening. 2. To elucidate the functional roles of the CCRK-interacting proteins in glioblastoma carcinogenesis.


Project Title: The role of chemokine CC-motif receptor-like 2 (CCRL2) in colon cancer carcinogenesis
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2008
Abstract:
Colorectal cancer or colon cancer is the third most common cancer worldwide and it ranks only after breast and lung cancers in females, and prostate and lung cancers in males (Jemal et al., 2004). In Hong Kong, the incidence of CRC is increasing rapidly and it has become the second most common cancer with more than 3,500 new patients diagnosed every year (Hong Kong Cancer Registry, 2004). Compared with other parts of the world, Hong Kong has more colon cancer patients under 40 years old (Yuen et al., 1997). Therefore, understanding the pathogenesis of colon cancer and identifying new molecular targets are critical for establishing novel therapeutic and diagnostic strategies against this potentially fatal disease. It has been estimated up to 20% of colon cancer cases are resulting from chronic intestinal inflammation. This is supported by the findings that inflammatory bowel diseases (IBD) like ulcerative colitis and Crohn’s disease, markedly increase the risk of colon cancer (Klamfer, 2008). Recently, it has been demonstrated that signals which promote inflammation like, nitric oxide (Ying et al., 2007), interleukin 22 (Ziesche et al., 2007), and STAT 3 (Klampfer, 2008) are upregulated in colon cancer cells. Moreover, Kim et al. showed that expression of CXCR4, a well-characterized chemokine receptor for T cells, is associated with reduced overall survival and increased risk for recurrence and liver metastasis in colon cancer patients (Kim et al., 2005). Therefore, there is inc reasing evidence that chemokine receptors, which transduce signals for inflammation or the recruitment of immune effector cells, may initiate the carcinogenesis of colon cancer. Chemokines are small proteins (~ 8-10 kD) that regulate cell migration. Cells that are attracted by chemokines follow a signal of increasing chemokine concentration towards the source. Currently, there are more than 50 known chemokines and 18 chemoki ne receptors which play crucial roles in many important cellular functions including leukocyte recruitment, angiogenesis, and inflammation (Proudfoot et al., 2002). Chemokine CC-motif receptor-like 2 (CCRL2) (also known as human chemokine receptor (HCR), CRAM, or CKRX) is a putative 7-transmembrane G protein-coupled chemokine receptor (Neote et al., 1993; Fan et al., 1998). The CCRL2 gene is located on chromosome 3p21, a locus within the main cluster of CC-chemokine receptor genes (Maho et al., 1999). The CCRL2 receptor was first isolated in a polymorphonuclear neutrophil (PMN) cDNA library (Fan et al., 1998) and is expressed on virtually all hemopoietic cells such as monocytes, T cells, dentritic cells, natural killer cells, and CD34+ progenitor cell s (Patel et al., 2001; Migeotte et al., 2002), suggesting that this receptor is instrumental for cell-mediated immune responses and local inflammation. However, the role of CCRL2 in human cancers has never been elucidated. The objective of this project is to explore the potential role of CCRL2 in colon cancer carcinogenesis. We have obtained 12 local colon cancer tissue samples and their adjacent normal tissues and analyzed the expression profiles of CCRL2 using semi-quantitative RT-PCR. We found that CCRL2 mRNA expression was elevated in 6 out of 12 (50%) of colon cancer tissues by more than 1.5-fold (Fig. 1A, B). Moreover, expression of CCRL2 was also detected in both LoVo and DLD1 human colon cancer cell lines (Fig. 1C). Therefore, we hypothesized that overexpression of CCRL2 may induce chronic intestinal inflammation and subsequently initiate carcinogenesis in colon cancer patients. Results obtained from this study will provide new insights on the role of this chemokine receptor in colon cancer carcinogenesis.


Project Title: Identification and characterization of chemotherapeutic drugs targeting cancer stem cells
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Abstract:
Cancer cells within a tumor population often exhibit distinct proliferative and differentiation capacities, a phenomenon known as tumor heterogeneity. Early studies of spontaneous mouse leukaemias and lymphomas showed that the frequency of tumor-propagating cells ranged from 1% to 80-90% of the cells (Hewitt, 1958; Hamburger and Salmon, 1977). The mechanisms underlying tumor heterogeneity remain elusive, but at least two models have been put forward to explain the differences in the growing and regenerating capacities observed in cancer, namely the clonal evolution model (Nowell, 1976) and cancer stem cell model (Campbell, 2007). In the clonal evolution model, all undifferentiated cells have similar tumorigenicity and a dominant population of proliferating cells drives tumorigenesis. By contrast, the cancer stem cell model proposes that a subset of cancer cells, referred to as cancer stem cells, is responsible for sustaining tumor growth. Cancer stem cells are considered as a distinct group of ste m cells because they share important characteristics with normal stem cells. They have the abilities of self-renewal, generating additional cancer stem cells, and differentiating into phenotypically diverse cancer cells with lower proliferative potential. Cancer stem cells have been characterized in human acute myeloid leukaemia, breast cancer and brain cancer and surface markers have been identified in these cancer types. For example, in human breast cancer, cancer stem cells were found to express CD44 but little or no CD24 (CD44 +CD24-/low) and have enriched tumor-initiating capacity; as few as 200 CD44+ CD24-/low cells were able consistently form tumors (Al-Hajj et al., 2003). In brain cancer, cancer stem cells were found to be those which express the human neural stem cell marker CD133 (CD133+), and they were accounted for almost all in vitro proliferat ive capacity (Singh et al., 2003). Collectively, these findings suggest that cancer stem cells play a crucial role in tumorigenesis and elimination of cancer stem cells is important for providing long-term disease-free survival in cancer patients. Eradication of cancer stem cells is still a major challenge for scientists mainly because they have stronger resistance to radiother apy and chemotherapy than ordinary cancer cells. This resistance may be attributed to better initiation of DNA damage response and overexpression of drug-resistance associated proteins within cancer stem cells (Pardal and Morrison , 2003). Because cancer stem cells lead to high tumorigenic potential and develop strong resistance to radio- and chemo-therapy, they may play a pivotal role in initiating the tumor recurrence. Thus, discovery of novel chemotherap eutic drugs which effectively or specifically target cancer stem cells are urgently needed. Gold-containing compounds have been shown to possess strong anti-tumor activities (Cagnoli et al., 1998; Marcon et al., 2002). However, compound containing gold in the +III oxidation state tend to be reduced in vivo to gold(I) and metal lic gold as the intracellular environment is generally reducing (Tiekink, 2002). In collaboration with Prof. C. M. Che at the Department of Chemistry, we have recently synthesized a series of gold(III) meso-tetraporphyrins that are stable at physiological conditions (Che et al., 2003). The porphyrins ligands in these compounds stabilize the gold(III) center and carry it to their cellular targets. Their cytotoxicity is approximatel y 100-fold higher than that of cisplatin, a commonly used chemotherapeutic drug, in several human cancer cell lines (Che et al., 2003). Among these gold-containing compounds, we have previously demonstrated that gold (III) meso-tetraarylporphyrin 1a (gold-1a) exhibits strong anti-tumor activity in hepatocellular carcinoma (HCC) (Lum et al., 2006). We also tested the anti-tumo r effect of gold-1a in other cancer types including nasopharyngeal carcinoma (NPC) and melanoma. In agreement with the findings in HCC, gold-1a also exhibits potent cancer-killing , anti-metastatic, and antiangiogenic actions in mice bearing NPC (Fig. 1). Therefore, we hypothesize that gold-1a may mediate its anti-cancer effects by targeting cancer stem cells and thereby significantly inhibiting tumor growth, angiogenesis, and metastasis. The primary goal of this project is to evaluate the chemocytotoxi c effects of gold-1a, the second-generation gold(III) meso-tetraarylporphyrins (synthesized based on the structure of gold-1a), and other chemotherapeutic drugs (e.g. cisplatin and dacarbazine) on cancer stem cells. We will use the human NPC C666-1 cell line and human melanoma B16 cell line as our cell models because we have already shown previously that gold-1a potently inhibits the growth and/or metastasis of C666-1 cells and B16 cells in vivo (Fig. 1). The specific aims of this project are: 1. To examine the effects of gold-1a, the second generation gold-1a, and other chemotherapeutic drugs on the expression of common stem cell markers in human NPC C666-1 and human melanoma B16 cell lines. 2. To determine the cytotoxic effects of gold-1a, the second-generation gold-1a, and other chemotherapeutic drugs on the cancer stem cells in vitro. References: Please refer to Section VII.


Project Title: Development of novel nanopolymers for cancer gene therapy
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 03/2009
Abstract:
Gene therapy is being developed as an alternative means of medical intervention for cancer and a variety of disorders (reviewed in 1, and references therein). Viral and non-viral vectors are the two principal gene delivery methods for gene therapy. Although a number of viral vectors such as adenovirus (Adv), adeno-associated virus (AAV), and lentivirus have been proposed, there are still concerns about their safety, immunogencity, and efficacy for therapeutic applications in humans (reviewed in 2). Therefore, non-viral gene delivery systems, which are based upon polymer/DNA complexes, are attracting increasing attention owing to their ease of structural modifications and potential in avoiding the problems associated with viral vectors (reviewed in 3). An ideal polymer-based gene delivery vehicle should be bio-absorbable, non-toxic, non-immunogenic, stable, and able to access target cells after administration . Among several non-viral vectors that are currently in use, polyethylenimine (PEI), a polycationic copolymer, has shown good transfection efficiency both in vitro and in vivo (reviewed in 4). PEI has been used in a diversity of processes for many years. The basic unit of PEI consists of a backbone of two carbons followed by on e nitrogen atom. PEI comes in two forms: linear and branched. The branched form is produced by cationic copolymerization from ethylenimine (aziridine) monomers via a chain-growth mechanism, with the branched sites arising from specific interactions between two growing copolymer molecules. Depending on its molecular weight, structure and dosages, PEI can be toxic to certain cells (reviewed in 5-7). It has been reported that branched PEIs with a molecular weight (MW) of 25,000 or greater display relatively high cytotoxicity, possib ly because of the formation of large aggregates on the cell surface. Low molecular weight PEIs ( <1,800) show much less toxicity, but have very low transfection efficiency. Cyclodextrins (CyDs) are cyclic (alpha-1,4)-linked oligosaccharides of alpha-D- glucopyranose containing a hydrophobic central cavity and hydrophilic outer surface. The most common CyDs are alpha-, beta- and gamma-CyDs, which are composed of six, seven, and eight D-glucopyranose units, respectively. It has be en well documented that CyDs lack toxicity and immunogencity, and they are able to form inclusion complexes with a variety of guest molecules both in solution and in solid states. Although CyDs themselves are not effective gene carriers, they can act as a viral dispersant by enhancing both viral binding and internalization, result ing in an increase in adenoviral transduction in human colon adenocarcinoma Caco-2 cells. CyDs can disrupt biological membranes by forming complexes with phospholipids and cholesterols, which can assist the cellular uptake of polyamidoamine dendrimer/DNA particles and intracellula r trafficking of DNA molecules. The major limitations of viral vectors as tools for gene therapy are the biosafety concerns and difficulties in preparing sufficient quantities of the viruses for clinical trials and future clinical use. In order to overcome these drawbacks, our team is focusing on developing nanoplymer for gene delivery. We have already formed a collaboration with Prof. Guping Tang at Zhejiang University on the development of novel nanopolymers as gene delivery system for the treatment of glioblastoma and melanoma (selected refs. 8-14). Recently, we have jointly characterized one of the most promising nanopolymers which has high effic iency and low toxicity (patent and manuscript in preparation). This nanopolymer consists of beta-cyclodextrin (beta-CyD) as the cross-linker for connecting low molecular weight polyethylenimine (PEI). We have further improved th e gene targeting efficiency of beta-CyD-PEI by conjugating it with folic acid (CyD-PEI-FA) (Fig. 1). The resulting polymer has no detectable toxicity and exhibits high transduction efficiency comparable to that of leading commercial transfection reagents (Figs. 2 and 3). These findings have laid down a solid foundation for the further developing CyD-PEI-FA and other novel nano-bi opolymers. The purpose of this research is to develop novel and highly efficient nanopolymers as gene delivery systems for cancer gene therapy. The specific aims of this proje ct are: 1. To characterize the 3-dimensional structure, toxicity and the DNA binding affinity of CyD-PEI-FA / plasmid DNA complex in vitro in cell culture systems. 2. To determine the tumor targeting ability, tissue distribution , gene expression level, and toxicity of CyD-PEI-FA / plasmid DNA complex in vivo in mice. 3. To determine the therapeutic efficacy of CyD-PEI-FA / plasmid expressing interleukin 2 (pIL2) for the treament of melanoma in vivo in mice. References: 1. Curiel, DT.; Gerritsen, Winald R.; Krul, Mark R. L. Progress in cancer gene therapy. Cancer Gene Therapy (2000), 7(8), 1197-1199 . 2. El-Aneed, Anas. An overview of current delivery systems in cancer gene therapy. Journal of Controlled Release (2004), 94(1), 1-14. 3. Vasir, Jaspreet K.; Labhasetwar, Vinod. Polymeric nanoparticles for gene delivery. Expert Opinion on Drug Delivery (2006), 3(3), 325-344. 4. Lungwitz, U.; Breunig, M.; Blunk, T.; Goepferich, A. Polyethylenimine-based non-viral gene delivery systems. European Journal of Pharmaceutics and Biopharmaceutics (2005), 60(2), 247-266. 5. Pietersz, Geoffrey A.; Tang, Choon-Kit; Apostolopoulos, Vasso. Structure and design of polycationic carriers for gene delivery. Mini-Reviews in Medicinal Chemistry (2006), 6(12), 1285-1298. 6. Hunter, A. Christy. Molecular hurdles in polyfectin design and mechanistic background to polycation induced cytotoxicity. Advanced Drug De livery Reviews (2006), 58(14), 1523-1531. 7. Pack, Daniel W.; Hoffman, Allan S.; Pun, Suzie; Stayton, Patrick S. Design and development of polymers for gene delivery. Nature Reviews Drug Discovery (2005), 4(7), 581-593. 8. Shilei, Tang Guping, Gao Shujun, Ma Yuexia, Liu Beih ui, Li Ying, Zhen Jieming, Ng Yee Kong, Kam Leong and Shu Wang. Repeared intrathecal administration of plasmid DNA complexed with polyethylene glycol-grafted polyethlenimine for prolonged transgene expression in the spinal cord. Gene Therapy. 2003;10:1179-1188. 9. Tang GP, Zeng JM, Gao SJ, Ma YX, Shi L, Li Y, Too H-P and Wang S. Polyethyene glycol-grafted polyetylenimine for improved CNS gene transfer: Effects of PEGylation extent. Biomaterials. 2003;24:2351-236218. 10. Y Li, J Wang, C Lee, C Y Wang, S J Gao, G.P.Tang, Y X Ma, Boon Soon, C T Lim, H Yu, H Q Mao, KW Leong and S Wang CNS gene transfer facilitated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes. Gene Therapy. 2004;11:109-114 11. G.P.Tang, Z.Yang and J.Yan A. A new biodegradable poly-amino acid: α,β-poly[(N-hydrox ypropyl/aminoethyl)-DL-asppartami A potential non-viral vector for gene delivery. Drug Delivery. 2005;12:89-9. 12. Huanghong liang, Guping Tang, Qingqing Wang, Da Li, Two novel non-viral gene delivery vectors: low molecular weight polytheylenimine cross-linked by (2-hydroxypropyl)-b-cyclodextrin or (2-hydroxypropyl)-r-cyclodextrin. ChemComm. 2006:2382- 2384 13. GP Tang, HY Guo, F.Alexis, X Wang, S.Zeng, T.M.Lim, J.Ding, Y.Y.Yang, S Wang Low molecular weight polyethylenimine linked by b-cyclodextrin for gene transfer into the nervous system. The Journal of Gene Medicine. 2006;8(6):736-744 14. Da Li, Jingzhong Li, Qingqing Wang, Guping Tang, Hai Yu, Xuetao Cao. Combined targeting of polyethylenimine to FGF receptors and integrins on cells surface improves gene transfer efficiency. J. Biomater. Sci. Polymer Edn. 2007;18:545


Project Title: The role of CCRK as a novel CDK-activating kinase in human glioblastoma
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: General Research Fund (GRF)
Start Date: 07/2009
Abstract:
1) To identify proteins that associate with CCRK-cyclin H complex by co-immunoprecipitation and Tandem Affinity Purification (TAP); 2) To determine whether cyclin H and/or the interacting protein subunits are essentia l for the CAK activity of CCRK; 3) To examine if the CCRK-cyclin H holoenzyme complex is a bona fide cancer target.


List of Research Outputs

An X. , Ng S.M. , Xie D., Zeng Y.X., Sze J. , Wang J. , Chen Y.C., Chow B.K.C. , Lu G., Poon W.S., Kung H.F., Wong B.C.Y. and Lin M.C. , Functional characterisation of cell cycle-related kinase (CCRK) in colorectal cancer carcinogenesis. , European Journal of Cancer . 2010, 46: 1752-1761.


Researcher : Ng SS

List of Research Outputs

Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.


Researcher : Ng WC

List of Research Outputs

Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea : Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Ng W.C. , Leung T.Y. and Williams G.A. , Comparative proteomic responses in two intertidal limpets (Cellana grata and Cellana toreuma) to summer low tides on tropical rocky shores, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology . July 7-10, 2009. Beijing, China . 2009.


Researcher : Ng YLS

List of Research Outputs

Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.


Researcher : Pan Q

List of Research Outputs

Yan A. and Pan Q. , The N- and C- terminal regions of E. coli global transcription factor FNR participate in regulation of FNR protein levels, Molecular Genetics of Bacteria and Phages Meeting 2009, August 4-9, Madison, WI, USA . 2009.


Researcher : Pang CC

List of Research Outputs

Pang C.C. and Saunders R.M.K. , Floral phenology and breeding system of Desmos chinensis (Annonaceae): protogyny and intra-individual floral synchronicity to promote out-crossing, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.


Researcher : Park TJ

List of Research Outputs

Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zool ogy, July 7-10, 2009. Beijing, China . 2009.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothion ein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollut ion and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Park TJ

List of Research Outputs

Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydro gen peroxide, The 3rd International Symposium of Integrative Zoology, July 7-10, 2009. Beijing, China . 2009.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Partanen HA

List of Research Outputs

Partanen H.A. , El-Nezamy H.S. , Leppanen J.M., Woodhouse H.J. and Vahakangas K.H., Aflatoxin B1 Transfer And Metabolism In Human Placenta, Toxicological Sciences . 2010, 113: 216-225.


Researcher : Peng X

List of Research Outputs

Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Peng X

List of Research Outputs

Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Pointing SB

Project Title: Development of an on-line platform for problem-based learning in the interdisciplinary science subject ‘Origins of Life and Astrobiology’
Investigator(s): Pointing SB, Kwok S
Department: Ecology & Biodiversity
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 06/2007
Abstract:
Objectives To develop an on-line platform (also with CD-ROM) for problem-based learning in the interdis ciplinary science subject ‘Origins of Life and Astrobiology’. Key issues and problems to be addressed The course ‘Origins of Life and Astrobiology’ is the most popular electiv e course by enrolment in the Faculty of Science (181 students in the last academic year), and enjoys extremely high SET scores for both teacher effectiveness (77.5%) and course effectiveness (76.2%). The success of this course’s appeal lies in its interdisciplinary nature: The subject matter involves an integrative learning experience incorporating concepts from biology, chemistr y and physics. In this way, by considering problems in understanding the conditions required for life to survive on early Earth and other planets, students develop a more integrative view of the sciences and learn in a ‘fun’ way by addressing problems relevant to a topical and exciting concept. The course is already supported by a website designed by the PI that delivers all lecture material, links to relevant websites and other ‘housekeeping’ functions such as examination and coursework instructions, teacher-student chat forum etc (access via www.hku/ecology/extremophiles). The next step in continued improvement and evolution of this popular course is to develop interactive on-line content and this is the purpose of this application. This is perceived as a need that will directly benefit students on courses with high enrolment. Students currently engage in problem-based project work in groups and this is necessitated by the high enrolment on the course and constraints on the teacher’s time. Providing students with the opportunity for problem-based learning on an individual basis is therefore highly desirable and would further enrich the overall learning experience provided by this course. To this end, funding is sought to produce on-line problem based learning tools relevant to astrobiology that students may work through individually and in their own time, and then obtain feedback from the courseware and teacher. The Faculty has clearly stated a desire to further develop teaching efforts in interdisciplinary areas such as astrobiology, and so this endeavour fits well with this vision. It wi ll benefit the maximum possible number of students and also has value in providing a basis for future development of similar courseware in other courses. The co-investigator at NASA will provide copyright-released imagery and data from current Mars exploration missions for parts of the courseware and this will add authenticity to the overall experience for the student.


Project Title: Microbial composition of urban aerosols in Hong Kong and implications for environmental quality and public health
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2007
Abstract:
Purpose of the project: Determine the prokaryotic microbial composition of urban aerosols in Hong Kong, including identification of potentially harmful taxa, and establish the extent of pollution and climate related temporal variation. Key Issues and problems to be addressed: Why study aerobiology? Microorganisms are responsible for beneficial, benign and harmful effects to man and the environment, and a common featu re of most microorganisms is that they are transported in the air. The study of aerobiology is therefore of key importance in understanding the dispersal, ecology and evolution of microorganisms. With the recent regional emphasis on emergent diseases, public health in relation to air quality, indoor air quality, and dust storms (that transport and protect aerial microorganisms) related to environmental degradation, plus the increasing threat of bio-terrorism worldwide, it is timely that an inventory of Hong Kong’s microbial aerosol is proposed. Remarkably little is actually known about atmospheric microbial composition, and indeed there is no data on the atmospheric aerobiology of Hong Kong or any other regional city or rural area, despite some focus on indoor air quality (e.g. Sci Total Env 273: 27-40 ; and the unpublished work of the Indoor Air Quality Association [IAQA] that mainly focuses on fungal spores and pollen). The increasing awareness of climate change also adds necessity to the need for an understanding of Hong Kong’s aerobiology. Dust storms associated with climate-related environmental degradation are increasingly more common in China, and similar dust storms in Africa have been linked to increased transport of human pathogens such as Neisseria meningitidis (WHO , 2003), those causing environmental damage such as coral reef disease (Geophys Res Lett 27: 3029-3032), and illness from non-specific cause such as pediatric asthma (Int J Biometeorol 49: 371-376). What do we already know? Very little is known about atmospheric aerobiology. Early studies showed that culturable bacteria were concentrated in aerosols created by plant canopy and the sea surface (Appl Environ Microbiol 50: 1229-1232; Science 197: 763-764; J Aerosol Sci 36: 801-812). Viable Fungi and bacteria have also been characterized from high altitudes of up to 20,000m (Aerobiologia 20: 135-140). Recent work has focused upon dust storms in Africa and as these travel in the atmosphere across oceans (Aerobiologia 20: 99-110; Aerobiologia 21: 1-19; Aerobiologia 22: 211-226). These studies have demon strated inter-hemispheric dispersal and viability among a range of cultivable fungi and bacteria, with a clear positive correlation between dust loading in the atmosphere and microbial occurrence. A problem with these approaches is of course it is now widely accepted that cultivable microorganisms represent only a fraction (and also a very skewed fraction!) of total diversity. The relative ease and affordability of metagenomic approaches to community analysis are just starting to be applied to aerobiology. These have the advantage that by removing the need for cultivation a much more representative picture of community structure can be obtained. One study used ARISA to form community genetic fingerprin ts of two air samples from rural France (Atmos Environ 39: 3687-3695). Clone library analysis of 16S rRNA genes from one sample revealed a predominance of proteobacteria, in contradiction to earlier cultivation studies. Earlier this year the first comprehensive metagenomic analys is of aerobiology was published for urban aerosols in two US cities (Proc Natl Acad Sci USA 104: 299-304). This approach used a combination of microarray and clone libraries to establish an extremely biodiverse aerosol with diversity levels approaching those of soil. Importantly they also identified numerous pathogenic taxa including some relatives of bio-terrorism agents. This study proposed that temporal and meteorological factors were more likely to shape aerosol diversity than geographic location between two US cities. What are the research gaps and how can they be addressed? Key questions for further work are: 1. What is the microbial composition of urban aerosols in a tropical seasonal climate such as Hong Kong? 2. What anthropogenic (i.e. respirable suspended particles) and climatic variables are significant over an annual seasonal cycle? 3. Is there a significant risk from pathogens in Hong Kong’s urban aerosol? These questions are proposed to be addressed in the Objectives section of this research proposal. The PI has extensive experience and a proven publication track record in the field of resolving microbial community structure using metagenomic (envir onmental phylogenetic) approaches, including recent papers in the leading journal within the field of environmental microbiology (Environmental Microbiology, impact factor 4.6) plus several others in journals ranked within the top 25% of their field. Objectives: 1. Conduct a regular sampling of urban aerosols in Hong Kong over a 12-month period at several locations and apply metagenomic analysis of microbial community str ucture (in Objective 2). Also concomitantly to collect climatic data including temperature, RH, respirable suspended particles, wind speed and direction data from EPD weather stations. 2. Carry out a culture-independent molecular survey of community structure for all samples, using TRFLP of 16S rRNA genes, and then construct representative clone libraries to establish phylogenetic identity of taxa. To give particular focus to the identification of potentially pathogenic taxa and risk assessment. 3. Establish temporal pollution and climate related patterns in aerosol microbiology by conducting multivariate analysis with regard to abiotic variables.


Project Title: Metagenomic and proteomic analysis of microbial colonization, productivity and adaptation to moisture stress in Chinas deserts'
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2008
Abstract:
(1) Elucidate microbial community composition at the metagenomic level for lithic crusts on quartz from desert locations along a well-defined environmental gradient of moisture stress in China and other reference locations worldwide; (2) Determine the extent of net primary productivity by lithic crusts at different aridity-defined locations and under controlled labor atory conditions simulating various environmental conditions; (3) Examine the response to desiccation stress and re-wetting at the proteomic level for membrane and cytosolic components of selected crust taxa isolated from the most dry-adapted communities.


Project Title: Microbial ecology of lithic communities in Antarctica's Dry Valleys
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
The key objectives of the proposed study are: 1. Establish distribution on a landscape-scale for lithic microbia l colonization in the Antarctic Dry Valleys Special Protected Area. 2. Quantitatively determine overall community diversity and the metabolically active fraction of communities. 3. Elucidate the phylogenetic history of communities in order to understand their origins and dispersal, thus contributing to the broader issue of resolving microbial biogeography. 4. Determine the effect of abiotic variables on diversity using multivariate analyses, in order to understand the abi otic drivers of microbial diversity in cold polar desert ecosystems. Key issues and problems to be addressed: The Antarctic Dry Valleys are a unique and endangered hyper-a rid ecosystem that has been poorly studied - The Antarctic Dry Valleys are unique on Earth, yet threatened by catastrophic ecosystem shift due to climate change. - A pilot survey in January 2008 by the PI identified for the first time lithic microbial communities throughout Dry Valleys locations. - There is no existing information on landscape scale ecology for such communities, thus the actual distribution of the main biotic component of the Dry Valleys is unknown. - Species composition of these communities is not understood, especially which taxa are metabolically active. The Antarctic Dry Valleys provide an ideal natural observatory for testing fundamental ecological hypotheses of broader relevance to microbial ecology - This terrestrial Antarctic ecosystem is ideal for studies of relevance to broader issues in microbial ecology: It is dominat ed by microbial processes and characterized by low-complexity microorganism-driven food-webs, with a relatively limited range of abiotic drivers affecting diversity but high selective pressure due to extreme conditions. - The degree to which microorganisms exhibit phylogeography remains unresolved, and the isolated Antarctic location is ideal for phylogeographic studies. The PI has the only global collection of samples from arid and hyper-arid deserts on every continent on Earth for comparison, thus giving true global significance to the study. - There is currently no consensus on the evolutionary origins of Antarctic microbiota, and the phylogenetic dataset proposed by this study will address this. - Landscape scale studies that allow meaningful statistical inferences of abiotic variables at the community level are lacking, and an Antarctic model would have far-reaching applications in other areas of microbial ecology.


Project Title: Xth SCAR International biology Symposium Dry permafrost polygonal terrain in the Antarctic Dry Valleys supports multiple lithic microbial niches
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Metabolically active microbial community in semi-arid, arid and hyper-arid soils in China's Taklimakan Desert
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 02/2010
Abstract:
The objectives of the proposed study are to: 1. Establish metabolically active fractions of total microbial community (archaea, bacteria, eukarya) in semi-arid, arid and hyper-arid regions of the Taklimakan Desert in western China. 2. Determine the influence of abiotic factors on microbial community development, with particular focus on the role of salinity-related variables. 3. Elucidate the ability of soil communities to fix carbon and nitrog en in situ and under simulated stress in laboratory conditions. Key issues and problems to be addressed 1. Deserts constitute the most abundant biome in China (>30% land mass) and on a global scale are the most prevalent terrestrial ecosystem (>16% global land mass). Desertification (creation of new desert) is an increasing concern in China and worldwide, with serious economic consequences. 2. Desert soils are poorly understood in terms of their microbiota and their ecological role in soil conditioning. The few studies undertaken have focused upon morphology and DNA-based biodiversity and so no indication of which microbes are active is available. This is especially pertinent given the ability of many desert microbes to produce resting structures. 3. Microbial carbon and nitrogen input to desert soils are critical steps in creating conditions suitable for higher plants and the contribution of soil microorganisms requires quantifying. 4. Soil Salinization and catastrophic ecosystem shift resulting from long term water stress is a major environmental concern in China, and evidence is emerging that microbial colonization may mitigate this process. The major studies undertaken on desert microbiology in recent years have been published by the PI and so he is well-placed to move forward this field of research: 1. Pointing SB, Warren-Rhodes K, Lacap DC, Rhodes KL and McKay CP (2007) Hypolithic community shifts occur as a res ult of liquid water availability along environmental gradients in China’s hot and cold hyperarid deserts, Environmental Microbiology 9: 414-424 (impact factor 4.9). 2. Warren-Rhodes KA, Rhodes KL, Boyle LN, Pointing SB, Chen Y, Liu S, Zhou P and McKay CP (2007) Cyanobacterial ecology across environmental gradients and spatial scales in China's hot and cold deserts, FEMS Microbiology Ecology 61: 470-482 (impact factor 3.3). 3. Warren-Rhodes K, Rhodes KL, Pointing SB, Ewing S, Lacap DC, Gómez-Silva B, Amundson R, Friedmann IE and McKay CP (2006) Hypolithic cyanobacteria, dry limit of photosynthesis and microbial ecology in the hyperarid Atacama Desert, Chile, Microbial Ecology 52: 389-398 (impact factor 2.8).


List of Research Outputs

Pointing S.B. , Ecology of terrestrial thermophiles: insights from field sites in Tibet, Thermophiles 2009, Beijing, China . 2009.
Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Pointing S.B. , Service Contribution Award, Faculty of Science, HKU . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.
Wong K.Y. , Lau C.Y. , Bugler-Lacap D.C. , Aitchison J.C. , Cowan D.A. and Pointing S.B. , Endolithic microbial colonization of limestone in a high-altitude arid environment, Microbial Ecology . Springer Science, 2009, 59: 689-699.


Researcher : Sadovy YJ

Project Title: 6th Indo-Pacific Fish Conference The Society for the Conservation of Reef Fish Aggregation (SCFRA) Perplexing Problems of Sexual Patterns in the Genus Paralabrax
Investigator(s): Sadovy YJ
Department: Ecology & Biodiversity
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2001
Abstract:
N/A


Project Title: Molecular population structure of three commercially important groupers in the Indo-Pa cific
Investigator(s): Sadovy YJ
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) Determine whether the populations of the three species are open or closed, And if closed, what the degree of connectivity among regions; (2) As the spawning aggregation dynamics of the two target species differ in spatial scale, our comparative analysis will help to discriminate any relationship between patterns of aggregation behavior and genetic connectivity in aggregating reef fishes of relevance to both management and an understanding of population demography.


Project Title: Population genetic structure of an exploited marine aquarium fish, the mandarinfish, Synchiropus splendidus revealed using microsatellite markers
Investigator(s): Sadovy YJ, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2009
Abstract:
World popularity in the marine aquarium hobby ha s been increased since 1990s (FAO 1995). Although hundreds of different species may be taken for marine aquaria, the most intensely targetted marine fish for the aquarium industry are represented by are relatively few species. Among 4000 coral reef fishes with less than 7.5% speci es collected (FAO 1995). Most of these species are demanded because of their conspicuous colour or special fin morphology, and because of their small size. Until now, 95% of these species are wild-caught from the coral reef environment (Polunin & Roberts 1996; Chan & Sadovy 1998). The mandarinfish or mandarin dragonet (Synchiropus splendidus), is a small and colourful member of the dragonet family (Callionymidae), which is one of the favorite choices in the marine aquarium trade including in Hong Kong (Chan & Sadovy 1998). The mandarinfish is native to the west Pacific region, distributed from the Ryukyu Islands of southern Japan to New Caledonia (Myers 1999). Because of their spectacular fin morphology fishing pressure particularly focused on the males, especially the large ones (Sadovy et al. 2001) and about 70% of caught individuals were recorded to be males. Despite their popularity in the aquarium trade, mandarinfish are considered difficult to maintain in captivity as their feeding habits are very specific (Wilkerson 1996), and their mortality in captivity is typically very high. The Philippines is an important source of the mandarinfish for the aquarium trade (Debelius & Baensch 1994), and exploitation has been particularly high from a circumscribed geographic area located centrally the island of Batasan (Sadovy et al. 2001). The mandarinfish was a major source of income for this Island, and during the peak fishing period (1987-1995), fishers were able to capture at least 1000 fish in 3 hours. Notable reductions in fish size (from average 60 mm TL to 30 mm TL, close to the size of sexual maturation) and abundance was recorded by 1990 (Sadovy et al. 2001). The fishing activity for the mandarinfish is still active although it is not as high as in 1990s, and the fish abundance has not yet recovered back to former levels. In recent years, concerns have been expressed in relation to heavily exploited fish species because of the possibility that exploitation pressures could become a powerful selection pressure if fishing mortality is much more than natural mortality rates or is highly selective (Consuegra et al. 2005). Potential impacts of genetic changes of the exploited populations could be: alteration of population subdivision, loss of genetic variation, and selective genetic changes such as?? (Allendorf et al. 2008). Understanding the genetic changes and evolutionary responses of exploited populations is crucial for management designs aimed at sustainable exploitation of natural populations (Walsh et al. 2006). The mandarinfish is a valued marine aquarium fish subjected to a heavy sex-selective fishery on larger males for their higher attractiveness to aquarists and better value to fishers. Being one of the smallest of all marine pelagic spawners, the mandarinfish has a low fecundity (egg batch size ranges from 12-205), spawns in sheltered inshore waters and has very short larval durations (about 14 days) (Sadovy et al. 2001). In some ways similar to clownfish, this species is likely to show higher population structure than other pelagic spawners (Buston et al. 2007). In addition to its life history, the male-based selective fishery on the mandarinfish could affects mating systems because females prefer to spawn with large males (PI’s unpublished data), and thus potentially affect the recruitment (Vincent & Sadovy 1998; Allendorf and Hard 2009). In this proposed study, we will use a population genetic approach to investigate potential discrepancies between population s subjected to different levels of fishing pressure over a meso-geographical spatial scale across the central Philippines using microsatellite markers. Microsatellites are genetic markers, which have been applied and shown to be very sensitive (Ng et al. 2003) and ideal for population structure analyses in different organisms (Rhodes et al. 2003; Ng et al. 2009). By examining for population genetic sub-structuring in a commerciall y important marine fish, within a relatively circumscribed geographic area and including areas under high and low fishing pressure, the results from the proposed research could have important conservation and management implications (Vincent & Sadovy 1998). Research objectives: (1) To isolate and characterize novel polymorphic microsatellite markers for population analysis of the mandarinfish. (2) To investigate genetic sub-structuring of the mandarinfish across the Philippines using newly developed polymorphic microsatellite marker from objective (1). Allendorf FW, England PR, Luikart G, Ritchie PA, Ryman N (2008) Genetic effects of harvest on wild animal populations. Trends in Ecology & Evolution 23(6):327-337. Allendorf FW, Hard JJ (2009) Human-induced evolution caused by unnatural selection through harvest of wild animals. Proceeding of the National Academy of Sciences of the United States of America 106: 9987-9994 Suppl. 1. Buston PM, Bogdanowicz SM, Wong A, Harrison RG (2007) Are clownfish groups composed of close relatives? An analysis of microsatellite DNA variation in Amphiprion percula. Molecular Ecology 16: 3671–3678. Chan TTC, Sadovy Y (1998) Profile of the marine aquarium fish trade in Hong Kong. Aquarium Sciences and Conservation 2:197-213. Consuegra S, De Leaniz CG, Serdio A, Verspoor E (2005) Selective exploitation of early running fish may induce genetic and phenotypic changes in Atlanti c salmon. Workshop on Genetic Protein Variation in the Atlantic Salmon pp129-145. Debelius H, Baensch HA (1994) Marine Atlas. Mergus, USA. FAO (1995) Review of the State of World Fishery Resources: Aquaculture. FAO Fisheries Circular, Rome. Myers RF (1999) Micronesian Reef Fishes. 3rd edn. Coral Graphics, Guam. Ng WC, Sadovy Y, Leung FCC (2003) Mating system of the rockfish, Sebastiscus marmoratus as revealed by DNA fingerprinting. Ichthyological Research 50(4): 339-348. Ng, W.C., Chan, M.N., Slingsby, G., Williams, G.A. & Leung, F.C.C., 2009. Isolation and characterization of microsatelli te markers from the limpet Cellana grata. Molecular Ecology Resources 9(3): 902-904. Polunin NVC, Robert CM (1996) Reef Fisheries. Chapman and Hall, London. Rhodes KL, Lewis RI, Chapman RW and Sadovy Y (2003) Genetic structure of camouflage grouper, Epinephelus polyphekadion (Pisces: Serranidae), in the western central Pacific. Marine Biology 142: 771-776. Sadovy Y, Mitcheson G, Rasotto MB (2001) Early development of the mandarinfish Synchiropus splendidus (Callionymidae), with notes on its fishery and potential for culture. Aquarium Sciences and Conservation 3: 253-263. Vincent, ACJ, Sadovy Y (1998). Reproductive ecology in the conservation and management of fishes. In Behavioural Ecology and Conservation Biology (T Caro ed.). Oxford University Press, New York, pp. 209-245. Walsh MR, Munch SB, Chiba S, Conover DO (2006) Maladaptive changes in multiple traits caused by fishing: impediments to population recovery. Ecology Letters 9: 142–148. Wilkerson J (1996) C-Quest Hatchery-Innovations in captive ornamental marine fish culturing. Freshwater and Marine Aquarium 19(4): 123ff.


List of Research Outputs

Albins M. .A., Hixon M. .A. and Sadovy Y.J. , Threatened fishes of the world: Epinephelus striatus (Bloch, 1792) (Serranidae), Environmental Biology of Fishes . 2009, 86: 309-310.
Rasotto M. .B., Sadovy Y.J. and Mitcheson G.R. , Male body size predicts sperm number in the mandarinfish, Journal of Zoology . 2010, 281: 161-167.
Sadovy Y.J. , Liu M. and Suharti S., Gonadal development in a giant threatened reef fish, the humphead wrasse Cheilinus undulatus, and its relation ship to international trade, Journal of Fish Biology . 2010, 77: 706-718.


Researcher : Saunders RMK

Project Title: Systematics and phylogenetics of Uvaria (Annonaceae) and related genera: an integrated morphological, molecular and ecological approach
Investigator(s): Saunders RMK, Su YCF
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2006
Abstract:
(1) analysis of morphology, ultrastructure and anatomy: delimitation of taxonomic characters and preliminary assessment of character homology (based on Uvaria species from western Malesia); (2) Development of a species-level classification of Uvaria species in western Malesia; (3) Gene sequencing and phylogenetic analysis (selected Uvaria species); (4) analysis of phenology and reproductive biology (selected Uvaria species); (5) analysis of species conservation status (for Uvaria species from western Malesia)


Project Title: Molecular phylogenetics of Cananga, Cyathocalyx and Drepananthus (Annonaceae): implications for generic delimitation, morphological evolution, and historical biogeography
Investigator(s): Saunders RMK, Su YCF
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2007
Abstract:
(1) To reconstruct the phylogeny of the Cyathocalyx group using a ‘multigene’ approach in order to assess generic monophyly and delimitation, and recognise supraspec ific taxa within genera. (2) On the basis of the generic delimitation achieved, to prepare the unpublished species-level classification of Cyathocalyx sensu lato for publication as a monograph (or as separate monographs of Cyathocalyx sensu stricto and Drepananthus, as appropriate) in the Systematic Botany Monographs series. (3) Using the phylogeny developed, to assess morphological homologies and examine the evolution of morphological characters and selected ecological processes. (4) To interpret the historical biogeography of the group using cladistic methods, parsimony analysis of endemism (PAE), and event-based methods.


Project Title: Homeotic mutation and floral evolution in the Dasymaschalon-Desmos-Friesodielsia clade (Annonaceae) of basal angiosperms
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
The Annonaceae is a species-rich pantropical family of trees and woody climbers. The family is of phylogenetic significance as they possess many apomorphic characteri stics despite being ‘basal angiosperms’, derived from lineages that appeared before the evolution of the eudicots. Recent phylogenetic research by the PI’s research group has highlighted confusion in the existing delimitation of three closely related genera, Dasymaschalon (27 species), Desmos (25–30 species) and Friesodielsia (40–60 species). Phylogenetic relationships between Dasymaschalon and Desmos remain unresolved, with Dasym aschalon species represented by two clades that form a polytomy with a clade composed of Desmos species. In addition, Friesodielsia is shown to be polyphyletic, with a clade of Asian representatives (consisting of F. desmoides and F. kingii) sister to one of the Dasymaschalon clad es; the other Friesodielsia species sampled are not closely related. This research proposal focuses on this Dasymaschalon-Desmos -Friesodielsia clade, with the objective of increasing resolution and investigating morphological character evolution, with particular reference to floral structures. Preliminary data generated by members of the PI’s research group (J. Wang, Y.C.F. Su & R.M.K. Saunders, unpubl. data) consists of sequences of two coding and two non-coding chloroplast DNA regions: matK, psbA-trnH spacer, rbcL and trnL-F spacer. Although Dasymaschalon has been extensively sampled, with 22 of the total 27 species (c. 80%), the other genera have been comparatively poorly sampled, with only eight species of Desmos and four species of Friesodielsia. Further sampling of the latter genera is clearly essential, although for the purposes of this study only representatives of the Friesodielsia clade associated with Dasymaschalon will need to be sampled. The close phylogenetic relationship between Dasymaschalon, Desmos and Fries odielsia (pro parte) is superficially surprising, since they possess markedly divergent floral forms. The flowers of all three genera have a partially enclosed ‘pollination chamber’ associated with pollination by small beetles, although the anatomical structure of this chamber var ies. Desmos flowers have six subequal petals in two whorls of three; the inner petals are basally constricted around the androecium and gynoecium, with small apertures (enabling access by pollinators) at the base of the inner petals partly obstructed by the base of the outer petals. Friesodielsia flowers also have six petals in two whorls of three, but the pollination chamber is formed by apically connivent inner petals; the apert ures between the base of the inner petals are again partly obstructed by the base of the outer petals. Dasymaschalon shows a very different floral structure, however, with only three petals in a single whorl; the position of these petals indicate that they are unequivocally homolo gous with the outer petals of Desmos and Friesodielsia. Despite the different developmental origin of these petals, they are structurally identical to the inner petals of Friesodielsia. This suggests that floral evolution in the Dasymaschalon-Desmos-Friesodielsia clade may have involved a disruption to the genetic control of floral organ development. Early studies of the genetics of floral development were focused on the model flowering plants Arabidopsis (Brassicaceae) and Antirrhinum (Plantaginaceae). These studies enabled clarification of the ‘ABC model’, which suggests tha t the identity of floral organs is specified by at least three classes of homeotic genes, A, B and C; expression of the B-function genes provides the critical difference between sepals (A) and petals (AB), and between stamens (BC) and carpels (C) (e.g., V.A. Albert et al. in D.E. Soltis et al., eds., Molecular Systematics of Plants, vol. 2: 349–374; 1998). Alternative hypotheses have been derived to explain the control of floral development in basal angiosperms, which generally show poor differentiation between sepaloid outer tepals and petaloid inner tepa ls (e.g., D.E. Soltis et al., Ann. Bot. 100: 155–163; 2007). Unlike most basal angiosperms, however, the Annonaceae have flowers that show clear differentiation between sepals and petals. Despite the lack of homology between the sepal-petal distinction in eudicots and the Annonaceae, floral development in Asimina (Annonaceae) appears to be controlled by an ABC model paralleling that described for eudicots (S. Kim et al., Pl. J. 43: 724–744; 2005). An elaboration of this ABC model presumably operates in most Annonaceae genera, including Desmos and Friesodielsia, which show a morphological distinction between the inner and outer whorls of petals. Recognition of the extensive morphological differences between the perianths of Dasymaschalon, Desmos and Friesodielsia flowers as a series of distinct characte rs and character states does not enable identification of a parsimonious explanation of evolutionary change. It can be hypothesised, however, that the extensive changes in perianth structure are the product of homeotic mutations, in which inner petal development in Dasymaschalon is suppressed, with outer petal development controll ed by the genes previously responsible for inner petal development. Circumstantial support for this hypothesis is found in two Dasymaschalon species, D. macrocalyx and D. trichophorum, which form a well-supported clade (1.00 posterior probability) in preliminary Bayesian phylogenetic analyses (J. Wang, Y.C.F. Su & R.M.K. Saunders, unpubl. data). These species both have sepals that are large and resemble the outer petals of Friesod ielsia, in contrast with all other Dasymaschalon species which have very small sepals. As with most Annonaceae, the sepals only enclose the flower buds in the very earliest developmental stages and hence do not protect the develop ing floral organs. Given the apparent absence of any functional explanation for the enlarged sepals of D. macrocalyx and D. trichophorum, it is possible that their evolution is also the result of a homeotic mutation, with developm ent controlled by genes previously responsible for outer petal development. The proposed research aims to clarify problems of generic delimitation in the Dasymaschalon-Desmos-F riesodielsia clade by generating phylogenetic hypotheses with improved resolution and statistical support, based on a more comprehensive level of taxon sampling. The reconstructed phylogeny will enable interpretation of morphological character evolution, with emphasis on floral evolution. In particular, the phylogeny will be used to interpret the possibility of homeotic mutations as an explanation for changes in perianth structure.


Project Title: Molecular phylogenetics of Polyathia (Annonaceae): identifying clades and morphological synapomorphies in a large polyphyletic genus
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2009
Abstract:
1) To increase the taxonomic breadth of the phylogenetic analyses by incorporating more species than sampled previously, including species of Polyalthia and relat ed genera; 2) To increase the resolution and support of the phylogenetic reconstructions of Polyalthia sensu lato by assessing the utility of other gene regions for multiple-gene analyses; 3) To identify morphological synapomorphies for each of the constituent clades in order to enable taxonomic recognition as distinct genera; 4) To resolve outstanding nomenclatural problems and validate new generic names and species combinations as required; 5) To estimate divergence times for individual clades and elucidate patterns of historical biogeography.


Project Title: Molecular phylogenetics of the Fitzalania-Meiogyne clade (Annonaceae): taxonomic and biogeographical implications
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
The Annonaceae is a species-rich pantropical family of flowering trees and woody lianas. The family is of phylogenetic significance as they possess many apomorphic characteristics despite being ‘basal angiosperms’, derived from lineages that appeared before the evolution of the eudicots. The PI’s research group is now one of the leading international teams studying the phylogeny of the family, and using the results to address ques tions in higher-level systematics, evolutionary diversification and historical biogeography. The genus Fitzalania consists of only two species from Queensland, Australia (Jessup, Fl. Australia 2: 18-57; 2007), whereas Meiogyne consists of 15 described species, ranging from southern India to New Caledonia (van Heusden, Blumea 38: 487-511; 1994; van Heusden, Bull. Mus. Natl. Hist. Nat., B, Adansonia 18: 75-83; 1996; Jessup, l.c.). The PI is currently preparing descriptions of two previously unknown species for publication. Mols et al. (Amer. J. Bot. 91: 590-600; 2004) included four Meiogyne species and one Fitzalania species in a broad-ranging molecular phylogenetic analysis (based on rbcL and trnL-F regi ons), and showed that the Fitzalania species was nested within a clade composed of the Meiogyne species. Additional sequences for the second Fitzalania species and another Meiogyne species have since been generated in the PI’s lab, and a similar topology retrieved following phylog enetic analysis. Although the levels of taxon sampling are inadequate, the topology indicates that Fitzalania and Meiogyne are likely to be congeneric. One of the initial aims of this project will therefore be to increase the number of species sampled and the range of gene regions sequenced to ensure a well-resolved and well-suppo rted phylogeny. It will then be possible to validate the new nomenclatural combinations arising from the transfer of the Meiogyne species names to the older generic name, Fitzalania, as necessary. Most of the species in the Fitzalania-Meiogyne clade occur east of Wallace’s line, with one species in New Britain (off the east coast of New Guinea), five species in Queensland, Aust ralia, and five species in New Caledonia. This centre of diversity in Australasia is unusual within the Annonaceae, although similar distribution patterns have been observed in a few other genera, such as Pseuduvaria (Su & Saunder s, Syst. Bot. Monogr. 79: 1-204; 2006; Su & Saunders, BMC Evol. Biol. 9: article 153; 2009). Several large-scale biogeographical studies of the Annonaceae have indicated a probable origin in South America and/or Africa, with subsequent dispersal into Asia, either via India and/or southern Europe and central Asia (e.g., Doyle et al., Int. J. Pl. Sci., 165, suppl. 4: S55-S67; 2004; Richardson et al., Philos. Trans. Roy. Soc. Lond., B 359: 1495-1508; 2004). This is consistent with the observation that most Asian Annonaceae genera have a centre of diversity in western Malesia. The unusual geographical distribution of the Fitzalania-Meiogyne clade raises several interesting questions relating to the timing of the presumed dispersal events. Preliminary biogeographical optimizations suggest that early representatives of the Fitzalania-Meiogyne clade are likely to have dispersed eastwards across Malesia, towards Australia and New Caledonia. The best opportunity for biota to “island hop” across Wallacea appears to have been during the last 5 million years, due to: (1) the formation of a substantial landmass in Sulawesi from ca. 5 Mya (Hall, in Metcalfe et al., eds., Faunal and Floral Migrations and Evolution in SE Asia-Australasia, 35-56; 2001); (2) the connection between New Guinea and Sundaland via the Banda and Sunda arcs (Hall, in Hall et al., Biogeography and Geological Evolution of SE Asia, 99-131; 1998); (3) the increasing number of volcanic islands in East Indonesia (Barby & Pierce, Syst. Entomol. 32: 2-25; 2007); (4) the exposure of the Sunda and Sahul Shelves caused by falling sea levels (up to 120 m lower than present levels) during the Pleistocene glaciations (Inger & Voris, J. Biogeogr. 28: 863-891; 2001); and (5) the accretion of microcontinental island arc fragments at the northern edge of the Australian craton portion of New Guinea (Hall in Metcalfe et al., l.c.). We will use uncorrelated lognormal (UCLD) relaxed molecular clock methods to estimate diversification times of the relevant nodes within the phylogeny, with the objective of ascertaining whether the estimated ages are consistent with the geological and palaeoclimatic data available. The taxonomic diversity in New Caledonia is also of considerable biogeographical interest. Analysis of the phytogeographical relationships of the rainforests of New Caledonia (Mora t et al. in Radovsky et al., eds., Biogeography of the Tropical Pacific, 71-128; 1984) suggests that there are two main floristic elements, reflecting associations with Australia and Malesia. The Australian floristic component was previously hypothesized to have resulted from ancient Gondwanan lineages that existed prior to the tectonic separation of New Caledonia from Australia (which occurred approximately 75 Mya according to Ha ll, J. Asian Earth Sci. 20: 353-431; 2002), whereas the Malesian floristic component was regarded as the result of later long-distance dispersal events (Morat et al., l.c.). The New Caledonian representatives of the Annonaceae have been cited as an example of a lineage derived from the break-up of Gondwana (Lowry in Peng & Lowry, eds., Rare, Threatened, and Endangered Floras of Asia and the Pacific Rim, 181-206; 1998; Jaffré et al., Composition et Caractéristiques de la Flore Indigène de la Nouvelle-Calédonie; 2001). Recent geological research, however, has indicated that New Caledonia was completely submerged during the Palaeocene (Aitchison et al., Geology 23: 161-164; 1995), suggesting that all existing lineages in the island’s flora are likely to have been derived by long-distance dispersal with subsequent diversification. Estimates of the ages of the nodes in the phylogeny will again be compared with the available geological and palaeoclimatic data, and will clarify when representatives of the Fitzalania-Meiogyne clade first migrated to New Caledonia.


List of Research Outputs

Attanayake M.A.S...A... , Ratnayake R.M.C. and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Attanayake M.A.S...A... and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.
Chatrou L.W., Richardson J.E., Erkens R.H.J. and Saunders R.M.K. , Natural History of the Annonaceae . 2009.
Ho G.W.C., Mar S.S. and Saunders R.M.K. , Thismia tentaculata (Burmanniaceae tribe Thismieae) from Hong Kong: first record of the genus and tribe from continental China, Journal of Systematics and Evolution . 2009, 47: 605-607.
Pang C.C. and Saunders R.M.K. , Floral phenology and breeding system of Desmos chinensis (Annonaceae): protogyny and intra-individual floral synchronicity to promote out-crossing, 1st Meeting of Biosyst EU 2009 & 7th Biennial Confe rence of the Systematics Association, Leiden, 10-14 August . 2009.
Ratnayake R.M.C.S., Gunatilleke I.A.U.N. and Saunders R.M.K. , Phenology of Xylopia championii in an aseasonal rainforest of Sri Lanka and its correlation with climate, 5th International Canopy Conference, Bangalore, 25-31 October . 2009.
Ratnayake R.M.C.S. and Saunders R.M.K. , Vegetative and reproductive phenology of Polyalthia coffeoides in Sri Lanka, 29th Annual Session of the Institute of Biology, Sri Lanka . 2009.
Ratnayake R.M.C.S., Gunatilleke I.A.U.N. and Saunders R.M.K. , Vegetative and reproductive phenology of Polyalthia korinti and correlation with weather pattern in Sri Lanka, 5th International Canopy Conference, Bangalore, 25-31 October . 2009.
Saunders R.M.K. and Su Y.C.F. , A Late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent diversification in New Guinea, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Saunders R.M.K. , Associate Editor, , Botanical Journal of the Linnean Society . 2010.
Saunders R.M.K. , Homeotic mutations and floral evolution in the Annonaceae, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Saunders R.M.K. , Journal of Systematics and Evolution . 2010.
Saunders R.M.K. , Member of editorial board, Thai Forest Bulletin . 2009.
Saunders R.M.K. , Specialist Adviser, Registrar of Plant Variety Rights, Intellectual Property Department, Hong Kong Government . 2010.
Su Y.C.F. and Saunders R.M.K. , A late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent dispersal in New Guinea, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Su Y.C.F. , Chaowasku T. and Saunders R.M.K. , An extended phylogeny of Pseuduvaria (Annonaceae), with descriptions of three new species and a reassessment of the generic status of Oreomitra, Systematic Botany . 2010, 35: 30-39.
Su Y.C.F. and Saunders R.M.K. , Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea, BMC Evolutionary Biology . 2009, 9: art. 153 (19 pp).
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annon aceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.
Wang J. , Chalermglin P. and Saunders R.M.K. , The genus Dasymaschalon (Annonaceae) in Thailand, Systematic Botany . 2009, 34: 252-265.
Weerasooriya A.D. and Saunders R.M.K. , Monograph of Mitrephora (Annonaceae), Systematic Botany Monographs . Ann Arbor, Michigan, American Society of Plant Taxonomists, 2010, 90: 1-167 + 4 colour plates.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cyathostemma, Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodor um, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Shan B

List of Research Outputs

Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw po rk, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.


Researcher : Shi M

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Shih CH

List of Research Outputs

Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyantho cyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Shih CH

List of Research Outputs

Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocya nidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Sin YT

List of Research Outputs

Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscylliu m plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Sit WH

List of Research Outputs

Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wan J.M.F. , Sit W.H. and Yang X., Polysaccharopeptide of Coriolus versicolor enhances the Anticancer Activity of Camptothecin (CPT) on Human Leukemic HL-60 Cells, The 5th International medicinal Mushroom Conference . 2009, 691-702.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.
Zhong W. , Sit W.H. , Wan J.M.F. and Yu A.C.H. , Sonoporation-induced apoptosis and cell-cycle arrest: initial findings, International Symposium on Therapeutic Ultrasound . 2010, D3-1.


Researcher : Su X

List of Research Outputs

Su X. and Tsang J.S.H. , Identification of a second haloacetic acid transporter in a haloacetate degrading bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . 2010.


Researcher : Su YCF

List of Research Outputs

Saunders R.M.K. and Su Y.C.F. , A Late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent diversification in New Guinea, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Su Y.C.F. and Saunders R.M.K. , A late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent dispersal in New Guinea, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Su Y.C.F. , Chaowasku T. and Saunders R.M.K. , An extended phylogeny of Pseuduvaria (Annonaceae), with descriptions of three new species and a reassessme nt of the generic status of Oreomitra, Systematic Botany . 2010, 35: 30-39.
Su Y.C.F. and Saunders R.M.K. , Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea, BMC Evolutionary Biology . 2009, 9: art. 153 (19 pp).
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cy athostemma, Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodorum, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Sun M

Project Title: Molecular evolution of SSIIa gene during domestication and SNP markers for rice breeding
Investigator(s): Sun M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
Oryza sativa is one of the oldest domesticated crop species in the world, and O. rufipogon, found widely in Asia, is believed to be the wild progenitor of domesticated rice (Khush 1997). The two species differ in a variety of quantitative traits, including panicle and spikelet structure, seed weight, and seed dormancy. Two major subspecies, O. sativa ssp. indica and O. sativa ssp. japonica, together account for most of the rice cultivars and landraces currently grown. Domestication of wild rice probably started about 11,000 years ago. Domestication in Asia could have occurred independently and concurrently at several sites (Khush 1997). A recent phylogeographic study has shown that cultivated rice was independently domesticated at least twice from different O. rufipogon populations, which resulted in the two subspecies, indica and japonica (Londo et al 2006). The subspecies indica was domesticated within a region south of the Himalaya mountain range, likely eastern India, Myanmar, and Thailand, whereas japonica was domesticated from wild rice in southern China (Londo et al 2006). During the long history of rice domestication and cultivation, divergent starch qualities of the grain may be selected and selection could have acted on the starch biosynthesis genes. For example, the splice-site mutation of Wx gene has been under selection in most low-amylose rice landraces cultivated widely in Northeast Asia. And sequence analysis has suggested that selection pressures associated with crop domestication can even exceed those observed for genes under strong natural selection. Our previous work has shown that two continuous single-nucleotide polymorphisms (SNPs), GC/TT of starch synthase IIa (SSIIa) in cultivated rice, have a very strong associ ation with gelatinization temperature (GT) of starch, and can be used to differentiate high or intermediate GT rice from low-GT rice. Other cereal crops, such as wheat, barley and maize, all captured the same amino acid associated with high-GT as rice, suggesting that the related SNP allele GC is most likely the ancestral or wild type in rice. However, polymorphisms at the SNP sites could also exist in wild rice O. rufipogon. Similarly, another important SNP (A/G, 31 bp upstream of the GC/TT SNPs) was found to be crucial for SSIIa activity in cultivated rice. In this project, we will investigate the molecular evolution of SSIIa in relation to GT during rice domestication and breeding. The eating, cooking and processing qualities of rice and rice products are mainly influenced by physicochemical properties of its starch, which accounts for about 90% of milled rice. Starch is composed of amylose and amylopectin, and apparent amylose content has been well recognized as one of the most important determinan ts of rice quality. In addition, differences in amylopectin structure affect rice eating and textural qualities. Gelatinization temperature, one of the most important indicators of cooking quality and processing characteristics of rice starch, is controlled by the fine structure of amylopectin. The project objectives are: 1. To study GC/TT, A/G, and other related polymorphic SNPs in different wild rice populations and their relationship with gelatinization temperature. Wild populations of O. rufipogon from Yunnan, Guangxi and Jiangxi provinces of mainland China will be genotyped and used for measur ement of gelatinization temperature following the methods already developed in our laboratories. 2. To compare SSIIa gene sequence diversity among wild rice, landraces, and cultivars to investigate genetic consequences of domestication. Comparative analysis of gelatinization temperature and other physicochemical properties will also be conducted for these rice samples. 3. To determine the effect of domestication on the other genes up- and down-stream of SSIIa. Domestication and artificial selection on the target genes may have a strong hitchhiking effect on the genes nearby, which can be detected by the sequence diversity analysis. 4. To determine association of SNPs with gelatinizati on temperature in wild rice and compare with the findings in cultivated rice, and to develop PCR-based molecular markers for rice breeding.


Project Title: Botany & Mycology 2009 Molecular identification of hybridization and introgression in Bruguiera (Rhizophoraceae)
Investigator(s): Sun M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Sun M. , Molecular identification of hybridization and introgressi on in Bruguiera (Rhizophoraceae). , Botany & Mycology 2009, Snowbird, Utah, USA . 2009.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemica ls of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.


Researcher : Sun Z

List of Research Outputs

Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Sun Z

List of Research Outputs

Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproduc ts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Surveswaran S

Project Title: 7th Biennial Conference of the Systematics Association Phylogeny of the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group
Investigator(s): Surveswaran S
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Abstract:
N/A


List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Surveswaran S

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Tam CY

List of Research Outputs

Lui W.Y. and Tam C.Y. , Itch interacts with the pre-initiation complex for gene transcription, The 34th Federation of European Biochemical Socie ties (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.


Researcher : Tam KV

List of Research Outputs

Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.


Researcher : Tan-Un KC

Project Title: Molecular and functional character isation of Cytoglobin (CYGB), a hypoxia inducible gene
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2008
Abstract:
(1) To investigate the roles of Sp1 and Sp3 proteins in the regulation of CYGB gene; (2) To characterise the potential regulatory regions that are located distal and proximal to the CYGB gene; (3) To perform a detailed study on the methylation and histone modification stautus of the corresponding CpG islands in order to better understand the underlying molecular mechanism of CYGB gene regulation (4) To analyse the activation of CYGB gene by HIF(hypoxia-inducible factors) through siRNA mediated knockdown of HIF genes; (5) To delineate the biological role of CYGB in the context of oxidative stress; (6) To investigate the association of CYGB expression and its implication in the pathogenesis of chronic obstructive pulmonary disease (COPD).


Project Title: The study of the regulatory regi ons of the human neuroglobin gene
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Completion Date: 08/2010
Abstract:
Globins are oxygen-binding heme proteins found in bacteria, fungi, protists, plants and animals. In vertebrates, two well-known globins, hemoglobin(Hb) and myoglobin(Mb) have been studied for over than a century and are the representatives of the globin family. So far, the vertebrate globin family consists of Hb, Mb, neuroglobin (Ngb), cytoglobin (Cygb), globin E (eye-specific in chicken) and globin X (found in amphibians and fish). Ngb was first discovered in the brains of vertebrates [1]. It is expressed predominantly in the central and peripheral nervous systems, in the retina and in some endocrine tissues [1, 2]. In the brain, Ngb is present in neurons but absent in glia cells [3]. Ngb is hexa-coordinated whilst Hb and Mb are penta-coordinated. Small ligands such as O2, CO and NO can reversibly bind with the heme of Ngb. Phylogenetics analysis indicates that Ngb belongs to a branch of globin family which diverged early in evolution [5]. Current studies imply that Ngb may be a scavenger of NO and reactive oxygen species (ROS) and protect cells from oxidative stress [7]. It has been proposed that Ngb may have a sensoring role for O2/NO in the signal transduction pathway thus acting as a guanine-n ucleotide dissociation inhibitor (GDI) or suppressing apoptosis by reducing ferric cytochrome c [8,9]. To date, the precise function and regulation of Ngb are still unclear. In this study we propose to characterise the analyze a 2kb 5’promoter region of the human Ngb gene. We will search for potential transcription factor binding sites that mediate the regulation of Ngb gene expression.


Project Title: King's/HKU Fellowship Awards 2010-11
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: King's/HKU Fellowship Awards
Start Date: 06/2010
Abstract:
To visit the Division of Genetics and Molecular Medicine of the School of Medicine at King's College London to conduct research and to learn techniques that will assist in the investigation of mapping of regulatory regions and DNA methylation and histone modification in the cytoglobin gene locus, and to develop a new research project in Nutrigenomics.


Project Title: A conditional knockout mouse for cytoglobin
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
OBJECTIVES Cytoglobin (Cygb) is a recently discovered member of the vertebrate globin superfamily. It is found in all tissues, albeit at varying levels, implicating a general function of this ubiquitously expressed protein. Key issues: Liver fibrosis is a common complication of chronic liver disease and end-stage fibrosis (cirrhosis) is a health problem in Hong Kong and world wide. It has been shown that over-expression of Cygb reduces oxidative stress, suppresses extracellular matrix de position in liver fibrosis and promotes the recovery from damage induced fibrogenesis. As a new member of the globin superfamily, cytoglobin(Cygb) was first discovered in hepatic stellate cells(HSCs) of the fibrotic liver and duly named “stellate cell activated protein” (Kawada et al.,2001 J. Biol. Chem. 276 (2001) 25318–25323.). Cygb has been characterized as a respiratory protein in connective tissues and we and others have found it to be up-regulated during hypoxia(low oxyg en) (Fordel et al., Biochem. Biophys. Res. Commun. 319 (2004) 342–348). This suggests that Cygb may play a role in the protection of the cells against oxidative stress by acting as a scavenger for ROS.. Findings from our group (Guo et al.,2007 Biochem Biophys Res Commun. 2007 Dec 7;364(1):145-50) showed that the up-regulation of Cygb was an acute response to hypoxia and was mediated by Hypoxia-inducible factor-1(HIF-1) transcription factor. Our group (Man et al.,2008 Toxicol Lett. 2008 Dec 15;183(1-3):36-44) also showed that Cygb was expressed in hepatic stellate cells(HSC) and found an increase accumulation of Cygb-positive cells during the development of CCl4-induced liver fibrosis. In fibrogenesis, stellate cells proliferate and undergo transition into myofibroblast-like cells.. As CCl4 is known to generate reactive oxygen species (ROS) we suggest that Cygb may play a crucial role in the detoxification of ROS in the pathogenesis of liver fibrosis. Noteworthy, cytoglobin has been identified to be a candidate tumor suppressor gene, as down-regulation of cytoglobin expression is observed in lung tumors. (Xinarianos et al., Hum Mol Genet. 2006 Jul 1;15(13):2038-44.) . Interestingly, we have shown that reduced expression of cytoglobin is correlated with the severity of chronic pulmonary diseases(COPD ) (unpublished data). To date, the physiological function of Cygb is still controversial. Objectives: The primary goal of this project is to understand the functional role of cytoglobin in vivo, and secondarily to address the role of Cygb in the pathogenesis of liver fibrosis. This project will generate a unique and proprietary knockout mouse for the Cygb gene which will provide a useful genetic resource for future tissu e specific KO mice and for the cytoglobin research community. Strategy: As Cygb is expressed ubiquitously in all tissues, a germ line knock out may have defects in numerous tissues or is embryonic lethal. To circumvent this problem, we propose to employ an in vivo conditional knockout Cygb mouse model to investigate the functional role of Cygb. A conditional null allele for Cygb will be generated by homologous recombination in ES cells using the the Cre-loxP and Flp-Frt systems. These conditional knockout mice should facilitate the study of the indivi dual consequences of Cygb deficiency in various tissues. Potential outcomes The expected outcomes of this study will be (figure 1): (a) the generation of Cygb fn/+ (fn denotes floxP-neo) mice carrying the targeted allele with the β-galactosidase-neomycin(β-geo) cassette as a marker. Studies from these mice will give us a global expression profile of cytoglobin during develo pment and in tissues. (b) the generation of a conditional KO heterozygous Cygb fx/+(fx denotes floxP) mice which will serve as an excellent candidate for studies on the role of Cygb in various tissues (c) the generation of GFAP(Glial fibrilliary acidic protein) conditional Cygb△/△ mice where ablation of Cygb expression is restri cted in hepatic stellate cells. It will be a model to study the relevance of Cygb in liver fibrosis. (d) the avail of generating a Cygb fn/fn homozygous KO mice as a knock-out mouse model for further investigation of the function of Cygb. The generation of a knock-out Cygb mouse will allow us to directly examine the function of this protein in vivo in the context of cellular homeostasis. Future work: The conditional knock-out mouse model will be challenged with CCl4 to induce liver fibrogenesis. This latter part of the study will be according to the method that we have previously performed (Man et al., 2009). Results from this experiment will shed light as to whether the absence of Cygb may lead to the accelerated progression to liver fibrosis.


List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.


Researcher : Tang KS

List of Research Outputs

Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptosi s resistance of non-adherent ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 1722) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptotic resistance of ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular- signal regulated kinase 1/2, Neoplasia . 2010, 12: 128-138.


Researcher : Tang WK

List of Research Outputs

Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.


Researcher : Thomson DL

List of Research Outputs

Bonner S.J., Thomson D.L. and Schwarz C.J., Time-Varying Covariates and Semi-Parametric Regression in Capture-Recapture: an Adaptive Spline Approach, Monograph, Environmental and Ecological Statistic s . 2009, 3: 657-675.
Thomson D.L. , Bird-watching and the study of environmental change, Hong Kong Bird Watching Society . 2009.
Thomson D.L. and Lebreton J.D., Conference session organiser/chair, EURING 2009 Analytic al meeting and workshop, Pescara, Italy. http://www.phidot.org/euring2009/, 2009.
Thomson D.L. , Cooch E.G. and Conroy M.J., Modeling Demographic Processes in Marked Populations, New York, Springer, 2009.
Thomson D.L. , Stability and the Habitable Planet - What does it mean for wildlife populations?, Emerging SRT Workshop - Earth as a Habitable Planet, Swire Institute of Marine Science . 2010.
Thomson D.L. , Conroy M.J., Anderson D.R., Burnham K.P., Cooch E.G., Francis C.M., Lebreton J.D., Lindberg M.S., Morgan B.J.T., Otis D.L. and White G.C., Standardising terminology and notation for the analysis of demographic processes in marked populations, Monograph, Environmental and Ecological Statistics . 2009, 3: 1099-1106.


Researcher : Tian R

List of Research Outputs

Tian R. and Tsang J.S.H. , Mutagenic analysis of the upstream regulatory region of a dehalogenase gene in Burkholderia sp. MBA4, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 76.


Researcher : To TKJ

List of Research Outputs

Wang M. , Chu I.K. and To T.K.J. , Application of epigallocatechin gallate to prevent DNA interstrand cross-links caused by reactive carbony l species, 239th ACS national Meeting, San Francisco, CA, USA, March 21-25, AGFD-84 . 2010.


Researcher : Tsang JSH

Project Title: Molecular characterization of a novel bacterial permease that transport haloacid
Investigator(s): Tsang JSH
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2006
Completion Date: 03/2010
Abstract:
(1) Confirmation of the expression of the putative permease gene; (2) confirmation of the putative gene as a second member of a haloacid operon; (3) functional analysis of the putative permease; (4) structural ana lysis of the putative permease protein.


Project Title: Utilization of a microfluidic system for teaching of biotechnology, microbiology and mole cular biology
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 08/2008
Abstract:
The beginning of the twenty-first century can be described as the decade for biological sciences. Since the year 2000 The Nobel Prizes in Medicine have been award to researchers working on many disciplines of biological systems. These include genetic regulations of programmed cell death and cell cycle control, signal transduction in the nervous system, gene silencing by means of double-stranded RNA, discovery of the bacterium Helicobacter pylori and most recently on the use of embryonic stem cells. Moreover, four of the seven Nobel Prizes in Chemistry since the beginning of the decade were also given to researchers in the biological fields. These include methods used for structural analysis of biological macromolecules, channels in cell membranes, ubiquitin-mediated protein degradation and the molecular basis of eukaryotic transcription. In order to teach students enrolled in the biologica l sciences programmes it is necessary to ensure that the most updated information will be delivered to these students. Today the major techniques used for analysis of biological systems involve the studies of DNA, RNA and protein. Preparative and analytical electrophoresis systems were normally used for these investigations. Traditionally, agarose and polyacrylamide gel electrophoresis systems were used for separation of these biomolecules. Since these biomolecules have different abundance and properties in the cell it is naturally necessary to enhance the detection of these substances with the addition of specific reagents. Ethidium bromide is usually used to bind to nucleic acids and help visualize the presence of DNA and RNA. In this detection method the samples in the gel were identified with the illumination of ultraviolet light. Since the visualization processes depended on the binding of the chemical to the biomolecules this reagent is unavoidably hazardous. Ethidium bromide is a chemical carcinogen and has been one of the chemical pollutants being transmitted easily without any notice. Ultraviolet light has also been used as a physical mutagen. It can also causes sever damage to the eyes when no protection was provided. The skins can also get burnt without any tanning effect when exposed to ultraviolet light. This obviously posed certain level of danger to the user and to the workers in the surrounding environment. Polyacrylamide has been used for the separation of proteins and for small sized DNA and/or RNA. In the old times people used to use their finger to check whether the acrylamide gel has been set or not. It has later been found that acrylamide is a neurotoxin. The use of these chemicals in teaching biological sciences subjects has to be exceptionally careful in order not to radiate their harmful effect. The use of a microfluidic automated electrophoresis system has the advantage of maintaining the separation functions while removing the hazardous aspect. No harmful che mical is used in the automated system and students will be able to appreciate the safety and usefulness of this kind of technology. When the traditional electrophoresis systems were used for analysis of DNA, RNA and protein, the sensitivities of these detection methods required the use of relatively large amount of materials. Samples containing DNA or RNA with less than 100 nanograms may not be readily visualized by the ethidium bromide staining method. Protein samples with less than micrograms of protein may not be visible in the Coomassie blue stained polyacrylamide gels. This will require the researcher to prepare more starting material and end s up in a much bigger volume that is difficult to handle. Moreover, due to the limitation of the detection chemicals the amounts of the biomolecules may not be quantified in these systems. The florescence of the ethidium bromide bound nucleic acids and the intensity of the Coomass ie blue stained proteins do not necessarily show a linear relationship with the quantity loaded into the gel. The automated electrophoresis system uses a microfluidic technology that is much more sensitive than these traditional methods. The system is able to detect as less as nanogram of DNA, RNA and protein. This is hundred times more sensitive than the conventional method. The volume required is also minimized. This will increase the accuracy of the analysis and decrease the material that is required. Moreover, the microfluidic system makes use of highly sensitive non-harmful fluorescent dyes. This allows the abundance of the individual biomolecul es to be detected and quantified. Today, we do not just talk about teaching; we will also have to talk about learning. It is necessary to provide more actual hands-on practices to the students because it can help the students to acquire and memorize the knowledge better. With the students knowing what the established methods can do, innovative and more accurate methods will be introduced for the students to compare the differences. This will train the students to learn and think more critically. In this proposal I would like to request for funding for the purchase of a microfluidic automated electrophoresis system for teaching of courses offered for the biology, biotechnology and microbiology programmes.


Project Title: IUMS 2008 XII International Congress of Bacteriology and Applied Microbiology Cloning of a putative regulator of the haloacid operon of Burkholderia cepacia MBA4
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2008
Abstract:
N/A


Project Title: Cloning and characterization of a transcriptional regulator of the haloacid operon of Burkholderia sp. MBA4
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2009
Completion Date: 12/2009
Abstract:
Burkholderia sp. MBA4 was enriched from soil using monobromoacetic acid as the sole carbon and energy source. This bacterium contains a haloacid operon, which encodes for a dehalogenase (Deh4a) and an associated permease (Deh4p). The expression of the operon has been found to be regulated. The gene products were detected only in the presence of haloacids and not when the cells were grown in pyruvate-containing or rich medium. The physical and biochemical properties of Deh4a have been well characterized and the investigation of Deh4p has also been initiated. The study on the regulation of the operon, however, is far from sufficient due to intrinsic difficulty to work on the genetics of the natural isolates. We have initiated the study by using a green fluorescent protein (GFPuv) as a report er and showed that a DNA fragment containing 100 bp of upstream non-coding sequence of the deh4a gene was sufficient for regulated expression. In silico analysis of this fragment has identified the presence of a -35 and a -10 boxes, typical of sigma-70 dependent RNA-polymerase type promoters. The use of overlapping bandshift assay showed that this 100-bp region is necessary and sufficient for the formation of retardation complexes. The biological importance of these -35 and -10 boxes was also confirmed by site-directed mutagenesis and quantitative reverse -transcriptase PCR analysis of a reporter gene. Replacement of the -10 box abolished gene expression completely. Mutation of the -35 box affected the transcriptional efficacy of the promoter. In order to obtain more information on the regulatory protein of this promoter the 100-b p fragment was ligated to form a trimer and used for making of a DNA affinity column. Cell extracts prepared from un-induced cells (grown in LB without NaCl) were fractionated by ammonium sulphate precipitation, Heparin Sepharose column and the DNA-affinity column. Fractions containing the DNA-binding ability were analyzed by SDS-PAGE gel. A 28-kDa protein was purified from the gel and digested with trypsin. The digestion products of this protein were resolved by tandem mass spectrometry and a peptide mass fingerprint was obtained. A peptide with an ion score of 100% confidence interval was also used for comparative analysis with the protein databases. The amino acids sequence of this peptide is FVLTS SVLEL SNGFL R and has been identified as part of a protein from a well-studied polychlorinated biphenyl degrader Burkholderia xenovorans LB400. This orthologous protein in LB400 has been identified as a member of the COG1414, which contains many transcriptional regulators. In this proposal I would like to clone and characterize this transcriptional regulator of the haloacid operon of Burkholderia sp. MBA4. Gene specific oligonucleotide primers will be designed according to the DNA sequences of the regulator genes in closely related species whose genomic sequences are available. These primers will then be used to amplify the corresponding gene in MBA4. The cloned gene will then be expressed in an appropriate Escherichia coli to produce sufficient amount of protein for structural and functional characterization. The expression of this regulator in MBA4 will also be investigated by quantitative reverse-transcriptase PCR to see if it were produced constitutively or in a regulated manner .


Project Title: 34th FEBS Congress Mutagenic analysis of the conserved residues of a haloacid permease
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Purification and characterization of a DNA-binding protein of a dehalogenase producing Burkholderia
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Haloacetic acids can be found in the natural environmental because of chemical and biological activities. However, most of the haloacetic acids that we detected nowada ys were produced via various human activities such as water disinfection, pesticide production and refrigerant production. Haloacetates are mutagenic and/or cytotoxic and inhibit enzyme activities in the general metabolic pathways. One of the haloacetates, monochloroacetic acid, has been used regularly in the chemical industry for making of human commodities. Monochloroacetic acid affects the citric acid cycle, gluconeogenesis and cause damages to liver and kidney. The indiscrim inate use of monochloroacetic acid has causes environmental concerns. Haloacetic acids are also produced as a result of the biodegradation of other halogenated compounds such as methyl chloride and polychlorinated biphenyls. Microorganisms have been recognized as one of the major player in remediating these harmful chemicals. Microorganisms capable of degrading these halogenated compounds usually possess an enzyme, dehalogenase, that cleaves the carbon-h alogen bond and mediate the metabolic products utilizable. The genus Burkholderia is a group of microbes with versatile metabolic capability. This group of bacteria has been found in various niches. They have been isolated as animal and plant pathogens. B. cepacia and B. cenocepac ia are clinically important species because of their association with cystic fibrosis patients. Some species have been acted as pathogen antagonists and others have been categorized as plant growth-promoting species. Many others have been isolated as important organisms responsibl e for the bioremediation of environmental pollutants. B. xenovorans LB400 has been well studied as one of the most versatile degraders that metabolize polychlorinated biphenyls. My group has been working on the degradation of halogenated alkanoic acids for many years. A Burkholder ia sp. was isolated from soil for its ability to produce a dehalogenase, Deh4a, which degrades 2-haloacids. The enzyme has been purified and the active enzyme has been found to be a dimer of 45 kDa. The gene encoding for this enzyme has been isolated and cloned into Escherichia coli. By means of domain-swap experiments with anothe r dehalogenase, the region responsible for the dimerization of the protein has been identified. Site-directed mutagenesis has also been used to find the residues essential for the structure and activity of the enzyme. A crystal structure of the enzyme has also been resolved. Since haloacetic acids are toxic it would be reasonable to assume the production of the dehalogenase as a detoxifying enzyme and, if necessary, the making of an efflux protein to decrease the availability of the compound inside the cell. During the characterization of the genomi c organization of the dehalogenase gene, we have identified the presence of an associated transporter protein gene. This permease, Deh4p, transported the haloacetic acids into the cell and the gene is located downstream of the dehalogenase gene. The gene encoding for Deh4p has been cloned and sequenced. This permease is 552 residues long and has a putative molecular weight of 59,414 and an isoelectric point of 9.14. Comparative analysis of the primary structure of Deh4p with proteins in the protein family (Pfam) database has designated it as a member of the Major Facilitator Superfamily. It looks like the dehalogenase and the permease genes form an operon responsible for the degradation and uptake of the haloacetates into the cell and converted the harmful chemicals to utilizable substrates. In order to confirm that these two genes were organized as an operon the upstream non-coding region of the dehalogenase gene has been explored. This region has the structural features of typical bacterial housing -keeping genes. Traditional -10 and -35 boxes required for the binding of a sigma-70 RNA polymerase were identified. While the expression of the gene, in multiple copies, in E. coli was minimal, it can be induced more than 200-fold by haloacetic acids in Burkholderia sp. MBA4. The gene encoding Deh4a was isolated in a 1.6-kb EcoR I fragment, which include 832 bp of upstream non-coding sequence. When this upstream sequence was truncated, progressively, and used to drive the expression of a reporter gene, it showed that 100-bp of upstream sequence is sufficient for the haloacetate induction mechanism. DNA fragment containing this 100-bp was amplified and labeled with radioisotope for electrophoretic mobility shift assay. Cell extracts were prepared from cells grown on pyruvate or monochloroacetate. The results showed the presence of retardation complex in cell extract prepared from pyruvate-grown cells and not on monochloroacetate-grown cells. This suggest ed that there is a DNA-binding protein that binds the regulatory region of the dehalogenase gene and prevented it from expressing when there were no haloacetic acids in the medium. This DNA-binding protein is most likely a repressor molecule exhibiting negative effect on the promoter. A proposal has been written and submitted to RGC for purification and characterization of this DNA-binding protein. However, the reviewers would like to see the protein purified and its DNA-binding ability confirmed. In this proposal I would like to ask for funding to purify this DNA-binding protein from MBA4. When the purified protein is available its DNA-binding ability will be confirmed by bandshift assay and the recognition-sequence/region determined by footprinting. The protein will also be subjected to tryptic digest and the digestion products analyzed by tandem mass spectrometry. This would be able to provide some preliminary information of the protein. The immediate goal is obtain sufficient background information on this molecule so that it can be cloned from MBA4 for further characteriza tion. A proposal on the cloning and characterization of this regulatory protein will be submitted to RGC for a GRF grant in 2010. The ultimate aim of the research is to understand the regulatory mechanism for the dehalogenase.


List of Research Outputs

Su X. and Tsang J.S.H. , Identification of a second haloacetic acid transporter in a haloacetate degrading bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . 2010.
Tian R. and Tsang J.S.H. , Mutagenic analysis of the upstream regulatory region of a dehalogenase gene in Burkholderia sp. MBA4, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 76.
Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.
Tsang J.S.H. and Tse Y.M. , Mutagenic analysis of the conserved residues of a haloacid permease., FEBS Journal . 2009, 276 supplement 1: 168.
Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.
Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.
Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Tse YM

List of Research Outputs

Tsang J.S.H. and Tse Y.M. , Mutagenic analysis of the conserved residues of a haloacid permease., FEBS Journal . 2009, 276 supplement 1: 168.
Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.


Researcher : Vengatesen T

Project Title: Marine calcifiers and Climate change: response of economically important juvenile benthic calcifiers to ocean acidification
Investigator(s): Vengatesen T, Williams GA, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 02/2009
Completion Date: 08/2010
Abstract:
The increase in global carbon dioxide (CO2) emis sions is not just causing global warming and climate change, but also threatening the marine organisms (Zeebe et al. 2008). CO2 emitted to the atmosphere is being absorbed by the oceans and subsequently causes not only an increase in the partial pressure of CO2 (pCO2) but also a reduction in seawater PH and carbonate ion, called “ocean acidification”. This dramatic change in seawater chemistry is likely to have a large impact on coastal productivity and biodiversity (Fabry 2008), hence assessing the impact of ocean acidification on marine organisms has been identified as a high priority (Iglesias-Rodriguez et al. 2008). The decrease in the saturation state of carbonate ions critically affects the uptake and/or dissolution of calcified shells. Marine organisms has survived large climate and acidification variations in the past, but the projected rates of climate change and ocean acidification over the next century are much faster than experienced by the planet in the past. Recent evidences from a variety of scientific disciplines indicates that calcification rates of many ecological ly important marine organisms are likely to decrease (and dissolution rates increase) in response to ocean acidification by up to 60% within this century (Hunt et al. 2008). However, these estimated rates often do not include other environmental effects (e.g., rising temperature and variable precipitation), nor do they address the effects on different life-stages or organism fitness. Over the past few years, ocean acidification effects have been investigated in very few marine organisms, e.g. corals and phytoplantons, primarily using traditional microscopic-based methods. However, recent advances in molecular biology techniques (e.g. real-time PCR, in-situ hybridization, and proteomics) now allowing us to explore physiological and molecular basis of ocean acidification effects. Majority of sessile marine invertebrates have a pelagic larval stage for dispersal and colonization of new habitats. After a period of development (from minutes to days), larvae enter a competent stage wherein they have developed the ability to attach onto substratum and metamorphose into juveniles. Larval metamorphosis and juvenile development in several species is a dynamic process (completed in few minutes) involving, tissue remodeling, and differentia tion, in addition to numerous biochemical and physiological alterations mediated by differential gene and protein expression. That is why these early-life stages are believed to be highly vulnerable to ocean acidification than their adult counterparts (Albright et al. 2008). Therefore, understanding the effects and underlying physiological and molecular basis of ocean acidificatio n on juvenile development is integral to marine ecology, fisheries biology, aquaculture and environmental biology. Current challenging questions related to ocean acidification effects on marine organisms that are related to this proposal are 1) Can early-life stages (e.g. juvenile s) adapt (e.g. by changing their calcification process) to ocean acidification over the next 100 years? 2) How does a change in calcification rate of early juvenile stages affect their metamorphic success and growth performance? and 3) How is the larval-juvenile-adult transition process mediated at acidified seawater? Answers to these questions will have far-reaching implications for fishery science, on-shore traditional aquaculture, and modeling and monitoring technology. Therefore, in the first part of this project, the effects of ocean acidification on the calcification rates of juvenile marine calcifiers will be quantitatively measured using controlled laboratory experiments. Calcified shells of marine calcifiers consist of both organic matrix materials (primarily proteins) and inorganic crystalline substances (primarily CaCO3). In fact, proteins in mineralized shells play a key role in the growth of shells and also determine the physical characteristics of shells. Besides these integral shell-proteins, calcium transport proteins (e.g. calreticulin), ion-transport membrane proteins, and signal transduction proteins are also all involved in shell formation and growth (“calcification process”). Analysis of expression response of all these proteins to ocean acidification is very crucial for our understating of organisms adaptat ion to present and predicated climate change scenarios. Recently, proteomics technology has emerged to be a highly useful tool to study protein expression pattern in whole organisms at a particular developmental stage or time (Carpentier et al. 2008). Recently, this tool has been successfully applied to marine samples (Thiyagaraja n and Qian 2008). Using similar methodology, here we will test the hypothesis that effects of ocean acidification on juvenile development are mediated through differential expression of proteins associated with calcification, metamorphosis, and stress tolerance. We are confident that this new approach will allows us to determine how juvenile stages of various marine benthic organi sms are able to biochemically cope and respond to these emerging new environmental stressors. It can also show the degree of variability in protein expression (“proteome plasticity”) to ocean acidification. Our primary objectives are: • To determine the effects of ocean acidification on juvenile stages (growth, survival, and calcification) of the economically important marine benthic organisms, and • To identify key similarities and differences in proteins relevant to calcification and/or ocean acidification stress in diverse benthic organisms (molecular mechanisms) by proteomics technology. References Albright R, Mason B, Langdon C (2008) Coral Reefs 27: 485–490 Carpentier SC, et al. (2008) Mass Spectrometry Reviews27:354–77 Fabry (2008) Science 320: 1020–1022 Hunt BPV, et al. (2008). Progress in Oceanography 78: 193–221 Iglesias-Rodriguez MD, et al. (2008) Science 320: 336–340 Thiyagarajan V, Qian PY (2008) Proteomics 8: 3164-3172 Zeebe RE, et al. (2008) Science 321: 51–52


Project Title: Physiological and molecular respon ses of the Pacific oyster larvae to ocean acidification at warm and low-saline seawater: Immediate and latent effects
Investigator(s): Vengatesen T
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To reveal the impacts of increasing pCO2, temp erature extremes and high precipitation (singly and in combination) on larvae of the commercially important shellfish; 2) To determine the long-term consequences of larval exposure to increased pCO2; 3) To test the hypothesis that exposure of larvae to increased pCO2 during mid-su mmer in Hong Kong (elevated temperature and low-salinity) would greatly negate larval metamorphic success and thus fishery; 4) To clarify the mechanisms underlying the observed physiological and ecological effects with the application of proteomics technology.


Project Title: Climate change effects on larval metamorphosis: lessons from biomineralization
Investigator(s): Vengatesen T, Shih K, Williams GA, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
The life cycle of many marine organisms includes two major stages: swimming larval and benthic (attached on hard/soft substrate) adult stage. After a period of time or attaining a physiological competency, the pelagic (swimming) larvae select a suitable habitat/substra te based on substrate properties, attach on it and then metamorphose into benthic adults (reviewed in Thiyagarajan, in press; See Fig. 2). This pelagic-benthic transition (henceforth referred to “larval metamorphosis”) is perhaps the most crucial, challenging, rapid process, involving intensive biomineralization (a process that form CaCO3 shell) and is therefore, energetically exp ensive. Larval biomineralization is one of the emerging interdisciplinary studies that examines biomaterials such as shells and skeletons produced by larval forms of marine organisms and the processes that lead to the formation of these hierarchically structured organic-inorganic composites. The biomineralization process during larval metamorphosis is not caused by adventitious precipitation; instead, it is highly regulated in a species specific manner (Gower 2008). As a consequence of natural environmental changes (e.g. rainfall), coastal regions are frequently becoming undersaturated with respect to carbonate ions, aragonite and calcite and consequently they are becoming alarmingly vulnerable to CaCO3 shell forming larvae (Findlay et al. 2009, O’Donnell et al. 2009, our studi es). Within this century, human activates (i.e. increasing CO2) are expected to exacerbate this carbonate chemistry variability (CCV). This swing in carbonate chemistry, here termed as “ocean acidification”, is relatively new to scientists and has quickly become part of global climate change issues (reviewed in Doney et al. 2009). Although this research field is rapidly advancing our knowledge, much of the available information is concerned with (1) adult organisms (rather than their larvae), (2) temperate species (subtropical climate is often neglected), (3) corals and planktonic organisms (with only few studies on calcifying shellfish), (4) calcification rates (as opposed to mechanism and biomineralization aspects), and (6) open ocean (as opposed to coastal waters) (e.g. Dupont & Thorndyke 2009). Nevertheless, the majority of these studies highlight the fact that CCV impacts are species-specific (Miller et al. 2009), larvae are more sensitive to CCV than the adults (Kurihara et al. 2009), biomineralization and skeletal structures are impaired by CCV (Cohen et al. 2009). As biomineral precipitation depends on their saturation levels, any decrease in carbonate saturation due to climate change or natural environmental change is expected to affect the ability of larvae to build their CaCO3 shells. There is an urgent need to examine this hypothetical correlation between larval metamorphosis and CCV. One of the main questions that remain to be answered is whether changes in CCV lead to significant differences in biomineralization when the magnitude of these cha nges is much smaller than the large fluctuations in CCV that occur at the site of biomineralization? Larvae of intertidal organisms (e.g. oysters and barnacles) appear very tolerant to a wide range of CCV, i.e. growth rate and developmental pattern are unaffected. Our recent work (fully funded by our ongoing HKU seed grant and partially by just awarded GRF grant) suggests, however, that physiological quality, metamorphic rate, expression of several metabolic enzymes and metamorphic success are reduced in carbonate regimes near or below aragonite saturation levels ( <Ωarag;; this level is expected in 2100 due to climate change or during heavy precipitation in summer months in Hong Kong). In such scenarios, stressed larvae ten d to uptake more CaCO3, which may impose significant costs. We, therefore, hypothesize that <Ωarag will affect larval biomineralization sequence and composition during metamorphosis, possibly through eliciting energetically costly biochemical and physiolo gical responses. According to our preliminary data, the decreasing Ωarag decreases the protein synthetic capacity and biochemical energy available for larval metamorphosis, and consequently impairing their ability to select the right substrate for attachment and metamorphosis. Therefore, we predict that the effects listed above may be due to efforts of larvae to maintain relativel y natural aragonite and/or calcite precipitation rates (biomineralization) with increased effort to cope with decreasing Ωarag . In this proposal, we will test this hypothesis using the commercial barnacle (Balanus amphitrite) by exposing their larvae to various treatments mimicki ng natural and projected carbonate chemistry regimes in Hong Kong’s coastal waters. The X-ray diffraction (XRD) microscopy is a useful technique for investigating the biomineralization process in larvae. Recently, we have been successfully using XRD to trace the composition of biominerals and their precipitation rate during larval development and metamorphosis in barnacles, green mussels and oysters (XRD patterns of swimming and metamorphosed larvae are shown in Fig. 1). This pioneering work started providing us new insight into the possible mechanisms of larval biomineralization. Through this proposal, we would proceed further to investigate the effect of CCV on the development of calcium carbonate polymorphs. Since biomineralization is genetically controlled, we hypothesize that the mineralization sequence may not be altered; however, the rate of biomineralization and the rate of mineralogical change could be affected. Since this technique (XRD) allows analysis of sample with a relatively small quantity (Medaković 2000), it would be a convenient method to detect the calcium carbonate polymorph dynamic in larval exoskeleton during their metamorphosis. To achieve our ultimate goal of understanding the causes and effects of climate change on larvae, it is essential to understand what happens to them during larval metamorph osis at biomineralization level. Also, our preliminary data and link with a crystallographer in our engineering department are tempting us to examine the larval biomineralization response to climate change. This seed grant project is designed to generate preliminary data to examine the effects as well as the mechanisms through which biomineralization in settling larvae of the commercially important and a model barnacle species, B. amphitrite, respond to environmental/climate change. Our primary objective of this proposal is to study the exceptional crystalline properties of larval CaCO3 shell, to character ize climate change variables that control their formation and composition to search for fundamental mechanisms used by early life stages of marine organisms to ongoing environmental/climate change. Specifically, 1. To determine larval metamorphic success under changing carbonate chemistry regimes (CCV) driven by natural and anthropogenic activities in coastal regions, larval attachment rate and response to natural substrates will be examined using choice bioassay method, 2. To determine larval biomineralization sensitivity/response to CCV, sequential changes in biomineral composition and their precipitation rates during larval metamorphosis will be examined using XRD.


List of Research Outputs

Li H., Vengatesen T. and Qian P.Y., Response of cyprid specific genes to natural settlement cues in the barnacle Balanus (= Amphibalanus) amphitrite , Journal of Experimental Marine Biology and Ecology . 2010, 389(1-2): 45-52.
Sun J., Zhang Y., Vengatesen T. , Qian P.Y. and Qiu J.W., Protein expression during the embryonic development of a gastropod, Proteomics . WILEY-VCH Verlag, 2010, 10(14): 2701-2711.
Vengatesen T. , A review on the role of chemical cues in habitat selection by barnacles: New insights from larval proteomics, Journal of Experimental Marine Biology and Ecology . 2010, 392: 22-36.
Vengatesen T. , Larval proteomics: a novel approach to study the effects of ocean acidification at molecular level, South China Sea Institute of Oceanology, Chinese Academy of Sciences (CAS), Guangzhou, on September 13th to 14th, 2009 . 2009.
Vengatesen T. , Lau S.C.K., Mandy T., Zhang W. and Qian P.Y., Monitoring Bacterial Biodiversity in Surface Sediment Using Terminal Restriction Fragment Length Polymorphism Analysis (T-RFLP): Application to Coastal Environment , In: A. Ishimatsu, Lie,H.J. , Coastal Environmental and Ecosystem Issues of the East China Sea . Japan, TERRAPUB and Nagasaki University, 2010, 151-163.
Vengatesen T. , Tsoi M.M.Y., Zhang W. and Qian P.Y., Temporal variation of coastal surface sediment bacte rial communities along an environmental pollution gradient, Marine environmental research . 2010, 70(1): 56-64.
Zhang Y., Sun J., Xiao K., Arellano S.M., Vengatesen T. and Qian P.Y., 2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans , Journal of Proteome Research . American Chemical Society, 2010, In press.


Researcher : Wai TC

Project Title: Stock and Ecological Status of Echinoderms in Hong Kong: Evaluation of Effectivenes s of Marine Protected Areas using Sea Urchins as Model Organism
Investigator(s): Wai TC, Ng WC, Leung KMY, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: Environment and Conservation Fund
Start Date: 04/2008
Abstract:
To conduct a comprehensive literature review of the diversity, abundance, distribution and habitat preference of echinoderm species in the Hong Kong marine environment; to conduct underwater surveys to investigate the diversity, abundance, distribution and habitat preference of commercially exploited species (Anthocidaris crassispina), and other urchin species in rocky, coral and sandy habitats; to conduct an ecological study to test the hypothesis that the number of size classes (i.e. size range) and abundance of urchin populations within MPAs are higher than those unprotected outside MPAs.


Project Title: Food source utilization of groupers (Serranidae: Epinephelinae) in rocky communities in Hong Kong: the significance of trophic subsidies to top predators
Investigator(s): Wai TC, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2009
Abstract:
Hong Kong lies on a continental shelf with mean water depth < 20m and is characterized by rocky coasts and numerous rocky islands (> 200). The long and complex coastline of Hong Kong supports a wide range of marine habitats, from soft shores at stream mouths to rocky intertida l/subtidal and coral communities, to offshore, soft-bottom communities. These habitats support a diverse fish fauna and more than 300 reef fish species have been recorded in rocky and coral communities (Sadovy and Cornish 2000). The distribution, abundance and biodiversity of fish in various marine habitats have been well-documented in recent years (Leung 1994, Leung et al. 1997, Cornish 2000a and b, Sadovy and Cornish 2000, Lam 2002, Leung 2003, Liu 2003, Qiu 2005, Situ 2007, Fok 2008) although the biology and ecology of most reef fish species are still poorly understood. Among the reef fish species in Hong Kong, many studies have focused on commercially important grouper species (Serranidae: Epinephelinae; e.g. reproductive biology, habitat assoc iation, social structure, etc; Chan and Sadovy 2002, Liu and Sadovy 2001, 2004a, 2004b, 2005, Chan unplubl) of which there are 20 species from five genera reported in Hong Kong waters. Given that heavy fishing pressure has removed most of the larger groupers (with maximum total length, TL >50cm), and that the value of live reef fish for food in local markets continues to grow (Sad ovy 1997), only relatively small species (max. TL <30cm) such as Cephalopholis boenak, Epinephelus fas ciatomaculosus, E. merra, and E. quoyanus are still commonly found in Hong Kong (Liu and Sadovy 2005, Chan unplubl). In order to conserve the remaining grouper species and manage a sustainable fish stock, in addition to studies on the population structure and reproductive biology, studies on the trophic status of fish assemblages and their associated habitats are needed to provide information on how energy flow within and between habitats will affect these fish populations (Darnaude et al. 2004, Darnaude 2005). Most species show some plasticity in their diets, which are affected by many biological and physical factors such as body size, season and habitat/region (Kulbicki et al. 2005). Although grou per species inhabiting rocky and coral habitats are presumed to be predators (Sadovy and Cornish 2000), the ontogenetic and spatial/temporal variation in prey consumption of local groupers are not known. It is hypothesized that local species will show ontogenetic shifts in diets as do other grouper species (Linde et al. 2004, Machado et al. 2008). Juvenile groupers may mainly consume small herbivores and detritivores (e.g. worms, fish and crustaceans), whilst adult groupers may rely more on large prey, which are mainly predators (e.g. cuttlefish, squids, predatory fish and crabs). The relative importance of these different trophic linkages which support grouper populations are, therefore, likely to vary with fish size. As Hong Kong experiences a monsoonal climate, the supply of food sources and the relative importance of autotrophic and detrital pathways are temporally variable on rocky coasts. In most food webs, detritus is an important energy and nutrient source for organisms via the detrital pathway, as most primary production is not consumed and is recycled and returned to the environment as detritus (Wetzel, 1995; Moore et al., 2004). Recently, the importance of detrital pathways in driving local rocky intertidal and subtidal communities has been explored using dual stable isotope ratios and fatty acid signatures as dietary tracers (Wai et al. 2008). Feeding guilds at lower trophic levels such as deposit-feeders, suspen sion-feeders and gastropod and echinoid grazers generally depend on autotrophic sources but rely much more on detrital pathways during the summer monsoon, when the availability of terrestrial-, benthic algal- and phyto-detritus peak (Wai et al. 2008). Whilst factors influencing the structure and seasonality of rocky communities in Hong Kong have been investigated (e.g. Kaehler and Williams 1996, Wai and Williams 2006, and references therein), little is known about the importance of seasonal changes and bottom-up effects of these detrital sources on production of consumers at higher trophic levels (e.g. groupers) in local rocky subtidal food webs. As only small grouper species (e.g. Cephalopholis boenak with maximum total length < 30cm) are still abundant in Hong Kong (Liu 2003, Liu and Sadovy 2005), it is hypothesized that small prey which rely on detrital pathways will be more im portant in supporting the remaining grouper populations. This project will investigate the pathways by which organic materials enter the higher trophic level of food webs in rocky communities and will elucidate the relative importance of exogenous (episodic supply of detritus) and endogenous (autotrophic) organic sources in local marine ecosystems. The main objective is to investigate the spatial and temporal variation in energy utilization of higher trophic level species, specifically grouper species in Hong Kong. This project will therefore: I. identify the potential feeding guilds consumed by local groupers; II. determine the ontogentic, spatial and temporal variation in the relative contri bution of different organic sources to groupers; III. reveal trophic pathways utilized by groupers in rocky communities. Ultimately, this project will identify the possible trophic pathways of detrital sources ut ilized by the prey of predatory fish in rocky habitats and highlight the potential importance of trophic subsidies (i.e. episodic supply of detritus) to higher trophic levels in Hong Kong marine ecosystems. This knowledge of energy transfer between and within habitats can be used to inform environmental conservation and management models of Hong Kong’s marine ecosystem. References cited: Please see additional information attached.


List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Wan JMF

Project Title: Effects of tumor necrosis factor-[alpha]TNF-[alp ha] on cyclins and related cell cycle proteins expressions in human tumor cell lines as determined
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 07/1995
Abstract:
To investigate: a) the effect of TNF on cyclins: D, E, A, B expression by flow cytometry; b) the effec t of TNF on P21, PCNA expression by cytometric studies; c) the effect of TNF on tumor cell lines proliferation and apoptosis studied by flow cytometry.


Project Title: The role of free radicals and antioxidants in motor neuron degenerative disease
Investigator(s): Wan JMF, Vacca-Galloway LL
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 07/1995
Abstract:
There are increasing evidence indicating the involveme nt of free radicals damage in many chronic diseases such as Parkinson's disease, Alzheimer's disease and neurondegenerative disease. By using a motor neuron degenerative disease mouse model, to investigate the roles of free radicals in the disease process and investigating whether antioxidants such as vitamins E and C can be any therapeutic use by naturalizing the free radicals.


Project Title: The effects of antioxidants on small cell lung cancer cell line, NCI-H446
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1995
Abstract:
Lung cancer is almost certainly the most common cancer in the world today. Over the past several years , work has focused on characterizing the prevention, inhibition and regression of lung cancer by [beta]-carotene, vitamin C and vitamin C which act as antioxidants. This study aims to investigate the antiproliferative potential of [beta]-carotene and retinoids by flow cytometry technology. The data will help us to understand how antioxidants prevent lung cancer formation and progression.


Project Title: The effects of different dietary fatty acids on the development of mammary tumors in female fischer 344 rats
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1995
Abstract:
Exciting evidences demonstrated that the quality of dietary fatty acids, especially W-6 and W-3 polyunsatura ted fatty acids affect the development of cancers such as the colon, breast, and prostate. This project aims to investigate the effect of saturated, monosaturated W-3, and W-6 polyunsaturated fatty acids on breast cancer cells proliferation by using flow cytometry technology. The data in this study will help us understand the mechanisms involved in more depth.


Project Title: Molecular Structural Determination of Protein-bound Polysaccharide peptide (PSP) isolated from the Chinese Medicinal Mushroom Coriolus versicolor (Cov-1)
Investigator(s): Wan JMF, Sze KH, Che CM
Department: Zoology
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2006
Abstract:
Purpose: The goal of this project is to determine the molecular structure of Cov-1 PSP molecule dervies from the Chinese Medicine mushroom Yun Zhi. Key Issues: Polysaccharide peptide (PSP) isolated from the mycelia of fungus Coriolus versicolor (Cov-1 str ain) or Yun Zhi is Chinese Medicine best known for its anticancer and immunomodulatory properties. PSP is classified as a biological response modifier (Ng TB 1998 review) with the ability to induce gamma-interferon, intelerukin-2 production, T-cell proliferation in cancer patients. A small peptide with a molecular weight of 16-18 kDa originating from PSP has been produced with antiproliferative and antitumor activities (Yang et al 1992). We have recently published the cellular and molecular detailed cell death induction pathways of PSP on human leukemic cells by flow cytometry (Yang &Wan 2005, Hui and Wan 2005) and cDNA arrays (Zeng, Leung &Wan 2005). The ability of the Cov-1 PSP to distinguish cancerous cells from non-cancerous cells as recently determined by us (Yang & Wan 2005) and previously by others (NT 1998 review), indeed suggesting its uniqueness potential in its development into anticancer agent. Cov-1 PSP possesses a molecular weight of approximately 100 kDa. The polysaccharide moiety is a heteropolysaccharide made up of monosccharides with alpha-1, 4 and beta-1, 3 glucosidic linkages consisting of glucose, glactose, mannose, xylose, arabinose and trace amount of rhamno se (NT 1998 review). The polypeptide unit contains glutamic and aspartic acids as the abundant amino acids. PSP is presently used as over-the-counter dietary health supplement with multiple health claims such as anti-cancer, anti-inflammatory, antioxidant, anti-allergic and ant i-viral. Our preliminary work on separation and purification of PSP by HPLC technology has identified two factions: a small molecular fraction of < 5000 Da and a macro-molecular fraction of > 5000 Da. The former fraction exhibited anticancer effect onhuman leukemia and the latter fraction exhibited immunomodulatory effect on healthy normal human T-lympho cytes. Despite the promising potentials of PSP, pharmaceumatical industry is not willing to invest into its therapeutic development unless the molecular structural information is apparent. It is urgent to identify the molecular structure of the PSP molecules as soon as possible since this unqiue Cov-1 strain medicinal mushroom exh ibits most promising anticancer and immunomodulatory properties. The Cov-1 PSP strain is currently in Phase III clinical testing for anti-cancer properties in China with sucessful outcomes. Up-to-now, there are no clear structural determination of the PSP parent molecule and its fractions. The present propoal thus sought to reveal the molecular structure of PSP. Issues to be addressed: Additional experiments are also required to more thoroughly assess the molecular structure of the compounds that are responsible for the immunomodulatory effect and that which posses anticancer activities. Purpose of this proposed project: The goal of this project is to determine the structure of Cov-1 PSP molecule by carrying out the following objectives: 1. to purify fractions of PSP by DEAE Anion-exchange HPLC system 2. to elucidate the molecular structure of PSP by spectroscpic analysi s, NMR and/or X-ray crystallograpghy. We believe that the structural determination of the molecular structure of PSP is urgently needed as to provide important insight into its distinct functions/roles in treatment of cancer and infectious diseases. References Cited: Yang MM et al (1992). The anticancer effect of a small polypeptide from Coriolus versicolor. Am J Clin Med 20: 221-32. Ng TB (1998). A review or research on the protein-bound polysaccharide PSP from the mushroom Coriolus versiolor. Gen Pharmacol 30: 1-4. Zeng F, Leung F and Wan JMF (2005). Molecular characterization of Coriolus versi color in human promyelotic leukemic HL-60 cells using cDNA microarray. In J of Oncology 26: 10-16. Hui K.P.Y& Wan JMF (2005) Induction of S phase cells arrest and caspase activation by polysaccharide peptide (PSP) isolated from coriolus versicolor enhanced the cell-cycle-dependent activity and apoptotic cell death of Doxorubicin and Etoposide but not Cytarabine in HL-60 cells. Oncology Reports. 14(1): 145-165. Yang X and Wan JMF (2005). The Cell Death Process of the Anticancer Agent Polysaccharide-peptide (PSP) in Human Promyelocytic Leukemic HL-60 Cells. Oncology Reports 13(6): 1201-1221.


Project Title: The 5th International Medicinal Mushroom Conference Polysaccaropeptide of Coriolus versicolor Enhances the Anticancer Activity of Camptorhecin (CAM) on Human :eukemic HL-60 cells
Investigator(s): Wan JMF
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 09/2009
Completion Date: 09/2009
Abstract:
N/A


List of Research Outputs

Ding W.J., Yan S.L., Zeng Y.Z., Li W.H., Duan A., Zheng T.E., Liu M., Tan C.E., Teng X. and Wan J.M.F. , Insufficient Activity of MAPK Pathway Is a Key Monitor of Kidney-Yang Deficiency Syndrome, The Journal of Alternative and Complementary Medicine . 2009, 15(6): 653-660.
Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wan J.M.F. , Sit W.H. and Yang X., Polysaccharopeptide of Coriolus versicolor enhances the Anticancer Activity of Camptothecin (CPT) on Hum an Leukemic HL-60 Cells, The 5th International medicinal Mushroom Conferen ce . 2009, 691-702.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.
Zhong W. , Sit W.H. , Wan J.M.F. and Yu A.C.H. , Sonoporation-induced apoptosis and cell-cycle arrest: initial findings, International Symposium on Therapeutic Ultrasound . 2010, D3-1.


Researcher : Wan LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.


Researcher : Wang M

Project Title: Preventive potential and mechanism of fruit phytochemicals on the formation of mutagenic heterocyclic amines
Investigator(s): Wang M
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Completion Date: 08/2009
Abstract:
To identify potent inhibitors for HA formation from pineapple and elderberry extracts using chromatog raphic and spectroscopic methods and to clarify whether their intervention can really lower overall mutagenicity in meats; to tentatively clarify the roles of several phenolic compounds in the formation of HAs and to elucidate the detailed inhibitory mechanisms involved.


Project Title: Natural tyrosinase inhibitors as skin whitening agents
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 10/2007
Abstract:
The basic aim of this study is to develop patentable tyrosinase inhibitors (purified compounds, standardi zed concentrated plant extracts) from edible and Chinese medicinal plants, and evaluate their appliction as skin whitening/lightening agents in cosmetic products.


Project Title: Natural Phenolics for Ameliorating Carbonyl Stress
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 09/2009
Abstract:
Non-enzymatic modifications of proteins have been implicated in the pathogenesis of diabetes, atherosc lerosis, and neurodegenerative diseases as well as in normal aging. The modifications can arise from direct exposure to reactive oxygen related species, chlorine, nitrogen species and from reactive with low molecular weight reactive carbonyl compounds, which originate from a multitude of mechanistically related pathways, like glycation, sugar autoxidation, lipid peroxidation and uv-photodamage. The accumulation of various reactive carbonyl species derived from either carbohydrate or lipids, as well as their subsequently induced protein modifications is proposed to constitute a state of “carbonyl stress”. It’s well known that a group of dicarbonyl compounds, including 3-deoxyglucosone (3-DG), glyoxal (GO) and methylgoxal (MGO) will be formed in Maillard reaction (glycation). The increased electrophilicity of these 1,2-dicarbonyl compounds results in their relatively fast reactions with amino, sulfhydryl and guanidine functional groups of intracellular and extracellular proteins. Lipoxidation mainly generates a burst of unsaturated aldehydes, such as 4-hydroxy-trans-2-nonenal (HNE), acrolein (ACR), and malondialdehyde (MDA). Meanti me lipoxidation is also known to produce GO. In contract to glycation-related carbonyl compounds, less is known about protein modification by lipoxidation-derived RCS. However a large body of evidence indicates that many of the effects of vascular dysfunction on cardiovascular diseases are mediated by lipid-derived RCS and the emerging role of lipid-derived RCS in hyperglycemia and in development of complication of diabetes is now well documented. Recently, the involvement of lipid-derived RCS as products and propagators of oxidative damage in neurodegenerative diseases, mainly AD, is also becoming elucidated. Under carbonyl stress, not only advanced glycation end-products (AGEs) derived from carbohydrate s but also advanced lipoxidation end-products (ALEs) derived from lipid accumulate in parallel. AGEs and ALEs might be merely end-results of protein structural modifications, alternatively they might play an active role in the development of various age-related diseases. In addition, compared to free radicals, RCS are stable and can diffuse within and even escape from cell and attack target far from the site of the original forma tion. Therefore they are not only end-products of glycation/lipoxidation, they also act as “second cytotoxic messengers”, induce different aspects of cellular stress. Thus there is a need to develop strategy to deal with carbonyl stress, to ameliorate various age-related diseases. A very limit number of inhibitors of cellular reactive carbonyl species have been identified to date and their therapeutic potential are recognized only recently. Some inhibitors interfere with the reaction by trapping carbonyl compounds, while others act merely as antioxidants and transition metal chelators. As free radicals and oxidation are known to be in the process of glycation and lipoxidation, it’s not a surprise that antioxidants may be effective in in vitro assays. However it’s questionable of the effects of antioxidant against carbonyl stress, AGE and ALE formation in the real biological system. As an example, the capability of pyridoxamine (PM) to delay development of diabetic complications in animal models has been well documented. The biological effects of PM, notably its inhibition of development of renal and vascular disorders in both diabetic and Zucker rats, may be chiefly attributable to its function as an inhibitor of AGE/ALE formation through a carbonyl-tr apping mechanism. Although PM is known to be an antioxidant, it has been shown to be incapable of preventing oxidative loss of linoleate or arachidonate in phosphate buffer, even at 1mM concentration. On the other hand, it can significantly inhibit the formation of CML, CEL and MDA-Lys, and of HNE-Lys (2-hydroxylhexanal-lysine co mplex) in the presence of ribonuclease, suggesting that it does not function primarily as an antioxidant. It is an attractive hypothesis that antioxidation may not be the dominant action mechanism of other compounds found to have inhibitory activity against AGE formation. In addition, numerous clinical trials have failed to provide conclusive evidence for the efficacy of antioxid ant therapy in several chronic diseases, questioning the effects of antioxidant against carbonyl stress. Thus the chemical agents which can directly trap reactive carbonyl species will be more promising and have real clinical application. Natural products have been shown to be safer for human consumption than synthetic compounds. In this regard, some plant extracts have been evaluated for their inhibitory effects on reactive carbonyl induced protein structural modification. However, only a very limited number of natural produ cts have been found to have reactive carbonyl-trapping capacity. Lo et al. in 2006 reported the MGO trapping reaction of green tea catechins and black tea theaflavins under simulated physiological conditions. The reaction products of EGCC and methylglyoxal were separated by chiral column and the structures were confirmed by 2D-NMR analysis. This study provided the first solid evidence that certain groups of phenolic antioxidants can directly trap reactive carbonyl species, and com pelled a reconsideration of the anti-glycation mechanism of phenolic antioxidants. The findings suggested that certain phenolics possessing dual mechanisms of action, namely antioxidation and RCS scavenging, maybe potentially more effective in preventing reactive dicarbonyl compo unds induced protein glycation. Our recent research also found procyanidin B2 can effectively trap MGO, with better trapping capacity than aminoguanidine (AG), the first AGE inhibitor explored in clinical trials. Careful examining the structures of catechins, procyanidin B2, we found they contained unique nucleophilic moiety which might contribute to their MGO trapping capacity. However little is known whether other types of phenolic compounds can trap MGO (an intermediate carbonyl compound produced during glycation) or not, and whether phenolic compounds can direct trap lipoxidation-related unsaturated carbonyl compounds or not. All these demand further scientific clarification. The basic aims of this study are to elucidate the RCS trapping capacities of various phenolic compounds, evaluation their trapping mechanism through detection of conjugated compounds and structural elucidation, and evaluation of their effects on the formation of AGEs and ALEs. In brief, the study seeks to make a significant contribution to the amelioration and prevention of several chronic diseases by discovery of specific phenolic RCS-trapping agents.


Project Title: Citrus Flavonoids as Food Additives for Reducing the Formation of Hazardous Substances in Processed Food Products
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 12/2008
Completion Date: 12/2009
Abstract:
A large portion of our disposable income is spent on food, only second to housing. Foods provide humans essential nutrients for growth and health maintenance. On the other hand, it is estimated that up to 50% of cancers are diet related. The potential harmful effects of foodborne toxicants have been well recognized. In addition to the well-known hazardous substances such as pesticides, heavy metals, antibiotics, environmental contaminants in foods, a group of compounds including heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), reactive carbonyl species (RCS), advanced glycaion end products (AGEs) and akrylamide might also contri bute to the mutagenicity, carcinogenicity and other toxic effects of certain food products. These compounds can be regarded as by-products of food heat processing, such as roasting, baking, broiling and frying, which are essential for food safety and improvement of organoleptic properties of foods. Further studies showed that fund amental food components including carbohydrates, amino acids, proteins and lipids undergo degradation, oxidation, caramelization and/or interact through Maillard reaction and various adduction reactions, giving rise to these toxicants. Mutagenicity/carcinogenicity of many of these compounds has been established. The good side is that there have been continuous research approaches aiming to reduce the formation of these compounds in foods. In the past, a combination of temperature, pH, cooking time, water activity and precursor compositions/concentration s were central determinants for the final toxic products formed. In other words, these have been targets for developing inhibitory strategies. However, the viewpoint has changed ever since the growing popularity of incorporating various food additives, plant extracts or tissues in to different cuisines and the realization of the importance of natural antioxidants in food systems. A variety of synthetic and natural agents have been examined using both simple chemical model and real food systems. The major pitfall is that most of these inhibitors were tested only for their activity against the formation of a very limited number of genotoxic substances. Consid ering the fact that the above mentioned classes of toxicants are formed from similar primary food components and that the reaction pathways, though differ, may be concurrent under many food processing conditions, it is believed that intervention with one of these pathways would have significant impact on the chemistry of others. This led us to initiate the research effort to ident ify natural additives which are active against the formation of a wide spectrum of toxic compounds formed during of thermal preparation of foods, thus minimizing the overall toxicity load of the final food products. Our recent basic research work supported by RGC has demonstra ted that certain phytochemicals can significantly inhibit the formation of mutagenic HAs in foods. One of them, naringenin, which widely occurs in citrus fruits and other plants such as tomato and apple, was found to be especially potent. Our mechanistic study has brought a new insight into the mechanism of inhibition by natural phenolic compounds, whose inhibitory mechanisms were frequently attributed to antioxidation by others. In other words, we proved that alternative key inhibitory mechanism(s) exist and the findings have been published in several top journals in the field of food science and technology. We currently has got a breakthrough discovery that naringenin probably inhibits formation of HAs, in particular, PhIP (the most abundant HA in foods) by directly trapping RCS which are critical HA intermediates. However, much further research has to be continued to realize our ultimate goal of the project – development of a commercial food additive with inhibitory activity against a broad spectrum of toxic compounds in processed foods. This will include evaluating the effect of potential flavonoids, especially naringenin, on the formation of other types of hazardous substances in foods, identification of synergistic or counteracting phytochemicals in the citrus extracts of interest, processing of by-products from citrus juice production into extracts which, ideally are to be selectively concentrated in favor of the principal inhibitors as well as synergistic components, and finally assessment of the effect of such additive on the sensory properties of the food products examined. It is hoped that commercialization of such natural extract would contribute significantly to reduction in human exposure to food-borne toxicants. The specific aims of this project are: Objective 1: Development of sensitive analytical methods for analysis of PAHs, RCS, akrylamide, and AGEs in model systems and real food products. Objective 2: Preparation of different citrus extracts using differe nt technologies and evaluating the effects of these extracts on formation of toxic substances in processed foods. Objective 3: Development of citrus extract(s) of interest into commercial food additive which is selectively concentrated in favor of potent inhibitors identified.


Project Title: The 237th ACS National Meeting & Exposition Tyrosinase inhibitors from Artocarpus heterophyllus as antibrowning agents for apple slices
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 03/2009
Abstract:
N/A


Project Title: Integrated approaches to evaluate the bioactivities of process-induced novel flavonoid derivatives in thermally processed food systems
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2009
Completion Date: 11/2010
Abstract:
Almost all food items consumed are processed to some extent. Thermal treatment is among the most popular ways of processing. During heating, a complex array of chemical reactions take place which play a pivotal role in determining the quality attributes (sensory, nutritional and safety) of the process foods. While some compounds are destroyed during food processing, many more new compounds might be introduced into the food system. Some of these compounds contribute sig nificantly to the organoleptic properties of foods, such as color and flavor. On the other hand, compounds with various biological activities could also be resulted from the heat-induced reactions. Some of them have been shown to be potential antioxidative and chemopreventive agen ts. In contrast, some are harmful and might pose significant health risks for human beings in the long term. Representative members of such food-borne toxicants include heterocycl ic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), reactive carbonyl species (RCS), advanced glycaion end products (AGEs) and acrylamide. The formation of these compounds involves complex networks of reactions, though many start with fundamental food components such as glucose, amino acids/proteins, and lipids. Other ingredients such as flavonoids may interact with these reactions. Flavonoids, in the broad sense, are virtually universal plant pigments. They are respons ible or partially responsible for the color of flowers and sometimes leaves. When they are not directly visible, they contribute to coloration by acting as copigments. Flavonoids have a common biosynthetic origin and possess the same basic structural element, namely the 2-phenylch romane skeleton. They fall into about a dozen classes depending on the degree of oxidation of the central pyran rings; best known flavonoid skeletons are flavone, flavonol, flavanone, flavan, anthocyanin and chalcone. Most of these skeletons (with the exception of anthocyanin) are quite stable. Flavonoids have been well known for their antioxidant activity. Recently, they have been recognized as a class of natural products which could be utilized to fortify various food products with powerful antioxidants either for health benefits or pure marketing strategy. In addition, flavonoids or plant extracts with high concentration of flavonoids are quite popular as novel food additives for food products to reduce the formation of mutagenic and carcinogenic heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs) and acrylamide by interaction with one key chemical reaction in food science, Maillard reaction. Our former research work has demonstrated that two flavonoids, naringenin and EGCG can significantly inhibit the format ion of mutagenic HAs in foods. Our mechanistic study has also brought a new insight into the mechanism of inhibition of HA formation by flavonoids, whose inhibitory mechanisms were frequently attributed to antioxidation. We curren tly have got a breakthrough discovery that naringenin and EGCG mainly inhibits the formation of HAs, in particular, PhIP (the most abundant HA in foods) by directly trapping Strecker aldehyde, phenylacetaldehyde which is a key intermediate PhIP formation. Novel adducts are formed between the reaction of flavonoids and phenylacetaldehyde. In case of naringenin, inhibition of PhIP formation gave rise to 8-C-(E-phenylethenyl)naringenin and 6-C-(E-phenyletheny l)naringenin in high concentrations. Independent of this, we also discover that phloridzin, a chalcone-type flavonoid and epicatecin, a flavan can effectively trap methylglyoxal, another key Maillard reactive intermediate even at room temperature to form some novel adducts. All these findings suggest that certain flavonoids could directly participate in the Maillard reaction (the reaction between sugar and amino acid/proteins, the most important chemical reaction in food), and consequently lead to the formation of flavonoid derivatives that are structurall y distinct from the parent flavonoids. It is therefore anticipated that these derivatives might have distinctive bioactivities, too. In addition, drastic heat treatment could also cause degradation of flavonoids, thus introducing further potentially bioactive compounds into the food systems concerned. Many of them will likely remain in the food products and be taken into the human body upon consumption of the food products. Ideally, these newly formed compounds could confer beneficial effects, such as enhanced antioxidant, and antimutagenic/anticarcinogeni c activities to human beings. Yet, it is probable that some of these derivatives are toxic. The impact of these thermal treatment-induced derivatives of natural products should by no means be neglected. Surprisingly, this area of enormous significance to food quality remains largely untouched. In the current study, we plan to address the above issues from a multitude of approaches: chemical, molecular pharmacological, and metabolomics approaches. With advanced analytical tools in place, we aim to characterize key thermal treatment-induced derivatives of flavonoids as well as to evaluate their biological activities. Specific objectives of this research work include: 1. Metabolomics approach to evaluate the chemical profile of the selected flavonoids in food system. Isolation and structural characterization of thermal process-induced degradation products of these flavonoids and new derivatives formed from the reaction between these flavonoids with other food ingredients, particularly formed in a few of important Maillard reaction chemical systems (glycine with glucose, phenylalanine with glucose, asparagine with glucose, and tryptophan with glucose). 2. Evaluation of the mutagenicity and toxicity of the newly formed deriva tives (adducts) or degradation products of flavonoids in different Maillard reaction systems. 3. Evaluation of antioxidant and anti-carcinogenic activities of the newly formed adducts. Their selective cytotoxicity in normal versus cancer cells will be examined, and potential anti-cancer mechanisms will be tackled with molecular approaches.


Project Title: American Chemical Society Fall 2009 National Meeting & Exposition Dietary phenolics: New roles in disease prevention and food application
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Development of Novel Skin Whitening Cosmetic Products with Natural Tyrosinase Inhibitors as Key Ingredients
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Support Programme (Tier 2)
Start Date: 04/2010
Abstract:
The basic aim of this study is to develop patentable tyrosinase inhibitors (purified compounds, standardized concentrated plant extracts) from Chinese medicinal plants, evaluate their application as skin whitening/lig htening agents in cosmetic products, and develop cosmetic formulas with these novel ingredients as key ingredients. The specific objectives are: Objective 1. To develop a highly purified and concentrated Artocarpus heterophyllus extract, with the overall content of steppogenin, artocarpesin, norartocarpetin, artocarpanone, and isoartocarpesin to reach 20%. Objective 2. To isolate, purify and elucidate the structures of tyrosinase inhibitors from Morus australis root extract and Cudrania tricuspidata twig extract and evaluate their effects on melanin synthesis and cell viability in melan-a cell culture. Objective 3. To formulate Artocarpus heterophyllus extract into real cosmetic products (cream, lotion, serum and paper mask) and test their safety, and efficacy.


Project Title: Establishing a Quality Control Platform for Popular Nutraceutical Products in Hong Kong Market
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 06/2010
Abstract:
The term "nutraceuticals" is a combination of the words nutrition and pharmaceuticals, and refers to substances which possesses physiological benefits or provides protection against chronic diseases. Nutraceu ticals may include fortified foods, functional foods, specific diets, genetically engineered foods, herbal products, dietary supplements, and processed foods such as cereals, soups, and beverages. Specific examples of nutraceutica ls are resveratrol from red grape products as an antioxidant, soluble dietary fiber products, such as psyllium seed husk for reducing hypercholesterolemia, broccoli (sulforaphane) as a cancer preventive agent, soy or clover (isoflavonoids) to improve arterial health, and vitamins and minerals for general health management. In recent years, consumers have become more health conscious. The concept of takin g nutraceuticals to promote health and prevent diseases such as heart disease, cancer, osteoporosis, arthritis, and type 2 diabetes mellitus is widely recognized. As a consequence, there has been a rapid increase in the demand for nutraceuticals which has been the major driving force for the development of nutraceutical products to suit the need of different groups of customers. The nutraceutical industry is booming and the sales of for the global nutraceutical industry is over 180 billion USD annually. There are different types and forms of nutraceuticals on the market. As for different commercial purposes, there are different quality control and quality assurance standards. But usually they follow some general rules, the raw materials must be authentic ated, safe to use, with a limit of foreign materials, heavy metals, aflatoxins and pesticides. The pH value, ash contents, moisture contents and particle size should be in a reasonable range. Also the microbiological tests must be passed. The general quality control standards are usually able to be met. But specific standards for nutraceutical products are usually lacking, and this is one of the major challenges that face the nutr aceutical industry. Instrumental methods, especially HPLC (high pressure liquid chromatography) are well known to be good methods for quality control and fingerprinting nutraceutical as well as pharmaceutical products. HPLC coupled with photodiode array detector, MS/MS and ELSD (Evaporative light scattering detector) are suitable for the analysis of various nonvolatile components in nutraceutical products and GC (Gas Chromatography) and GC/MS are good for analysis of volatile compounds, fatty acids and sterols. By careful development and validation, these instrumental methods can be used to systematically control the quality of various nutraceutical products. A recent market research pointed out that based on broad applications and increasing clinical evidence of health benefits and safety of nutraceutic als, the following types of products will likely have the best growth opportunities: soy protein nutrients; lutein, lycopene, omega-3 fatty acids, probiotics and sterol esters which can easily used as functional food and beverage additives; essential minerals calcium and magnesium; herbal extracts, garlic (for improving cardiovasc ular functions), green tea (for cancer prevention and weight loss), bilberry (for eye health), saw palmetto (for benign prostatic hyperplasia) and black cohosh (for postmentopausal symptoms); and the non-herbal extracts chondroitin, glucosamine and coenzyme Q10. In addition, global demand for nutraceutical vitamin ingredients will continue to increase. These products have already been very popular in Hong Kong and Mainland China. Together with classic Chinese healthy foods such as Reishi mushroom, bird nest, these products are the key healthy products in Hong Kong. However, in Hong Kong, we are lacking of quality control procedures and methods for these nutraceutical products, there is no lab which can perform and provide quality control analysis for them although they are very popular products in the market. This is different from the status of traditional Chinese herbal medicines, for which the government has invested a lot of resources to develop quality control procedures and this scheme has been one of major strategies for modernization of traditiona l Chinese herbal medicines. In this project, we want to establish a quality control platform for nutraceutical products. A survey of popular nutraceutical products in Hong Kong will be conducted, and methods will be developed and validated for the quality control of these products. These methods can be adopted by governmental agencies for regulation of nutraceutical products in HK, by local nutraceutical companies for production of high-quality nutraceutical products, and by the commercial testing labs in Hong Kong to provide service to local and international companies in the nutraceutical business.


List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-galla te (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neuroto xicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylam ide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Ho C.T., Sang S.M. and Wang M. , Reactive carbonyl species and advanced glycation end-products in foods, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-60 . 2010.
Law Y.K. , Wang M. , Ma D.L. , Al-Mousa F., Michelangeli F., Cheng S.H., Ng M., To K.F., Mok O.Y.F., Ko Y.Y. , Lam S.K. , Chen S.F. , Che C.M. , Chiu P. and Ko B.C.B., Alisol B, a novel inhibitor of the SERCA pump, induce s autophagy, ER-stress and apoptosis, Molecular Cancer Therapeutics . 2010, 9: 718-730.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.
Wang M. , Dietary phenolics: New roles in disease prevention and food application. , 238th ACS National Meeting, Washington, DC, United States, August 16-20 . 2009.
Wang M. , Chu I.K. and To T.K.J. , Application of epigallocatechin gallate to prevent DNA interstrand cross-links caused by reactive carbonyl species, 239th ACS national Meeting, San Francisco, CA, USA, March 21-25, AGFD-84 . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Wang Y

Project Title: EGFR Ligands in the Chicken Ovary --- How Are They Involved in the Proliferation, Differentiation, and Apoptosis of Ovarian Granulosa Cell?
Investigator(s): Wang Y, Leung FCC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2008
Abstract:
Although the actions of EGFR ligand and EGFR (EGF network) in mammalian ovary have been extensively studied (Conti et al., 2006), their roles in the ovaries of vertebrates are yet to be fully understood. Using chicken as an experimental model, the proposed project aims to address the following issues: 1) Where and when are EGFR ligands expressed in the chicken ovary? Using real-time quantitative PCR (or semi-quantitative PCR) and in situ hybridization (or immuno-histochemistry), we will examine the expressions of all EGFR ligands during (a) ovarian development, (b) prehierarchal foll icle growth and selection, and (c) rapid growth of preovulatory follicle. This experiment aims to I) provide the complete information on spatio-temporal expression pattern of ovarian EGFR ligand and II) establish a basis to inter pret the roles of EGFR ligand in the ovary. 2) What are the roles of EGF ligands in controlling granulosa cell proliferation, differentiation and apoptosis? Since mature EGFR ligands may have similar biological actions on target cells, this study will investigate their roles, particularly that of EGFR and two EGFR ligands (Epigen and HB-EGF), in granulosa cell prolifera tion, differentiation and apoptosis. a) Roles of EGFR ligand in granulosa cell proliferation, differentiation and apoptosis. In vitro evidences in chickens suggest that exogenous EGF (or TGF-α) stimulates granulosa cell proliferation and prevents its differentiation and apoptosis. However, it remains unclear if both mature and membrane-anchored forms of EGFR ligands are involved in these processes. Over-expression of chicken HB-EGF and Epigen with mutated proteolytic cleavage sites in cultured granulosa cells, together with studies on the roles of recombinant HB-EGF and Epigen, will shed light on this interesting issue. b) Roles of EGFR in granulosa cell proliferation, differ entiation and apoptosis We will knockdown the expression of EGFR by RNA interference to probe or confirm the roles of EGFR and EGFR ligand in the proliferation, differentiation and apoptosis of granulosa cells in the absence or presence of gonadotropins. Meanwhile, the inhibition of EGFR tyrosine kinase activity by Tyrphostin AG1478 will be performed to substantiate these findings. This experiment aims to address: I) whether EGFR is essential for granulosa cell proliferation, differentiation and apoptosis; II) how the EGF network and gonadotropins act in concert to determine the fate of ovarian granulosa cell. 3) Are the expressions of EGFR ligands regulated by gonadotropin and intra-ovarian factors in granulosa cell? To determine whether the EGFR ligand could mediate part of the actions of gonadotropins and local ovarian factors in granulosa cells, the regulation of EGFR ligand and EGFR expressions by gonadotropins (FSH and LH) and intra-ovarian factors (IGF-I, activ in, TGF-β1 and gonadal steroids) will be examined in cultured granulosa cells from prehierarchal and preovulatory follicles.


List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness , The 35th FEBS Congress Molecules of LIfe. June 26-July 1, 2010. . 2010.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Wang Y

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness, The 35th FEBS Congress Molecules of LIfe. June 26-July 1, 2010. . 2010.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-rela ted Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Williams GA

Project Title: Trophic links between terrestrial and marine ecosystems: the source and fate of detrital materials driving intertidal and subtidal communities
Investigator(s): Williams GA, Dudgeon D, Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2007
Abstract:
(1) Determine the spatial and temporal distribution and abundance of allochthonous detrital materials in coastal habitats. (2) Document the spatial and tempo ral variation in the relative contribution of different organic sources to both intertidal and subtidal communities. (3) Reveal the potential trophic pathways of detrital sources between terrestrial and coastal ecosystems.


Project Title: Proteomic responses of the inter tidal limpet, Cellana grata, to environmental stresses.
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2007
Completion Date: 11/2009
Abstract:
The objectives of this proposal are 1. To reveal protein profiles of intertidal limpets, Cellana grata, under extreme environmental stresses during summer low tide conditions; 2. To identify potential protein markers associated with these stresses, and elucidate the possible pathways associated with the stress response. Research Background All around the world, the intertidal zone represents a highly dynamic environmental gradient. During a tidal cycle, organisms living on this gradi ent experience the stable, buffering effects of submersion in seawater and then rapidly changing conditions when uncovered and exposed to hot, drying air (Little & Kitching, 1996). This is especially true for tropical intertidal environments, which are extremely stressful, as marine organisms have to spend part of their lives out of water under the tropical sun (Garrity, 1984). Hong Kong shores experience a monsoonal climate, and as such have a physically harsh environment, varying between cool, dry temperate winters and hot and wet tropical summers (Kaehler & Williams 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams, 1994). This kind of regular death event has not been documented on other tropical shores, although anecdot al records exist. This regular phenomenon indicates the environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. Organisms can tolerate these stressful conditions in a number of ways. If they are mobile, they can move to hide from the sun, living in refuge habitats which are damp and cool (Williams & Morritt, 1995) and timing their activity patterns to avoid stressful periods (Ng & Williams, 2006). Non-mobile species, and those mobile species which cannot find safe refuges, utilize physiological responses to minimize stresses; varying heart rate (Chelazzi et al. 1999), water evap oration (Williams & Morritt, 1995; Harper & Williams, 2001) and haemolymph osmolality (Chan et al. 2006). In extreme cases animals can adopt extreme, last-gasp responses – lifting their shells and opening their opercula to rapidly cool, but with the risk of mortality due to water loss (Williams et al. 2005). The induction and outcome of these behavioural and physiological responses are mainly driven by a series of reactions at the cellular and subcellular level. Knowledge at this level is limited and investigations have mainly focused on measurement of selected stress related proteins. One of the well known examples are the heat-shock proteins (Hsps, Feder & Hofmann, 1999; Lindquist, 1986), which have been widely studied in different taxa, habitats and localities (see Feder & Hofmann, 1999). In local investigations, we have shown species level differences in Hsp expression between limpet species, as well as variation in induction rate and timing (Lai, 2005; Dong et al. unpublished data). Further advances in our understanding of the underlying cellular mechanisms and their interactions, however, are limited by the inability to simultaneously measure multiple proteins. The development of proteomics overcomes this problem, providing a high-throughput analyzing system for rapid measurement and identification of known or unknown protein mixtures (Nunn & Timperman 2007). This allows investigators to determine how organisms are able to biochemically cope and respond to varying environmental stresses through the analysis of the expressed proteome in particular environmental conditions. Proteomics have been extensively applied in questions dealing with anthropogenic stress (e.g. pollution, see López- Barea & Gómez-Ariza 2006), although the utilization of this approach to assess natural environmental stress, particularly in marine systems, is still minor. This study is, therefore, designed to investigate, using a well-studie d and common intertidal limpet, Cellana grata, as a model organism, the proteome expression at different phases of the tidal cycle during stressful, summer spring tides. The study will identify the protein markers and pathways associated with the stress response. We plan future extension of this baseline information to other members of the intertidal community, allowing us to examine interspecific variation with respect to species’ distributions and ecologies. References: Chan BKK, Morritt D, De Pirro M, Leung KMY, Williams GA. 2006. Summer mortality: effects on the distribution and abundance of the acorn barnacle Tetraclita japonica on tropical shores. Marine Ecology Progress Series 328: 195-204 Chelazzi G, Williams GA, Gray DR. 1999. Field and laboratory measurement of heart rate in a tropical limpet, Cellana grata. Journal of Marine Biological Association of U.K. 79: 749-751. Garrity SD. 1984: Some adaptations of gastropods to physical stress on a tropical rocky shore. Ecology 65: 559–574. López-Barea J, Gómez-Ariza JL. 2006. Environmental proteomics and metallomics. Proteomics 6: S51-S62 Harper KD, Williams GA. 2001. Variation in abundance and distribution of the chiton Acanthopleura japonica and associated molluscs on a seasonal, tropical, rocky shore. Journal of Zoo logy 253:293-300 Kaehler S, Williams GA. 1996. Distribution of algae on tropical rocky shores: spatial and temporal patterns of non-coralline encrusting algae in Hong Kong. Marine Biology 125: 177-187 Lai CH. 2005. Heat shock protein expression in limpets on Hong Kong rocky shores. M.Phil thesis. The University of Hong Kong. Hong Kong. Little, C, Kitching, J. 1996. The Biology of Rocky Shores. New York: Oxford University Press Ng JSS, Williams GA. 2006. Intraspecific variation in foraging behaviour: influence of shore height on temporal organization of activity in the chiton Acanthopleura japonica. Marine Ecology Progress Series 321: 183-192 Nunn BL, Timperman AT. 2007. Marine proteomics. Marine Ecolo gy Progress Series 332: 281-289 Sanders BM, Hope C, Pascoe VM, Martin LS. 1991. Characterization of the stress protein response in two species of Collisella limpets with different temperature tolerance. Physiological Zoology 64: 1471-1489 Williams GA. 1994. The relationship between shade and molluscan grazing in structuring communities on a moderately-exposed tropical rocky shore. Journal of Experimental Marine Biology and Ecolo gy 178: 79-95 Williams GA, Morritt D. 1995. Habitat partitioning and thermal tolerance in a tropical limpet, Cellana grata. Marine Ecology-Progress Series 124:89-103. Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Physiolo gical responses to heat stress on a tropical shore: the benefits of mushrooming behaviour in the limpet Cellana grata. Marine Ecology Progress Series 292: 213-224


Project Title: Comparative proteomic responses of the intertidal limpet, Cellana grata, to heat and hypo-osmotic stress: a laboratory verification
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2008
Completion Date: 05/2010
Abstract:
The objectives of this proposal are 1. To reveal protein profiles and identify potential protein markers of intertidal limpets under heat and rain stress and 2. elucidate the possible pathways associated with these physiological responses. Research Background Located at the fringe of terrestrial and marine environments, the intertidal zone inherits extreme environmental conditions from both sources. Over a tidal cycle, organisms living on this gradient experience cool, high salinity seawater during submergence, followed by rapidly changing conditions when uncovered and exposed to hot, drying air (Little & Kitching, 1996). During emergence, individuals may also experience rainfall, resulting in these marine organisms being stressed from immersion in freshwater (Morritt et al, 2007). Such a situation is especially true in tropical intertidal environments, which are extremely stressful due to high temperatures (air temperatures > 35 ºC) and monsoonal rains in the summer months (Garrity, 1984). More impo rtantly, the extent and frequency of these extreme environmental conditions is expected to be exacerbated based on climate change projections of elevated temperature (+3.3 ºC by 2100 in East Asia) and precipitation (+9% by 2100 in East Asia, IPCC 2007). Hong Kong shores experience such a monsoonal climate, and therefore have a physically harsh environment, varying between cool, dry almost temperate winters and hot and wet tropical summers (Kaehler & Williams 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams 1994; Williams et al. unpublished data, where > 50% of all individuals on a shore can be killed). This mass mortality is known to be associated with heat and desiccation stress during hot, summer low tides (Garrity 1984, Williams et al. 2005). Interspersed among these hot desiccating conditions (when animals experience hyper-osmotic stress due to dehydration), the intertidal biota are also stressed by intensive monsoonal rains which can exceed 500mm per day or >100mm per hour (Hong Kong Observatory ) and which result in hypo-osmotic stress (Morritt et al. 2007). This regular phenomenon illustrates that environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of many intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. To survive these environmental stresses, organisms can perform a number of behavioural or physiological strategies. If they are mobile, th ey can avoid excess heat by hiding from the sun, living in refuge habitats which are damp and cool (Williams & Morritt, 1995) and timing their activity patterns to avoid stressful periods (Ng & Williams, 2006). Non-mobile species, and those mobile species which cannot find safe refuges, utilize physiological responses to minimize stresses; varying heart rate (Chelazzi et al. 1999), water evaporation (Williams & Morritt, 1995; Harper & Williams, 2001) and haemolymph osmolality (Chan et al. 2006). In extreme cases animals can adop t final, last-gasp, responses – lifting their shells or opening their opercula to rapidly cool, but with the risk of mortality due to water loss (Williams et al. 2005). To cope with osmotic stress, marine invertebrates can handle moderate salinity change by cell volume regulation involving changes in intracellular amino acid and inorganic ion concentrations (Gainey 1994). In the case of prolonged / intensive hypo-saline exposure, animals often resort to “behavioural osmoregulation” whereby they isolate their soft tissue from the osmotically stressful environment, such as shutting the valves in bivalves or in snails by closing their aperture with their operculum. Such behavioural isolation, however, can often only be sustained for a short-time due to the expenses of depressed metabolism and adverse physiol ogical effects (Sokolova et al. 2000). The induction and outcome of these behavioural and physiological responses are mainly driven by a series of reactions at the cellular and subcellular level. Knowledge at this level is limited and investigations have mainly focused on meas urement of selected stress related proteins. The development of proteomics overcomes this problem, providing a high-throughput analyzing system for rapid measurement and identification of known or unknown protein mixtures (Nunn & Timperman 2007). This allows investigators to determine how organisms are able to biochemically cope and respond to varying environmental stresses through the analysis of the expressed proteome in particular environmental conditions. This study is, therefore, designed to investigate, using a well-studied and common intertid al limpet, Cellana grata, as a model organism, the physiological responses and proteome expression under laboratory controlled heat and rain stresses. The study will specifically identify the protein markers and pathways associated with the stress response. We plan future extension of this baseline information to other members of the intertidal community, allowing us to examine interspecific variation with respect to species’ distributions and ecologies. References: Chan BKK, Morritt D, De Pirro M, Leung KMY, Williams GA. 2006. Marine Ecology Progress Series 328: 195-204 Chelazzi G, Williams GA, Gray DR. 1999. Journal of Marine Biological Association of U.K. 79: 749-751. Gainey LF. 1994. Journal of Experimental Marine Biology and Ecology 181:201-21 Garrity SD. 1984: Ecology 65: 559–574. Harper KD, Williams GA. 2001. Journal of Zoology 253:293-300 Hong Kong Observatory Monthly meteorological normals and extremes for Hong Kong. http://www.hko.gov.hk/wxinfo/climat/normals.ht m. IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marqui s, K.B. Avery, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. Kaehler S, Williams GA. 1996. Marine Biology 125: 177-187 Little, C, Kitching, J. 1996. The Biology of Rocky Shores. New York: Oxford University Press Morritt D, Leung KMY, De Pirro Maurizio, Yau C, Wai TC, Williams GA (2007) Journal of Experime ntal Marine Biology and Ecology 352: 78-88 Ng JSS, Williams GA. 2006. Marine Ecology Progress Series 321: 183-192 Nunn BL, Timperman AT. 2007. Marine Ecology Progress Series 332: 281-289 Sanders BM, Hope C, Pascoe VM, Martin LS. 1991. Physiological Zoology 64: 1471-1489 Sokolova, I.M., Bock, C., Pörtner, H.-O., 2000. Journal of Comparative Physiology B 170: 91–103 Williams GA. 1994. Journal of Experimental Marine Biology and Ecology 178: 79-95 Williams GA, Morritt D. 1995. Marine Ecology-Progress Series 124:89-103. Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Marine Ecology Progress Series 292: 213-224


Project Title: Effect of metabolic rate regulation on heat shock response of the high shore snail Echinolit torina malaccana
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2009
Abstract:
The objectives of this proposal are 1. To investigate the physiological response (heart rate) of Echinolittorina malaccana to thermal stress under different metabolic states (active, short and long aestivation periods) 2. To investigate the expression profile of HSP70 during thermal stress and recovery phases. 3. To link HSP70 expression to physiological response shown to thermal stress at the different metabolic states Research Background Located at the fringe of terrestrial and marine environments, the intertidal zone inherits extreme environmental conditions from both sources. Over a tidal cycle, organisms living on this gradient experience cool, high salinity seawater during submergence, followed by rapidly changing conditions when uncovered and exposed to hot, drying air (Little et al., 2009). Hong Kong shores experience such a monsoonal climate, and therefore have a physically harsh environment, varying between cool, dry almost temperate winters and hot and wet tropical summers (Kaehler & Williams, 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams 1994; Firth and Williams, 2009; Willi ams et al. unpublished data, where > 50% of all individuals on a shore can be killed). This mass mortality is known to be associated with heat and desiccation stress during hot, summer low tides (Williams et al. 2005). This regular phenomenon illustrates that environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of many intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. Species living at the upper intertidal zone, encounter a more prolonged emersion period which can extend to days or weeks without supply of sea water, depending on the tidal regime. These animals may undergo metabolic rate depression in order to reduce energy consumption, as well as to avoid excessive thermal and hypoxic stress (Storey & Storey 1990). Upon the metabolic rate depression or aestivation, animals undergo a series of internal physiological processes to reduce energy-producing and energy consuming reactions and marine molluscs are known to be able to depress metabolic rates by 70 to 98%. The snail Echinolittorina malaccana is a common intertidal grazer at the upper littoral zone of Western Pacific rocky shores. This species has a wide geographic distribution along the Indo-West Pacific from temperate to tropical regions in both hemispheres (~30°N to 25ºS), and longitudinally from the east Australian coast in the east to the Indian coast on the west (Reid 2006). As such this species is an ideal model organism to investigate potential variation in physiological responses in a single species over a wide range of environmental conditions, with a view to understanding if tolerances of the same specie s may vary over latitudinal gradients in association with climatic conditions. This species is dominant on Hong Kong shores where it is an important grazer of the epilithic biofilm (Mak & Williams, 1999). It is the highest vertically distributed marine gastropod on Hong Kong shores and can survive for weeks without immersion (Uglow & Williams, 2001), as such it should experience the most harsh environmental conditions of all intertidal species. Metabolic rate depression in littorinids is known to be an important physiologica l response, with evidence of suppression of heart rate and oxygen consumption (Marshall unpublished data). In Echinolittorina malaccana, depression in metabolic rate is triggered by prolonged emersion and metabolic rate can be reduced to 20% when snails adopt a state of aestivation as compared with their normal active state. The differential physiological response to thermal stress in the normal and aestivation state, however, has never been reported in this and other taxa with a similar capacity of metabolic regulation. Of the potential physiological responses, the production of specific stress compensating proteins is a widely adopted strategy. Heat shock proteins (HSPs) are a class of functionally related proteins whose expression is increased when cells are exposed to elevated temperatures or other stress (Abe & Latchm an 1999). Among the HSPs, HSP70 is an important protein which takes part in the cell's machinery for protein folding, and helps to protect cells from stress. Its expression with respect to thermal stress has been well characterized in local intertidal animals (Lai 2005), and is considered suitable to quantify the level of stress response in gastropods (Dong et al 2008) This study is, therefore, designed to investigate, using Echinolittorina malaccana as a model organism, the potential responses to laboratory controlled heat stress under different metabolic states (active, short-term and long-term aestivation). Considering the wide geographic distribution of the species, the findings of this study will form the base for future extension to conspecifi cs located along similar latitudinal distribution, allowing us to evaluate the intraspecific plasticity of the stress response and the potential differential effect of temperature change on species biogeography. References: Abe H, Latchman DS. 1999. Stress proteins. Springer, New York. Dong YW, Miller LP, Sanders JG, Somero GN 2008. Heat-shock protein 70 (Hsp70) expression in four limpets of the genus Lottia: Interspecific variation in constitutive and inducible synthesis correlates with in situ exposure to heat stress. Biological Bulletin 215:173-181 Firth LB, Williams GA. 2009. The influence of multiple environmental stressors on the limpet Cellana toreuma during the summer monsoon season in Hong Kong. Journal of Experim ental Marine Biology and Ecology (in press) Chelazzi G, Williams GA, Gray DR. 1999. Field and laboratory measurement of heart rate in a tropical limpet, Cellana grata. Journal of Marine Biological Association of U.K. 79: 749-751. Kaehler S, Williams GA. 1996. Distribution of algae on tropical rocky shores: spatial and temporal patterns of non-coralline encrusting algae in Hong Kong. Marine Biology 125: 177-187 Lai CH. 2005. Heat shock protein expression in limpets on Hong Kong rocky shores. M.Phil thesis. The University of Hong Kong. Hong Kong. Little, C, Williams GA, Trowbridge C 2009 The Biology of Rocky Shores. 2nd Edition: Oxford University Press Mak, YM, Williams GA 1999 Littorinids control high intertidal biofilm abundance on tropical, Hong Kong rocky shores. Journal of Experimental Marine Biol ogy and Ecology 233:81-94 Reid DG, Lal K, Mackenzie-Dodds J, Kaligis F, Littlewood DTJ, Williams ST 2006 Comparative phylogeography and species boundaries in Echinolittorina snails in the central Indo-West Pacific. Journal of Biogeography 33:990–1006 Storey KB, Storey JM. 1990. Metabolic rate depression and biochemical adaptation in anaerobiosis, hibernation and estivation. The Quarterly Review of Biology 65:145-174 Uglow RF, Williams GA. 2001. The effects of emersion on ammonia efflux of three Hong Kong Nodilittorina species. Journal of Shellfish Research 20:489–493 Williams GA. 1994. The relationship between shade and molluscan grazing in structuring communities on a moderately-exposed tropical rocky shore. Journal of Experimental Marine Biology and Ecology 178: 79-95 Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Physiological responses to heat stress on a tropical shore: the benefits of mushrooming behaviour in the limpet Cellana grata. Marine Ecology Progress Series 292: 213-224


List of Research Outputs

Firth L.B. and Williams G.A. , The influence of multiple environmental stressors on the limpet Cellana toreuma during the summer monsoon season in Hong Kong, Journal of Experimental Marine Biology and Ecology . 2009, 375: 70-75.
Ng W.C. , Leung T.Y. and Williams G.A. , Comparative proteomic responses in two intertidal limpets (Cellana grata and Cellana toreuma) to summer low tides on tropical rocky shores, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limp et Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Poon D., Chan K.K. and Williams G.A. , Spatial and temporal variation in the diets of the crabs Metopograpsus frontalis (Grapsidae) and Perisesarma bidens (Sesarmidae): implications for mangrove food webs., Hydrobiologia . 2010, 638: 29-40.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Williams G.A. , Guest Professor, Xiamen University, China . 2009.


Researcher : Wong AOL

Project Title: Novel actions of somatostatin in grass carp pituitary cells: inhibition of growth hormone synthesis through up-regulation of CREB Gene expression
Investigator(s): Wong AOL
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2006
Completion Date: 12/2009
Abstract:
To demonstrate the presence of somatostatin (SRIF) immunoreactivity in the grass carp pituitary; to confirm that SRIF can inhibit GH production and GH gene expression in grass carp pituitary cells; to test if SRIF can interact with other GH-releasing factors to regulate GH gene expression at the pituitary level; to study the role of GH transcript stability and gene transcription in SRIF inhibition of GH mRNA expression; to test if SRIF can modulate CREB production and CREB gene express ion in grass carp pituitary cells; to examine the role of transcript stability and gene transcription in SRIF-induced CREB mRNA expression; to check for spatial and temporal correlations between CREB and GH mRNA expression after SRIF treatment; to elucidate the post-receptor signa ling events mediating SRIF actions on CREB and GH mRNA expression; to test if SRIF treatment and CREB over-expression can affect the promoter activity of grass carp GH gene; to map the location(s) of SRIF and CREB responsive sequence(s) in grass carp GH promoter by 5' deletion; to identify the cis-acting element(s) in GH promoter for SRIF and CREB regulation of GH gene transcription.


Project Title: CREB co-ordinates the differential actions of c-Fos and Jun-B in PACAP-induced growth hormone gene expression in grass carp.
Investigator(s): Wong AOL
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2007
Abstract:
To establish the spatial and temporal correlation of c-Fos and Jun-B expression with PACAP-induced CREB phosphorylation & GH gene expression in carp somatotrophs; to elucidate the functional role of cAMP/PKA, PLC/PKC, Ca2+/CaM cascades in PACAP-stimulated c-Fos and Jun-B gene expression in carp somatotrophs; to characterize the genomic organization and 5’promoters of grass carp c-Fos and Jun-B genes by molecular cloning and sequence matching; to confirm that c-Fos and Jun-B promoters can be activated by PACAP through appropriate signaling mechanisms and CREB phosphorylation; to test the functi onal role of CRE sites in c-Fos and Jun-B promoters in PACAP-induced c-Fos & Jun-B gene transcription via CREB activation.


Project Title: Pituitary D1/D1A Receptor in Dop amine-Stimulated Growth Hormone Gene Expression in Grass Carp.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To establish the structural identity of grass carp D1/D1A receptor by molecular cloning and confirm its expression in carp somatotrophs isolated by laser capture microdissection; (2) To characterize the rece ptor binding specificity and functional properties of grass carp D1/D1A receptor by expression studies in mammalian cell line; (3) To examine the local actions of GH and LH on both basal as well as DA D1-stimulated D1/D1A gene expression in carp somatotrophs; (4) To elucidate the functional coupling of the cAMP/PKA pathway with MAPK- and PI3K-dependent cascades in DA D1-stimulated GH gene expression in grass carp pituitary cells; (5) To unveil the functional role of cAMP/PKA-, ERK1/2-, P38 MAPK-, and PI3K-dependent cascades and CREB phosphorylation in DA induction of GH promoter activity through D1/D1A receptors.


Project Title: Negative Modulation of Intrapituitary Feedback Loop in Grass Carp by Insulin-like Growth Factors through down-regulation of pituitary growth hormone receptor expression.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To establish the structural identity of IGF-I & -II expressed in the carp pituitary and characterize their expression patterns in different pituitary cell types; 2) To examine the local actions of LH and GH on IGF-I & -II expression in grass carp pituitary cells, both at the transcript level and protein level; 3) To confirm the functional involvement of locally produced IGFs in LH- and GH-induced GHR down-regulation in ca rp pituitary cells; 4) To elucidate the functional role of ERK1/2-, P38 MAPK-, JNK- and PI3K-dependent cascades in IGF-I & -II modulation of GHR mRNA & protein expression in carp somatotrophs.


Project Title: The 92th Annual Meeting & Expo of the Endocrine Society (ENDO 2010) Functional Interactions of Activin with PACAP and GnRH in regulating Grass Carp LH beta Gene Transcription.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Huo L. and Wong A.O.L. , structure and transcriptional regulation of grass carp calmodulin gene. , Biochem Biophys Res Commun . 2009, 390: 827-833.
Wong A.O.L. , Award for Teaching Excellence (2009, HK$20,000), Faculty of Sciences, University of Hong Kong . 2009.
Wong A.O.L. , GRF Merit Award (2008, HK$50,000), University Research Committee, Univeristy of Hong Kong . 2009.
Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeti ng of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Wong AST

Project Title: Outstanding Young Researcher Award 2006-2007
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Young Researcher Award
Start Date: 11/2007
Abstract:
Nil


Project Title: The molecular basis of anoikis resistance in ovarian cancer cells.
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 10/2008
Completion Date: 09/2009
Abstract:
Ovarian cancer is a highly metastatic cancer charac terized by widespread peritoneal dissemination and ascites formation, which constitute the major cause of death in ovarian cancer patients. Current therapeutic approaches for advanced-stage or metastatic ovarian cancer have little effect and the five-year survival rates of this group of patients are only 16-28% (1). Thus, there is a need for new therapeutic targets and a better understanding of the molecular mechanisms underlying the progression of ovarian cancer. In addition to gaining functions of invasion, cell resistance to anoikis plays an important role in tumor progression and metastasis as tumor cells lose matrix attachment during metastasis (2). Anoikis, also known as suspension-induced apoptos is, is a term used to describe programmed cell death (apoptosis) of epithelial cells induced by loss of matrix attachment (2). This process is particularly relevant to ovarian cancer as unlike many tumors, ovarian cancer metastasi ze by peritoneal dissemination where tumor cells lack appropriate cell matrix contacts while in ascitic fluid during metastasis. Thus, new findings involved in the regulation of anoikis in human tumor cells may provide new insight into mechanism of tumor metastasis. However, although significant progress has been made in understan ding apoptotic signaling, little is known regarding regulation of anoikis by growth factors. Moreover, many studies on anoikis are performed in primary or immortalized rodent cells, which may be irrelevant to human cancers. We and others have demonstrated that the expression of hepatocyte growth factor (HGF) and its receptor Met play an important role in ovarian tumor progress ion and metastasis. Met is found to be overexpressed in ovarian cancer and its expression is inversely correlated with patients' survival (3-5). HGF is significantly increased in ovarian cancer ascites and cystic fluids (6, 7). HGF strongly induces proliferation, migration, and invasion of ovarian cancer cells (6, 8-10). Moreover, blocking the HGF effects using monoclonal antibodies or antagonistic framents, or inhibiting Met by siRNA abrogates ovarian cancer cell migration in vitro and delays intraperitoneal tumor growth and dissemination in vivo (5, 11, 12). Upon HGF stimulation, Met activates multiple downstream signals through its multifunctional docking site located at its carboxyl-terminal tail. A wide range of signal transducers involved in cell motility induced by HGF have been identified in several cell lines. However, the contribution of signaling pathway triggered by Met appears to be highly dependent on the cellular context. Because HGF-Met signaling is clinically associated with metastasis of ovarian cancer cells, we performed experiments to determine whether HGF provides protection against apoptosis induced by a loss of matrix attachment, and the molecular mech anisms underlying this process. References: 1. Tingulstad S, Skjeldestad FE, Halvorsen TB, Hagen B. Survival and prognostic factors in patients with ovarian cancer. Obstet Gynecol 2003;101:885-891. 2. Frisch SM, Screaton RA. Anoikis mechanisms. Curr Opin Cell Biol 2001;13:555 -562. 3. Di Renzo MF, Olivero M, Katsaros D, Crepaldi T, Gaglia P, Zola P, Sismondi P, Comoglio PM. Overexpression of the Met/HGF receptor in ovarian cancer. Int J Cancer 1994;58:658-662. 4. Huntsman D, Resau JH, Klineberg E, Auersperg N. Comparison of c-met expression in ovaria n epithelial tumors and normal epithelia of the female reproductive tract by quantitative laser scan microscopy. Am J Pathol 1999;155:343-348. 5. Sawada K, Radjabi AR, Shinomiya N, Kistner E, Kenny H, Becker AR, Turkyilmaz MA, Salgia R, Yamada SD, Vande Woude GF, Tretiakova MS, Lengyel E. c-Met overexpression is a prognostic factor in ovarian cancer and an effective target for inhibition of peritoneal dissemination and invasion. Cancer Res 2007;67:1670-1679. 6. Corps AN, Sowter HM, Smith SK. Hepatocyte growth factor stimulates motility, chemotaxis and mitogenesis in ovarian carcinoma cells expressing high levels of c-met. Int J Cancer 1997;73:151-155. 7. Baykal C, Demirtaş E, Al A, Ayhan A, Yüce K, Tulunay G, Köse MF, Ayhan A. Comparison of hepatocyte growth factor levels of epithelial ovarian cancer cyst fluids with benign ovarian cysts. Int J Gynecol Cancer 2004;14:152-156. 8. Wong AS, Roskelley CD, Pelech S, Miller D, Leung PC, Auersperg N. Progressive changes in Met-dependent signaling in a human ovarian surface epithelial model of malignant transformation. Exp Cell Res 2004;299:248-256. 9. Zhou HY, Wong AS. Activation of p70S6K induces expression of matrix metalloproteinase 9 associated with hepatocyte growth factor-mediated invasion in human ovarian cancer cells. Endocrinology 2006;147:2557-2566. 10. Zhou HY, Pon YL, Wong AS. Synergistic effects of epidermal growth factor and hepatocyte growth factor on human ovarian cancer cell invasion and migration: role of extracellular signal-regulated kinase 1/2 and p38 mitogen-act ivated protein kinase. Endocrinology 2007;148:5195-5208. 11. Sowter HM, Corps AN, Smith SK. Hepatocyte growth factor (HGF) in ovarian epithelial tumour fluids stimulates the migration of ovarian carcinoma cells. Int J Cancer 1999;83:476-480. 12. Saga Y, Mizukami H, Suzuki M, Urabe M, Kume A, Nakamura T, Sato I, Ozawa K. Expressi on of HGF/NK4 in ovarian cancer cells suppresses intraperitoneal dissemination and extends host survival. Gene Ther 2001;8:1450-1455.


Project Title: Role of GnRH in ovarian cancer metastasis
Investigator(s): Wong AST, Cheung ANY, Lin MC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To determine if the presence of P-cadherin is necessary to facilitate peritoneal adhesion, and elucidate the signaling mechanism of P-cadherin that promotes GnRH-mediated cell invasion and motility; (2) To determine whether GnRH mediates adhesion and invasion of ovarian cancer cells to the peritoneal ECM through an integrin-mediated mechanism.


Project Title: Cross-talk between estrogen-related receptor alpha and beta-catenin signaling in ovarian cancer
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2010
Abstract:
Key issues and problems being addressed: Ovarian cancer is, after breast cancer, the second most common gynecological cancer, but has the highest mortality of all the gynecological cancers in Hong Kong and China (Hong Kong Cancer Registry). It is also the leading cause of death from gynecolgoical neoplasms in North America and Europe (1). Worldwide, it is estimated that there are ~200,000 new cases per year (equivalent to 1 new case every 2 minutes). Current therapies have little effect, with poor 5-year survival rates of only 16-28%. Despite its clinical significance, the mechanisms underlying the development and progression of ovarian cancer are among the least understood of all major human malignancies. Therefore, there is a need for new therapeutic targets and a better understanding of the molecular basis of the pathogenesis of ovarian cancer. b-catenin has a dual role in cell-cell adhesion and signaling. b-catenin is mainly localized at the plasma membrane of adherens junctions where it binds E-cadherin, which plays an important role in maintaining normal tissue architecture and contact inhibition. In contrast, free b-catenin in the cytoplasm is a key regulator of cell proliferation, survival, and cell cycle control (3). Free, cytoplasmic b-catenin is a critical point in Wnt/b-catenin signaling. It is because free b-catenin in the cytoplasm can translocate to the nucleus where it binds to transcription factors, including TCF/LEF, and stimulate transcription of the target genes that direct cell fate (4). Therefore, in normal cells, the protein levels of free b-catenin are tightly regulated. During tumorigenesis, there is a high frequency of mutations in key genes constituting the pathways, such as APC, Axin, and b-catenin itself. Deregulation of b-catenin signaling has been detected in a number of malignancies, such as colon cancer, melanoma, hepatocellular carcinoma, ovarian cancer, breast cancer, and prostate cancer (4). Therefore, understanding its regulatory mechanisms in cancer is very intriguing and worth further investigation. This knowledge is important for understanding the cancer disease process and may be significant for cancer treatment and prevention. The recent discovery of members of the nuclear receptor family, such as androgen receptor (AR), retinoic acid receptor (RAR), retinoid X receptor (RXR), glucocorticoid receptor (GR), thyroid receptor (TR), vitamin D receptor (VDR), estrogen receptor (ER ), and peroxisome proliferator-activated receptor (PPAR) (5), can interact with b-catenin and modulate its signaling brings new hope to cancer patients. It is because the interaction between nuclear receptors and b-catenin does not depend on the Wnts. Therefore, even in the presence of various mutations in the Wnt pathway, such cross-talk can also occur to regulate b-catenin turno ver, suggesting a new direction in cancer therapy. There are many mechanisms that nuclear receptors can regulate Wnt/b-catenin signaling. For example, the cross-talk between AR, RAR, VDR and b-catenin was found to inhibit b-catenin transcriptional activation and thereby tumor formation (5). PPAR has been shown to increase the expression of PTEN to regulate b-catenin degradation via GSK3b. These processes can be regulated by the small molecule ligands. Therefore, understanding the cross-talk regulation between nuclear receptor and Wnt/b-catenin can help compound screening for new cancer drug discovery. Estrogen-related receptor alpha (ERRa), a unique member of the orpha nuclear receptor superfamily, was recently implicated in ovarian tumorigenesis, with its expression being the highest in malignant tumors (6). ERRa plays a pivotal role in the regulat ion of cell proliferation and apoptosis and is therefore an important molecular target in ovarian cancer. Moreover, although more than two thirds of ovarian cancers express estrogen receptor (ER), only a minor proportion of patients (7-18%) respond clinically to anti-estrogen treatment. It has been suggested that ERRa may be part of the explanation for the common resistance of ovarian cancer to ER blockade. Purpose of the proposed project: Recently, we show that b-catenin is a key regulator of the cellular apoptosis in human OSE and ovarian cancer cells. (7). In our preliminary study, we show for the first time that the expression of b-catenin can be regulated by ERRa. Using an in vitro transfection approach, we showed that overexpression of ERRa stro ngly inhibited b-catenin expression, indicating that ERRa can negatively regulate b-catenin activity. Furthermore, the expression pattern of ERRa in ovarian cancer appears to be opposite to b-catenin expression (8). These findings are very interesting and led us to hypothesize that ERRa may serve as a novel negative regulator of b-catenin signaling, and that ERRa inhibition of b-catenin signaling may promote the development and progression of ovarian cancer cells by stimulating cell proliferation and/or preventing apoptosis. Unraveling the molecular mechan isms underlying the cross-talk between ERRa and b-catenin signaling will help us to understand the pathogenesis of ovarian cancer and to develop novel therapeutics for ovarian cancer. In this proposal, we aim to characterize the ERRa/b-catenin cross-talk and its implication in ovarian cancer prevention and treatment. Research objectives: 1) To investigate the correlation between ERRa and b-catenin expression and distributi on in the development and progression of ovarian cancer. 2) To determine the mechanisms by which ERRa regulates b-catenin expression and signaling. References 1. Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer Statistics, 2009. CA Cancer J Clin 2009;59:225-49. 2. Auersperg N, Wong AS, Choi KC, Kang SK, Leung PC. Ovar ian surface epithelium: biology, endocrinology, and pathology. Endocr Rev 2001;22:255-88. 3. Bienz M. beta-Catenin: a pivot between cell adhesion and Wnt signalling. Curr Biol 2005;15:R64-7.. 4. Peifer, P, Polakis P. Wnt signaling in oncogenesis and embryogenesis - a look outside the nucleus. Science 287;1606-9. 5. Mulholland DJ, Dedhar S, Coetzee GA, Nelson CC. Interaction of nuclear receptors with the Wnt/beta-catenin/Tcf signaling axis: Wnt you like to know? Endocr Rev 2005;26: 898-915. 6. Stein RA, McDonnell DP. Estrogen-related receptor alpha as a therapeutic target in cancer. Endocr Relat Cancer 2006;13:S25-32. 7. Pon YL, Wong AS. Gonadotropin-induced apoptosis in human ovarian surface epithelial cells is associated with cyclooxygenase-2 up-regulation via the beta-catenin/T-cell factor signaling pathway. Mol Endocrinol 2006;20:3336-50. 8. Cheung LW, Ip CK, Wong AS. Cadherins and signaling in ovarian cancer progression . In: Cancer Metastasis - Biology & Treatment, Springer Life Sciences (in press).


Project Title: Involvement of orphan nuclear receptor Nurr77 in regulating β-catenin turnover and signaling
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: NSFC/RGC Joint Research Scheme
Start Date: 01/2010
Abstract:
To investigate the correlation between Nur77 and b-catenin expression and distribution in colon cancer specimens, and its potential significance in the development and progression of colon cancer; to investigate the mechanisms by which Nur77 regulates b-catenin expression and signaling using bile acids deoxycholic acid (DCA), ursodeoxycholic acid acid (UCDA) derivatives that have been demonstrated by our previous studies to be able to enhance or reduce the cross-talk between Nur77 and b-catenin; to screen a chemical library of natural products for novel leads that target at the Nur77/b-catenin pathway for development of new chemotherapeutic agents.


Project Title: AACR 101st Annual Meeting 2010 GnRH promotes peritoneal adhesion and dissemination of ovarian cancer cells
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 04/2010
Completion Date: 04/2010
Abstract:
N/A


List of Research Outputs

Cheung W.T. , Leung P.C. and Wong A.S.T. , Cadherin switching and activation of p120 catenin signal ing are mediators of gonadotropin-releasing hormone to promote tumor cell migration and invasion in ovarian cancer, Oncogene . 2010, 29: 2427-2440.
Cheung W.T. , Leung P.C. and Wong A.S.T. , GnRH promotes peritoneal adhesion and dissemination of ovarian cancer cells, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5190) . 2010.
Ching W.K. , Li L. , Tsing N.K. , Tai C.W. , Ng T.W. , Wong A.S.T. and Cheng K., A Weighted Local Least Squares Imputation Method for Missing Value Estimation in Microarray Gene Expression Data, Journal of Data Mining and Bioinformatics . 2010, 4: 331-347.
Ip K.M. and Wong A.S.T. , p70 S6 kinase regulates the actin cytoskeleton in ovarian cancer cell motility by binding and cross-linking actin filaments, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5116) . 2010.
Lau M.T., Wong A.S.T. and Leung P.C., Gonadotropins induce tumor cell migration and invasion by increasing cyclooxygenases expression and prostaglandi n E2 production in human ovarian cancer cells, Endocrinology . 2010, 151: 2985-2993.
Leung K.W. and Wong A.S.T. , Pharmacology of ginsenosides: A literature review, Chinese Medicine . 2010, 5: 20.
Leung W.K., Ching A.K., Chan A.W., Poon T.C., To K.F., Wong A.S.T. and Wong N., A novel role of cdc-family gene PFTK1 in the control of liver cancer cell motility, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5297) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptosis resistance of non-adherent ovarian cancer cells thro ugh a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 1722) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptotic resistance of ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular-sig nal regulated kinase 1/2, Neoplasia . 2010, 12: 128-138.
Ting C.M., Lee Y.M., Wong C.K., Wong A.S.T. , Lung H.L. , Lung M.L. , Lo K.W., Wong R.N. and Mak N.K., 2-Methoxyestradiol induces endoreduplication through the induction of mitochondrial oxidative stress and the activation of MAPK signaling pathways, Biochem Pharmacol . 2009, 79: 825-841.
Tse Y.T. , Ko F.C.F. , Tung K.K. , Chan L.K. , Lee K.W. , Wong A.S.T. , Ng I.O.L. and Yam J.W.P. , Caveolin-1 promotes hepatocellular carcinoma tumourigenesis, migration and invasion via Met-ERK1/2 pathway, Days of Molecular Medicine 2010 Systems Biology Approaches to Cancer and Metabolic Disease, Stockholm, Sweden . 2010.
Wong A.S.T. , An experimental model of ovarian carcinoma - more than just genetics, Cell Cycle . 2010, 9: 228-229.
Wong A.S.T. , Cadherins in ovarian cancer – norm for an exception, Institute of Molecular and Cell Biology, A*STAR, Singapore, March . 2010.
Wong A.S.T. , Cadherins: unique profiles and significance in ovaria n cancer, University of Chicago, Chicago, IL, April . 2010.
Wong A.S.T. , Food and Nutritional Toxicology Lecture Series: Diet, nutrition, genes, and the life-course approach to cancer and disease prevention, Kuopio, Finland, August . 2009.
Wong A.S.T. , Hepatocyte growth factor, its receptor, and their potential as novel targets in ovarian cancer, National Singapore University, Singapore, March . 2010.
Wong A.S.T. , p70 S6 kinase: a moving new role in ovarian cancer, University of British Columbia, Child and Family Research Institute, Vancouver, BC, Canada, April . 2010.


Researcher : Wong CC

List of Research Outputs

Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptot hecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductiv e and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Campt othecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong TWL

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposi um . 2009.


Researcher : Wong WPE

List of Research Outputs

Siu E.R., Wong W.P.E. , Mruk D.D., Sze K.L. , Porto C.S. and Cheng C.Y., An Occludin-focal Adhesion Kinase Protein Complex At The Blood-testis Barrier: A Study Using The Cadmium Model, Endocrinology . 2009, 150: 3336-3344.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Wong WY

List of Research Outputs

Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhan ce uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Wong WY

List of Research Outputs

Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor respon ses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollutio n and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Wu J

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.


Researcher : Wu SS

Project Title: Polybrominated diphenyl ethers: a ubiquitous contaminant disrupting the reproductive hormones and impairing reproduction of fish?
Investigator(s): Wu SS
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2008
Abstract:
(1) Study whether, and in what way, reproductive impairment would occur in fish continuously exposed to chronic, low level of PBDEs; (2)Investigate whether PBDEs may affect production of pituitary gonadotropin hormones and their receptors; (3) Examine whether PBDEs will affect the various key genes and enzymes regulating steroidogenesis and receptors of sex hormones in fish gonads.


Project Title: Centre for Marine Environmental Research and Innovative Technology
Investigator(s): Wu SS, Lee JHW, Li XY, Li WK, Leung KMY
Department: School of Biological Sciences
Source(s) of Funding: Areas of Excellence Scheme
Start Date: 11/2009
Completion Date: 10/2012
Abstract:
n/a


List of Research Outputs

Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-se a-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wu S.S. , Fang J.K., Zheng G.J., Lam P.K.S. and Shin P.K .S., 196 Fang JKH, RSS Wu, GJ Zheng, PKS Lam and PKS Shin, 2010. Seasonality of bioaccumulation of trace organics and lysosomal integrity in green-lipped mussel Perna viridis. , Science of the Total Environment . 2010, 408: 1458-1465.
Wu S.S. , Tong E.S.P., van de Merwe J.P. and Chiu M.Y. , Effects of 1,2 dichlorobenzene on the growth, bioenergetics and reproduction of the amphipod Melita longidactyla, Chemosphere . 2010, 80: 20-27.
Wu S.S. , Hypoxia: Nothing could be worse, 6th International Conference on Marine Pollution and Ecotoxicology . 2010.
Wu S.S. , Journal of Bioindicators, 2010.
Wu S.S. , Marine and Freshwater Research . 2010.
Wu S.S. , Marine pollution bulletin . 2010.
Wu S.S. , Lam M.H.W., Li Q.L. and Jiang B.L., Rapid magnetic-mediated solid-phase extraction and pre-concentration of selected endocrine disrupting chemicals in natural waters by poly(divinylbenzene-co-methacrylic acid) coated Fe3O4 core-shell magnetite microspheres for their liquid chromatography-tandem mass spectrometry determination, Journal of Chromatography A . 2010, 1217: 1219-1226.


Researcher : Xiao J

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Xiao S

Project Title: Characterization of the pathogen-inducible promoter of ACBP3 in Arabidopsis
Investigator(s): Xiao S, Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 09/2008
Completion Date: 02/2010
Abstract:
Previous studies have revealed that recombinant ACBP3 binds [14C]arachidonyl-CoA with high affinity in vitro, in comparison to [14C]palmitoyl-CoA and [14C]oleoyl-CoA (Leung et al., 2006). By transient expression and stable transformation of Arabidopsis expressing autofluores cence-tagged fusions, ACBP3 was shown to be extracellularly-targeted via the secretory pathway (Leung et al., 2006; Xiao, 2008). It has been proposed that such extracellular localization of ACBP3 is well-positioned for its possibl e interaction with pathogens and triggering of defenses against them (Leung et al., 2006). The regulation of genes encoding plant ACBPs has not been reported. Our recent preliminary data from northern blot analysis revealed that the ACBP3 mRNA is up-regulated by pathogen infection, pathogen elicitors and defense-related phytoh ormones. It is also modulated by light/dark cycling. Hence, it would be interesting to characterize the conserved regulatory elements on the promoter of ACBP3 to provide the molecular basis for the regulated expression of ACBP3 transcription related to plant defense response. The objectives of this study are to: 1. generate a 1.5-kb fragment containing the ACBP3 promoter and to generate its deletions derivatives using Polymeras e Chain Reaction (PCR); 2. clone the PCR fragments into pGEM-T EASY vector and confirm sequences by DNA sequence analysis; 3. fuse each ACBP3 promoter fragment to β-glucuronidase (GUS) reporter gene to generate ACBP3-GUS fusions; 4. introduce the ACBP3 promoter- and deletion derivatives-GUS fusions into wild type Arabidopsis to generate stable transgenic Arabidopsis; 5. determine the regulation of ACBP3 mRNA and the effects of its deletions on transcriptional regulation in tr ansgenic plants. In Arabidopsis thaliana, besides the 10-kDa ACBP (Engeseth et al., 1996) which is designated as ACBP6 (Xiao et al., 2008), there are five larger forms (designated ACBP1 to ACBP5) ranging in size from 37.5 to 73.1 kDa (Chye, 1998; Chye et al., 2000; Leung et al., 2004, 2006). ACBP1 (Chye, 1998; Chye et al., 1999) and ACBP2 (Li and Chye, 2003) are membrane-assoc iated proteins while ACBP3 is an extracellularly-targeted protein (Leung et al., 2006). The localization of ACBP1, as investigated by western blot analysis of Arabidopsis subcellular fractions and immuno-electron microscopy using anti-ACBP1 antibodies, as well as by confocal laser scanning microscopy of autoflurescence-tagged ACBP1 transiently expressed in onion epidermal cells, localized ACBP1 to the ER and the plasma membrane (C hye, 1998; Chye et al., 1999; Li and Chye, 2003). Western blot analysis of Arabidopsis subcellular fractions and confocal microscopy of autofluorescence-tagged ACBP2 also located ACBP2 to the ER and the plasma membrane (Chye et al., 2000; Li and Chye, 2003). Extracellular localization of ACBP3 was experimentally verified by confocal laser scanning microscopy using autofluorescence -tagged ACBP3 transiently expressed in tobacco BY-2 cells and onion epidermal cells (Leung et al., 2006). The ACBP3 cleavable signal peptide was confirmed essential in extracellular secretion because removal of this peptide obliterated targeting. Northern blot analyses revealed that the ACBP3 mRNA was up-regulated by pathogen infection, pathogen elicitors and defense-related ph ytohormones, and was modulated by light/dark cycling (Xiao, 2008). Transgenic Arabidopsis overexpressing ACBP3 displayed enhanced resistance to the bacterial pathogen Pseudomonas syringae, whereas the acbp3 T-DNA insertional mutant was more susceptible to pathogen infection. The expression of PR genes in the acbp3 mutant was greatly reduced in both local and systemic leaves upon bacterial pathogen infection (Xiao, 2008). Furthermore, the ACBP3-overexpresso rs showed accelerated leaf senescence and enhanced sensitivity under constant darkness treatment (Xiao, 2008). These findings suggest that ACBP3 is likely involved in plant defense response against bacterial pathogens and in leaf senescence in Arabidopsis. To confirm gene regulation of Arabidopsis ACBP3 by pathogen and light, characterization of the conserved regulatory element s in the promoter of ACBP3 gene will be carried out. Revelations on the molecular mechanism of pathogen- and light-regulation of ACBP3 transcription expected from this study would further our understanding on the function of ACBP3 in defense and leaf senescence in Arabidopsis. References: Chye, M.L. 1998. Plant Mol. Biol. 38, 827-838. Chye, M.L., Huang, B.Q., and Zee, S.Y. 1999. Plant J. 18, 205-214. Chye, M.L., Li, H.Y., and Yung, M.H. 2000. Plant Mol. Biol. 44, 711-721. Engeseth, N.J., Pacovsky, R.S., Newman, T., and Ohlrogge, J.B. 1996. Arch. Biochem. Biophys. 331, 55-62. Leung, K.C., Li, H.Y., Mishra, G., and Chye, M.L. 2004. Plant Mol. Biol. 55, 297-309. Leung, K.C., Li, H.Y., Xiao, S., Tse, M.H., and Chye, M.L. 2006. Planta 223, 871-881. Li, H.Y., and Chye, M.L. 2003. Plant Mol. Biol. 51, 483-492. Xiao, S. 2008. PhD thesis, the University of Hong Kong. Chapter IV, 94-132. Xiao, S., Gao, W., Chen, Q.F., Ramalingam, S., and Chye, M.L. 2008. Plant J. 54, 141-151.


Project Title: 21st International Conference on Arabidopsis Research The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development
Investigator(s): Xiao S
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidy lcholine and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Xu RJ

Project Title: A study on the physiological role of transforming growth factor [beta] in postnatal ad aptation of the gastrointestinal tract in neonatal pigs
Investigator(s): Xu RJ
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To investigate the possible physiological role of TGF-[beta] in regulation of postnatal adaptation of the gastrointestinal tract in neonatal animals.


List of Research Outputs

Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prostate cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.


Researcher : Xu X

List of Research Outputs

Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Yan A

Project Title: Exploring the Regulatory Mechani sm of Escherichia coli Global Transcription Factor FNR
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 11/2008
Abstract:
Background: Molecular oxygen (O2) has a major impact on the ecosystem and life forms on earth. Bacteri a as the earliest colonizer in all life forms have developed defined regulatory systems to deal with O2 stress and facultative anaerobes are among the best known. They are able to generate ATP through both aerobic respiration when O2 is present and through fermentation when O2 is deprived. This ability of switching between aerobic and anaerobic energy generation pathway is particularly crucial for the survival and development of enterobacterial pathogens and their subsequent infection of human host, since O2 deprivation is the primary environmental stress these organisms encounter in their invasion of host gastrointestinal tract (1). In almost all of the gram negative enterobacteria, this process is primarily controlled by the global transcription factor FNR (fumarate nitrate reduction) (7). In E. coli, FNR directly senses the changes of extra-cellular O2 and alters the express ion profile of hundreds of genes (3, 4). It can both activate transcription of the genes whose products are required in anaerobic respiratory pathway and repress expression of the genes that are involved in aerobic energy generati on. The ability of FNR to function as an O2 sensor is dependent on its [4Fe-4S] cluster which is ligated to the protein through four cysteine residues at the N-terminal halve of the protein (5, 10). Under anaerobic conditions, FNR exists as a homodimer with each monomer containin g a [4Fe-4S]2+ cluster, which promotes dimerization and site-specific DNA binding and accordingly gene regulation (8). Upon a switch to aerobic conditions, the [4Fe-4S]2+ cluster is converted to a [2Fe-2S]2+ cluster by O2, resulting in the disassembly of the FNR dimer and subseque nt loss of site-specific DNA binding (5, 6). FNR is highly conserved in all enterobacteria. It belongs to the CRP/FNR superfamily of transcription factors that have a conserved helix-turn-helix motif in the C-terminal domain required for DNA binding and a diversified N-terminal domain for effector binding, such as in cAMP receptor protein (CRP), it binds cAMP. This N-terminal region confers specificity of this class of transcri ption factors in responding to extracellular signals, such as O2, CO, aromatic compounds, or oxoglutarate, etc (2, 9). While regions in E. coli FNR that are responsible for DNA binding, dimerization, as well as interaction with the RNA polymerase (RNAP) have been identified through their analogy with the corresponding regions in E. coli CRP, the function of the N-terminal region of FNR encompassed by the first 29 amino acid residu es remains unclear due to lack of a similar region in CRP. Nonetheless, this region may confer a regulatory mechanism that is unique to FNR since it is in the domain of FNR that binds Fe-S cluster and is highly conserved among FNR homologues in all enterobacteria. Objectives: This proposal aims to systematically study the functions of this unique region in FNR using the approach of alanine scanning. Owing to the fact that FNR is subject to complicated self-autoregulation (11), we will choose the pET11a as the vector in which expression of the variants will be driven by the unified T7 promoter to generate the alanine substitution library. The objectiv es of the research are: 1) Site-directed mutagenesis to generate the 3-alanine block substitution library in the N-terminal region of FNR; 2) Transformation of the mutation library to the strains that have fnr null allele and a specific promoter from an FNR activated gene being fused to lacZ (12). In vivo and in vitro assay for transcription activities of these mutants; 3) Western-blot analysis to examine the FNR protein levels in the strains that carry various of FNR mutations; 4) Further point mutation and truncation mutagenesis to dissect the roles of the amino acid residues in this region. Information from these experiments are expected to reveal the unique mechanism of FNR regulation and provide evolutionary significance for this class of transcription factor superfamily owing to the diversity of the extra-cellular signals this large class of transcription factor sensing. As a collaborator of this project, Professor Patricia J. Kiley in the Department of Biomolecular Chemistry, the University of Wisconsin – Madison, who is an expert in this area, will provide parental plasmids and strains for molecular cloning for this investigatio n as well as necessary discussion to facilitate the achievement of project objectives.


Project Title: Transcriptional regulation of multidrug resistance genes by anaerobic adaptation in Escherich ia coli
Investigator(s): Yan A, Huang J
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 07/2009
Abstract:
1) Substantiate the molecular mechanism of transcriptio nal activation of multidrug efflux transporter genes in E. coli under anaerobic conditions; 2) Examine multidrug resistance phenotype in anaerobic E. coli cells; 3) Characterize substrate capacities and mechanisms of selective drug exporters.


Project Title: The 2009 Molecular Genetics of Bacteria and Phages Meeting The N- and C- terminal regions of E. coli global transcription factor FNR participate in regulation of FNR protein levels
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Explore and molecular engineering of FNR family proteins that lead to altered sensitivity to oxygen
Investigator(s): Yan A, Sun H
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Metalloproteins are ubiquitous in nature, accounting for 30% of all proteins in biological kingdoms. They provide unique structural framework for protein folding and serve as excellent electron carriers in oxido-red uction, thus are widely distributed in many cellular and physiological processes in nature, such as the life-sustaining process of respiration, nitrogen fixation, various metabolic pathways and photosynthesis, etc (2, 3). While their involvement in the redox catalyses has been well documented, participation of metal centers in transcriptional regulation signifies a renewed function of this class of ancient proteins that merely becomes evident since last decade (5, 6). The global transcription factor FNR that primarily controls the transition from aerobic to anaerobic lifestyle in most enteric bacteria is a paradigm of these regulatory metal proteins (6, 7). It senses O2 deprivation and promotes anaerobic metabolism by regulatin g the expression of hundreds of genes in an organism’s genome. In E. coli and many other enteric bacteria, the mechanism for FNR to sense and respond to O2 limitation is dependent on an [4Fe-4S]2+ cluster that is integrated into FNR through four essential cysteine residues. Under anaerobic conditions, FNR exists as a holo-form with a [4Fe-4S]2+ cluster present at its N-terminus. The binding of the [4Fe-4S]2+ cluster promotes dimer ization of FNR, and subsequently enables site-specific DNA binding and transcription regulation (8, 9). Upon switch to aerobic conditions, O2 rapidly reacts with the [4Fe-4S]2+ cluster and converts it to a [2Fe-2S]2+ cluster. The [2Fe-2S]2+ form of protein (referred as 2Fe-FNR) is unable to dimerize, thus the protein loses its capability of site-specific binding of DNA and transcription regulation (4, 12). The 2Fe-FNR is further converted by the superoxide species, presumably a by-product of aerobic metabolism, to the cluster-less apo-FNR, a form that exists in aerobically grown E. coli (13). FNR homologues broadly exist in the species of γ-proteobacteria including some human pathogens, such as Salmonella typhimurium, Yersinia pestis, Vibrio cholerae, Pseudomonas aeruginosa, etc (7). In addition to anaerobic respiration, they mediate a diversity of cellular and physiological activities in these organisms, including denitrification, anoxygenic photosynthesis, nitrogen fixation and haemolysis. All of these FNR homologues contain the conserved cysteine residues that are required for cluster binding, sugg esting a similar Fe-S cluster dependent mechanism in these proteins (7). However, the natural and symbiotic habitats of these organisms vary and the degree of O2 deprivation these organisms can survive is not the same. How the same type of O2 sensor ([4Fe-4S]2+ cluster) respond to different ranges of O2 levels is essentially unkno wn. Since the structure and oxidation state of the [4Fe-4S]2+ cluster in these FNR homologues is identical, we hypothesize that the local protein environments surrounding the cluster may determine the stability of their [4Fe-4S]2+ cluster to O2, thus specifies the range of O2 level a microorganism can live. Two other facts support this hypothesis: 1) although a vast number of biologically important proteins contain Fe-S clust ers and employ the clusters for catalysis and function, there are only four basic types of Fe-S clusters. The specific roles of the Fe-S clusters in these different metalloproteins are at least partially attributed to the local environments formed by peptide backbones of the proteins; 2) previous studies have identified an N-terminal point mutation L28H FNR that is stable to O2 and is active in transcription regulation under aerobic conditions (1), suggesting amino acid residues in this, and probably other regions may contribute to the cluster stability. In this proposal, we aim to identify amino acid residues that control the acquisition and stability of Fe-S clusters in FNR-like proteins and uncover how these elements affect the capacity of FNR homologues to sense O2, as well as how this effect contributes to specify the ecological and physiological niches these microorganisms habitat. The specific aims are: 1. Identify regions in E. coli FNR that contribute to the acquisition and stability of Fe-S clusters and screen for O2 stable variants. 2. Purify and in vitro characterization of selective va riants. 3. Incorporate the engineered constructs into E. coli genome and test the growth of engineered strains under various ranges of O2 concentrations.


Project Title: HKU Overseas Fellowship Awards 2010-11
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: HKU Overseas Fellowship Awards
Start Date: 06/2010
Abstract:
To visit the Great Lakes Bioenergy Research Centre and Department of Bacteriology at the University of Wisconsin-Madison, USA to learn and receive training on several recently developed genome-wide approaches in the study of microbial gene expression and conduct collaborative studies on the kinetics of an FNR mutant.


List of Research Outputs

Yan A. , HKU Overseas Fellowship Award 2010, The University of Hong Kong . 2010.
Yan A. and Kiley P... .J..., Techniques to isolate O2-sensitive proteins: [4Fe-4S]-FNR as an example, In: Richard R. Burgess and Murray P. Deutscher, Guide to Protein Purification, 2nd Edition . Elsevier publisher, 2009, 463: 787-805.
Yan A. and Pan Q. , The N- and C- terminal regions of E. coli global tran scription factor FNR participate in regulation of FNR protein levels, Molecular Genetics of Bacteria and Phages Meeting 2009, August 4-9, Madison, WI, USA . 2009.


Researcher : Yan HNH

List of Research Outputs

Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Yang Y

List of Research Outputs

Yang Y. and Dudgeon D. , Dietary variation and food selection by an algivorous loach (Pseudogastromyzon myersi: Balitoridae) in Hong Kong streams., Marine and Freshwater Research . 2010, 61: 49-56.
Yang Y. and Dudgeon D. , Response of grazing impacts of an algivorous fish (Pseudogastromy zon myersi: Balitoridae) to seasonal disturbance in Hong Kong streams. , Freshwater Biology . 2010, 55: 411-423.
Yang Y. and Dudgeon D. , Spatial and seasonal variations in benthic algal assemblages in streams in monsoonal Hong Kong., Hydrobiologia . 2009, 632: 189-200.


Researcher : Yau CST

List of Research Outputs

Sin Y.W., Chu K.H. and Yau C.S.T. , Isolation and characterization of highly polymorphic microsatellites in the mitre squid, Uroteuthis (Photololig o) chinensis, Molecular Ecology Resources . Blackwell Publishing Ltd, 2009, 9: 1460-1559.
Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.


Researcher : Yeung SL

List of Research Outputs

Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Yeung WY

List of Research Outputs

Yeung W.Y. and Leung K.M.Y. , Effects of tissue types, animal size, nutritional status and metal exposure on the RNA/DNA ratio in various tissues to the green-lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Yeung W.Y. and Leung K.M.Y. , Spatio-temporal variations in metal accumulation, RNA /DNA ratio, energy reserves and condition index in transplanted green-lipped mussels Perna viridis in sub-tropical Hong Kong waters, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Yip CW

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductiv e and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Yip WK

Project Title: Functional characterization and subcellular localization of three ethylene receptors in rice
Investigator(s): Yip WK, Yau CP
Department: Botany
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2005
Abstract:
Ethylene is an important plant hormone which regulates a range of developmental and physiological process in plants. In the past decades, exceptional progress has been made on understanding the molecular mechanism controlling the ethylene signalling pathway which was shown to require membrane-associated ethylene receptors to function. In Arabidopsis, there are altogether five ethylene receptors which negatively regulate ethylene responses. However, little is known about the involvement of receptor genes in the ethylene perception of monocotyledonous plants such as rice. Recently, we have successfully isolated five putative ethylene receptor genes from rice and showed that their expression levels were regulated developmentally, and by various external stimuli including ethylene. Here we propose to functionally characterize three rice ethylene receptor genes, OS-ERS1, OS-ERS2 and OS-ETR2 in planta. Moreover recent studies on the subcellular localization of two ethylene receptors, At-ETR1 and NtHK1 (an ethylene receptor ortholog in tobacco) revealed that they were localized to endoplasmic reticulum and plasma membrane respectively. To understand more in detail how these three rice ethylene receptors function in cellular level, we propose to investigate their corresponding subcellular localization by fusin g with fluorescent protein.


Project Title: Characterization of a cyanide detoxification gene encoding L-3-cyanoalanine synthase (CAS), and determine its roles among the cysteine synthase (CS)/CAS family in the rice genome
Investigator(s): Yip WK
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
(1) Study of OS-CAS transcription by promoter analyses; (2) heterologous expression of OS-CAS in bacteria dnd yeast to test its catalytic activity; and unravel the structure and function relationships between CS and CAS by site directed mutagenesis studies; (3) subcellular localization of OS-CAS by tagging it with the yellow fluorescent protein (YFP); (4) the roles of OS-CAS and CS on cyanide detoxification and cysteine synthesis in rice; to investigate whether quincorac or 2,4 D resistant in rice is conferred by OS-CAS.


Project Title: The study of plant hormone interactions on growth, development and physiological responses using ACC synthase gene suppression mutants in tomatoes.
Investigator(s): Yip WK
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
(1) Elucidation the interactions among ethylene, abscisic acid, and IAA on stomatal aperture and transpi ration. (2) Elucidation the interactions among ethylene, abscisic acid, and IAA on seedling growth. (3) Study on the possible hormonal interactions between ethylene and ABA in seed development in tomato fruits. (4) Gene discovery on important plant processes by employing the RNA micro-array analyses.


Project Title: Molecular studies on two components OASS and SAT of rice cysteine synthase complex and cysteine regeneration during ethylene biosynthesis
Investigator(s): Yip WK
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To have a basic understanding of the gene expression profiles of the OASS/CAS gene family members during seedling growth in light and in dark, and also under the ethylene/auxins treatments; (2) To find out the subcellular localization of individual OASS/CAS membe rs; (3) To verify the functions of OASS/CAS, and SATs encoded by these two gene families by complementation expression in bacteria or yeast mutants; (4) To elucidate the CS complex formation of gene products encoded by these two gene families and find out whether hetero-subunits formation would be possible; (5) To determine whethe r cysteine synthesis would be possible in rice mitochondria or cysteine has to be imported from cytosol during active ethylene biosynthesis.




Researcher : Yu M

List of Research Outputs

Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.
Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Yu X

List of Research Outputs

Yu X. and Gu J.D. , Effect of temperature on removal of iron cyanides from solution by maize plants, Environmental Science and Pollution Research . Berlin / Heidelberg, Springer, 2010, 17: 106-114.


Researcher : Zeng F

List of Research Outputs

Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origin s Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Zeng X

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vita mins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-85 . 2010.


Researcher : Zeng X

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vi tamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, Uni ted States, March 21-25, AGFD-85 . 2010.


Researcher : Zhang Y

List of Research Outputs

Zhang Y. and Dudgeon D. , Impacts of deforestation and hydrological change on river ecosystems in Southeast Asia. , In: L. Lebel, A. Snidvongs, C.-T. A. Chen & R. Daniel, Critical States: Environmental Challenges to Development in Monsoonal Southeast Asia . Petaling Jaya, Malaysia, , Strategic Information and Research Development Centre, 2009, 268-280.


Researcher : Zheng S

List of Research Outputs

Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Zheng Z

List of Research Outputs

Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C. G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-none nal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonen al, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induce d cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zheng Z

List of Research Outputs

Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zhou L

List of Research Outputs

Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cyathostemma , Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitat ion of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodorum, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Zhu F

List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthoc yanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prostate cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/gluco se model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Zhu F

List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocya nidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prosta te cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Zhu Q

List of Research Outputs

Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zhu Q

List of Research Outputs

Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, Un ited States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-n onenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-no nenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-ind uced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zurcher NA

List of Research Outputs

Leung M.C.C., Hui J.C.T., Zurcher N.A. , Yuan D.X. and Leung K.M.Y. , Trace metals and methyl mercury in sharks' fins: potential health risk for consumers, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


-- End of Listing -- School of Biological Sciences

SCHOOL OF BIOLOGICAL SCIENCES



Researcher : Arrigoni JR JE

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predat or on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.


Researcher : Attanayake MAS.A.

List of Research Outputs

Attanayake M.A.S...A... , Ratnayake R.M.C. and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Attanayake M.A.S...A... and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpi folia (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Bao J

List of Research Outputs

Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.


Researcher : Bao WW

List of Research Outputs

Bao W.W. , Qiu J.W., Lam M.H.W. and Leung K.M.Y. , Acute toxicities of five commonly used antifouling booster biocides to selected tropical/subtropical marin e species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Acute toxicities of zince pyrithione alone and in combination with copper to marine autotrophic species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City Universi ty of Hong Kong, Hong Kong . 2010.
Bao W.W. , Leung K.M.Y. and Lui G.C.S. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Leung K.M.Y. and Bao W.W. , A unifying model for predicting temperature-dependent toxicity of pollutants: an insight to the interacting effect of climate change and chemical pollution, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Brooks JD

List of Research Outputs

Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.


Researcher : Bugler-Lacap DC

List of Research Outputs

Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.
Wong K.Y. , Lau C.Y. , Bugler-Lacap D.C. , Aitchison J.C. , Cowan D.A. and Pointing S.B. , Endolithic microbial colonization of limestone in a high-altitude arid environment, Microbial Ecology . Springer Science, 2009, 59: 689-699.


Researcher : Cai Y

Project Title: An investigation on inhibitory effect and primary mechanism of natural phenolic antioxidants against acrylamide formation in fried and baked carbohydrate-ri ch foods
Investigator(s): Cai Y, Corke H
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2008
Abstract:
(1) To develop a new effective and safe approach to significantly inhibit or reduce acrylamide levels in fried and baked carbohydrate-rich foods through addition of natural phenolic antioxidants; (2) To eval uate inhibitory effect of different natural phenolic antioxidants from common dietary plants against acrylamide formation in fried and baked carbohydrate-rich foods; (3) To search for strong natural inhibitors to effectively reduce acrylamide levels in fried and baked carbohydrate -rich foods; (4) To investigate primary mechanism of action of the strong natural inhibitors in reducing acrylamide levels during heating of an asparagine-glucose model system; (5) To provide a work basis for further study. We will continue tests in more model food systems and in more practical application in fried and baked carbo hydrate-rich foods.


Project Title: 14th World Congress of Food Scie nce and Technology Effects of phytochemicals on reduction of acrylamide in an asparagine/glucose model system
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2008
Abstract:
N/A


Project Title: Screening and evaluation of novel acrylamide-reduced ingredients for development of health y bakery products
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2009
Completion Date: 06/2010
Abstract:
Formation and reduction of the potentially toxic acrylamide during baking or frying of carbohydrate-rich foods has been an important worldwide topic of food safety concern. The Food and Agriculture Organization (FAO) and World Health Organization (WHO) of the United Nations have concerned the risk of acrylamide in foods since 2002. They concluded in 2005 that acrylamide in foods was a potential health hazard and its most important toxic effect may be the cancer risk (Taeymans et al., 2004; INFOSAN, 2005; Zhang and Zhang, 2007). The Joint FAO/WHO Food Standards Programme Codex Committee organized the first session about ‘Proposed Draft Code of Practice for the Reduction of Acrylamide in Foods’ in April 2007 in Beijing. This draft code for limits for acrylamide focused on potato and cereal products. The Food and Environmental Hygiene Department (FEHD) of Hong Kong SAR assessed the levels of acrylamide ( <10-2600 ug/kg) in fried and baked carbohydrate-rich foods (e.g. potato crisps, chips, cookies/biscuits, breads, and cereal snacks) collected in local markets in 2003 and 2006 (Leung et al., 2003; CFS and CC, 2006). The results showed that some foods (e.g., potato crisps/ch ips, biscuit-related products, wheat/rye flour-based crisps/breads) contained significant amounts of acrylamide (200-1700 ug/kg). To minimize the risk of acrylamide, the Center for Food Safety (CFS) and the Consumer Council (CC) of Hong Kong has appealed to institutions and food industries to research and develop methods and techniques to reduce acrylamide in fried and baked carbohydrate-rich foods (CFS and CC, 2006). Since fried potato products could form higher levels of acrylamide than bakery products (e.g. breads and biscuits), previous acrylamide-reduced studies focused on potato products (mainly potato crisps and French fries), but the fewer relevant studies on bakery products were conducted (Zhang and Zhang, 2007; Friedman and Levin, 2008). Investigation of impact factors on the formation and reduction of acrylamide in fried and baked carbohydrate-rich foods included processing conditions (pH, heating time and temperature), concentration of acrylamide precursors (mainly asparagine and glucose), and chemical/food additives, etc. Some progresses on reduction of acrylam ide have been achieved. However, most of the current methods and techniques have not been used in food industry (especially production of bakery products) and some chemical additive pretreatments could generate new hazards in the final food products. Although bakery products (mainly breads and biscuits/cookies) contain lower levels of acrylamide (~100-720 ug/kg) than fried potato products (~250-1000 ug/kg) (CFS and CC, 2006), the acrylamide in breads and biscuits is still a potential health risk because consumers daily eat these conventional foods and can be frequently exposed to the acrylamide. Furthermore, fewer acrylamide-reduced studies have been currently conducted on bakery products than on potato crisps and French fries. Thus, it is necessary not only to pay attention to the risk of acrylamide in bakery products but also to find new materials an d safe approaches to reduce their acrylamide levels for minimizing the risk of acrylamide to consumers. The technological challenge of this project is how to significantly reduce acrylamide in bakery products while avoiding significant changes in the sensory quality of target products caused by addition of acrylamide-reduced in gredients. The objectives of this project are: (1) To select various kinds of functional materials (e.g. oligosaccharides, non-starch polysaccharides, inulin, resistant starch, various grain fibers, soymilk/protein hydrolysates, and phytochemicals) for determining their acrylamide-reduced levels in an asparagine/glucose model system in order to screen novel acrylamide-reduced ingredients; (2) To evaluate the acrylamide-reduced effectiveness of the primarily selected ingredients in bakery products (mainly breads and biscuits) for screening the better ones for further experiment; (3) To investigate the synergic effects of the better acrylamide-reduced ingredients mixed in breads and biscuits; (4) To optimize the levels/formulations of the better functional ingredients and the processing procedures of the healthy biscuits and breads with the reduced 50-80% acrylamide and to set up the standard processing protocols of the relevant food products; (5) To conduct sensory evaluation (e.g., texture, crispness, crust, color, flavor/taste, overall acceptability, etc.) of the final products with low level of acrylamide to meet consumer acceptability. The ultimate purpose of this project is that end-users of our studied acrylamide-reduced ingredients can use these for further development and production of healthy bakery products to minimize the risk of acrylamide to consumers in the Greater China region including Hong Kong and in the world. References cited are listed in the attached file.


Project Title: 6th International Congress on Pi gments in Food Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system
Investigator(s): Cai Y
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Cai Y. , Ke J.X. and Corke H. , MALDI-QIT-TOF MS determination of proanthocyanidins in crude extracts of selected dietary plants and medicin al herbs (Abstract), Global Chinese Health (Functional) Food Symposium 2009 (Hong Kong) . 2009.
Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prosta te cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Xiong G.Q., Cheng W., Ye L.X., Du X., Zhou M., Lin R.T., Geng S.G., Chen M.G., Corke H. and Cai Y. , Effects of konjac glucomannan on physicochemical properties of myofibrillar protein and surimi gels from grass carp ( Ctenopharyngodon idella ), Food Chemistry . 2009, 116 (2): 413-418.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Chak STC

List of Research Outputs

Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Thiel M., Chak S.T.C. and Dumont C. , Mating behavior of the dancing shrimp Rhynchocinetes brucei (Decapoda: Caridea), Journal of Crustacean Biology . 2010, 33: 580-588.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Chan KH

List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.


Researcher : Chan KK

List of Research Outputs

Poon D., Chan K.K. and Williams G.A. , Spatial and temporal variation in the diets of the crabs Metopograpsus frontalis (Grapsidae) and Perisesarma bidens (Sesarmidae): implications for mangrove food webs., Hydrobiologia . 2010, 638: 29-40.


Researcher : Chan KY

List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Chan LL

Project Title: Algal Toxins: Development of Analytical Bioassay Detection Methods and Assessment of Environmental Transfer in Marine Food Webs
Investigator(s): Chan LL
Department: School of Biological Sciences
Source(s) of Funding: Collaborative Research Fund (CRF) - Group Research Project
Start Date: 06/2009
Completion Date: 10/2010
Abstract:
1) Collect toxic and non-toxic fish and shellfish species from Maine and the west coast of the USA, Shenzhen, China, and the Republic of Kiribati in conjunction with collaborating institutions; 2) Measure toxins responsible for paralytic shellfish poisoning (PSP) in the collected shellfish species using established high-performance liquid chromatography-mass spectrometry (HPLC-MS) and bioassay methods; 3) Develop and validate an instrumental method and bioassays for measuring toxins involved in ciguatera fish poisoning (CFP), and develop commercial standards; 4) Use these optimized methods to develop a rapid testing protocol for fish and shellfish for human health protection; 5) Compare gene and protein expression profiles between toxic and non-toxic shellfish/fish species, and in shellfish/fish that retain toxins for long periods, using genomic and proteomic techniques in order to determine why some shellfish or fish species are toxic while others are not; and 66) Use molecular and stable isotope and fatty acid methods to determine the sources, dynamics and fluxes of PSP and CFP toxins in marine food webs/ecosystems.




Researcher : Chan MN

List of Research Outputs

Xi Y. , Huang B. , Djurisic A. , Chan M.N. , Leung F.C.C. , Chan W.K. and Au D.T.W., Electrodeposition for antibacterial nickel-oxide-based coatings, Thin Solid Films . Amsterdam, Elsevier B.V., 2009, 517: 6527-6530.


Researcher : Chao J

List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatechin-3 -gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methyl ated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Chao J

List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatec hin-3-gallate (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Chen Q

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidylcholin e and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Chen SF

Project Title: Metabolic engineering for enhanced astaxanthin biosynthesis in Chlorella zofingiensis (Chlorophyta)
Investigator(s): Chen SF, Huang J
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
To establish a chlorella transformation system; to introduce a heterologous carotenoid hydroxylase gene into C. zofingiensis ; to study the regulation of astaxanthin biosynthesis in the engineered host; to maximize the production of astaxanthin in the genetically manipulated C. zofingiensis .


Project Title: Genetic enineering of a green alga l phytoene desaturase for herbicide resistance and its use as a selectable marker for nuclear transformation
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2008
Completion Date: 09/2009
Abstract:
The eukaryotic green algae are photoautotrophs, requiring only sunlight, carbon dioxide, water and basic nutrients for maximal growth. Because they potentially provide all the benefits of higher plants with large-scale microbiol production approaches, green microalgae may be an attractive alternative to the other microbial systems currently in use. Microalgae have already served as a major natural source of valuable molecules including carotenoids, long-chain polyunsaturated fatty acids and phycocolloids. In recent years, there has been a surge of interest in microalgal metabolites as a source of novel molecules. However, it is difficult to produce stable transformants of most microalgae due to the lack of proper selectable markers and promoters to drive heterologous gene expression. Chlamydomonas reinhardtii is a widly used model system for basic biological and ecological studies, especially those that cannot be investigated in bacteria and yeast (Rochaix, 1995). The recently developed techniques for nuclear and organelle transformation (Boynton et al., 1988; 1993; Kindle, 1990) have greatly expanded the use of this alga as a model system. However, it is difficult for C. reinhardtii to express heterologous genes. Therefor e, the development of dominant selectable markers is still severely hampered. Efficient transformation systems for algae commonly rely on homologous genes that complement auxotrophic mutations which are unavailable for most algae. For the expression of heterologous genes, homol ogous promotor and 3' regions providing a cognate polyadenylation signal are highly required. Up to date, only a few selectable markers are available for a few model organisms, such as the green alga C. reinhardtii, the diatom Pha eodactylum tricornutum, etc. Compared with higher plants, the transformation of algae is still in its infancy because no unviversal tools (e.g. expression cassette and selectable markers) as those used in higher plants (e.g. 35S promoter and Agrobacterium transformation system) are available for algae. Carotenoids are essential components of the photosynthetic apparatus. They participate in light harvesting and protect the chloroplasts from the harmful effect of single oxygen formed during photosynthe sis (Windhovel et al., 1994). The enzyme phytoene desaturase (PDS) is the main target for herbicides that prevent the formation of zeta-carotene, resulting in the degradation of chlorophyll and the destruction of chloroplast membr anes. Mutations (some amino acid substitutions) of the cyanobacterium Synechococcus PDS, the aquatic weed Hydrilla verticillata PDS resulted in herbicede-resistant PDS enzymes (Chamovitz et al., 1991; Michel et al., 2004), and have conferred herbicide resistance when expressed in plants (Wagner et al., 2002; Arias et al., 2006). We hypothesize that similar amino acid substitutions in PDS of eukaryotic algae could also resist to herbicide. Thus, the PDS from microalgae can be modified as dominant selectable markers used for genetic engineering of biotechnologically important microalgae for which no successful genetic manipulation is available up to date. The purpose of the proposed project is to develope a dominant selectable marker for nuclear transformantion of microalgae by modifying a homologous PDS gene that will confer herb icide resistance when expressed in algae. To achieve this project aim, the gene coding for the carotenoid biosynthetic enzyme PDS from C. reinhardtii will be isolated. This gene will be mutated and functionally analysed in recombi nant E. coli and in vitro assay for herbicide resistance. Herbicide-resistant PDSs will be inserted into C. reinhardtii expressing cassete (Stevens et al. 1996; Cerutti et al., 1997; Schroda et al., 2000) and introduced into the algal cells using the method introduced by Kindle (1990). Herbicide resistance and pigment profiles of transformants will be assessed. References 1. Arias , R.S., Dayan, F.E., Michel, A., Howll, J., and Scheffler B.E. (2006) Characterization of a higher plant herbicide-resistan t phytoene desaturase and its use as a selectable marker. Plant Biotechnology Journal 4, 263-273. 2. Boynton, J.E., Gillham, N.W., Harris, E.H., Hosler J.P. Johnso, A.M., Jones, A.R., Randolph-Anderson, B.L., Robertson, D. Klein., T.M., Shark, K.B., and Sanford, J.C. (1988) Chloroplast transformation in Chlamydomonas with high velocity microprojectiles. Science 240, 1534-1538. 3. Cerutti, H., Johnson, A.M., Gillham, N.W. and Boynton, J.E. (1997) A eubacterial gene conferring spectinomycin resistance on Chlamydomonas reinhardtii: integration into the nuclear genome and gene expression. Genetics, 145, 97-110. 4. Chamovitz, D., G. Sandmann, and J. Hirschberg. (1993) Molecular and biochemical characterizat ion of herbicide-resistant mutants of cyanobacteria reveals that phytoene desaturation is a rate-limiting stepin carotenoid biosynthesis. J. Biol. Chem. 268, 17348-17353. 5. Kindle, K.L. (1990) High-fregquency nuclear transformat ion of Chlamydomonas reinhardtii. Proc. Natl. Acad. Sci. USA 87, 1228-1232. 6. Rochaix, J.-D. (1995) Chlamydomonas reinhardtii as the photosynthetic yeast. Annu. Rev. Genet. 29, 209-230. 7. Schroda, M., Blocker, D., and Beck, C.F. (2000) The HSP70A promoter as a tool for the improved expression of transgenes in Chlamydomonas. Plant J. 21, 121-131. 8. Stevens, D.R., Rochaix, J.-D. and Purton, S. (1996) The bacterial phleomycin resistance gene ble as a dominant selectable marker in Chlamydomonas. Mol. Gen. Genet. 251, 23-30. 9. Wagner T., Windhovel, U., and Romer. S. (2002) Bansformation of tobacco with a mutated cyanobacterial phytoene desaturase confers resistance to bleeching herbicides. Z Naturforsch 57, 671-679. 10. Windhovel, U., Geiges, B., Sandmann, G., and Boger, P. (1994) Expression of Erwina Uredovora phytoene desaturase in Synechococcus PCC 7942 leading to resistance against bleaching herbicides. Plant Physiol. 102, 119-125.


Project Title: Directed evolution of carotenoid ketolase and hydroxylase for investigating the molecular basis of enzyme function and astaxanthin biosynthesis
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2008
Abstract:
(1) to investigate the BKT activity toward zeaxanthin for astaxanthin production; (2) to investigate the CHYb activity toward beta-carotene for zeaxanthin production ; (3) to study the molecular basis of the enzymes for activity and substrate specificity; (4) to elucidate the evolution of astaxanthin biosynthesis.


Project Title: Chloroplast genome engineering of Chlamydomonas reinhardtii for metabolic pathway study
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Abstract:
Astaxanthin is a red ketocarotenoid that occurs only in a limited number of bacteria, fungi, and in certain unicellular algae (Boussiba, 2000). This red pigment has been widely used as a feed supplement in aquaculture and poultry industries (Johnson and Schroeder 1995). In addition, due to its high antioxidant activity, astaxanthin has also been used commercially as nutraceuticals and for cosmetic and pharmaceutical purposes (Lorenz and Cysewski 2000, Guerin et al. 2003). The unicellular green microalga Haematococcus pluvialis reveals the highest astaxanthin accumulation (up to 4% of dry biom ass) (Boussiba et al., 1992). H. pluvialis has served as a natural source of astaxanthin. The slow growth rate and lack of a genetic transformation system of this alga, however, limit its application. In contrast, other astaxanthin-producing microorganisms have much lower cellular astaxanthin content. With very few exceptions, higher plants normally do not synthesize astaxanthin. In recent years, the carotenoid biosynthetic pathway in some plants has been extended to astaxanthin by nuclear transformation of a heterologous β-carotene ketolase (bkt) gene. However, in all cases, only trace amounts of astaxanthin were synthesized in the transgenic plants. Knowledge of ketocarotenoid biosynthesis is very limited, which greatly hinders the exploitation and application of astaxanthin-producing organisms and transgenic plants as natural sources of ketocarotenoids on an industrial scale. Recently, biosynthesis of astaxanthin in tobacco leaves was achieved by plastid transformation, which highlights the utility of plastid transformation as an excellent tool to drastically alter carotenoid compositions and contents in algae and crop plants. (Husunuma et al., 2008). The unicellular geen alga Chlamydomonas reinhardtii is an important model organism for studies of photosynthesis and pigment biosynthesis (Harris 1989). No astaxanthin has been reported to occur in C. reinhardtii although its genome contains an open reading frame with strong similarity to BKT enzymes from the green algae H. pluvialis and Chlorella zofingiensis (Grossman et al. 2004, Huang et al. 2006a, b). We have recently characterized the putative Chlamydomonas BKT and found it to possess ketolase activity. RT-PCR detection revealed that the expression of the bkt gene was too low to trigger the cell to produce astaxanthin. We therefore hypothesized that the low expression of the bkt gene is the limiting factor for C. reinhardtii to synthesize ketocarotenoids. To prove the hypothesis, we introduced a Haematococcus bkt into C. reinhardtii by nuclear transformation. However the genetic modified cells failed to produce significant amounts of ketocaroteno ids even though all the elements required for optimal transcription and translation (promoter, intron and other regulatory regions) had been included in the chimeric gene construc tion. RT-PCR detection revealed very low expression of the transgene, possibly resulting from the so-called gene silencing. Very recently, robust expression of heterologous genes has been achieved in Chlamydomonas chloroplast by plastid transformation (Mayfield et al., 2007). Transgene expression from the chloroplast genome offers several advantages over nuclear transformation, including high-level accumulation of foreign proteins, transgene stacking in operons and a lack of epigenetic interference with the stability of transgene expression (Bock 2007). Thus we propose to solve the problem of low expressio n of transgenes in C. reinhardtii by chloroplast genome engineering. The purpose of this proposed research is to develop a model system for the study of astaxanthin biosynthesis in green algae. The unicellular green alga C. reinhardtii, to which its chloroplast DNA can be easily transformed, will serve as a target organism and genetically be engineered by introducing a novel copy of bkt gene into its chloroplast via plastid tra nsformation. It is expected that the modified cells will produce and accumulate astaxanthin in the chloroplast which takes up about half of the cell volume. The established system will help to reveal the regulation of astaxanthin biosynthesis in the green alga H. pluvialis, the organism with the richest astaxanthin content in nature. References Bock R. (2007) Plastid biotechnology: prospects for herbic ide and insect resistance, metabolic engineering and molecular farming. Curr. Opin. Biotechn. 18: 100-106. Boussiba (2000) Carotenogenesis in the green alga Haematococcus pluvialis: cellular physiology and stress response. Physiol. Plantarum. 108:111-117. Boussiba, S., Fan, L. & Vonshak, A. 1992. Enhancement and determination of astaxanthin accumulation in green alga Haematococc us pluvialis. Method Enzymol. 213: 386-391. Grossman, A. R., Lohr, M. & Im, C. S. 2004. Chlamydomonas reinhardtii in the landscape of pigments. Annu. Rev. Genet. 38:119-173. Guerin, M., Huntley, M. E., & Olaizola, M. 2003. Haematococcus astaxanthin: applications for human health and nutrition. Trends Biotechnol. 21:210-216. Harris, E. H. The Chlamydomonas Sourcebook, Academic Press, San Diego, 1989 Huang, J.C., Wang, Y., Sandmann, G. & Chen, F. 2006a. Isolation and characterization of a carotenoid oxygenase gene from Chlorella zofingiensis (Chlorophyt a). Appl. Microbiol. Biotechnol. 71:473-9. Huang, J.C., Chen, F. & Sandmann, G. 2006b. Stress-related differential expression of multiple beta-carotene ketolase genes in the unicellular green alga Haematococcus pluvialis. J. Biotechnol. 122:176-85. Johnson, E. A. & Schroeder, W. A. 1995. Microbial carotenoids. Adv. Biochem. Eng . Biotechnol. 53:119-178. Lorenz, R. T. & Cysewski, G. R. 2000. Commercial potential for Haematococcus microalgae as a natural source of astaxanthin. Trends Biotechnol. 18:160-167. Mayfield S.P., Manuell A.L, Chen S. et al. (2007) Chlamydomonas reinhardtii chloroplasts as protein factories. Curr. Opin. Biotechn. 18:126-133.


Project Title: Assess the potential of the green microalgae Chlorella species as biodiesel feedstocks
Investigator(s): Chen SF, Huang J
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Petroleum fuels are recognized as unsustainable due to their depleting supplies and contribution to global warming (Chisti, 2008). Renewable biofuels are promising alternatives to petroleum fuels, among which biodiesel has attracted the most attention in recent years (Knothe et al., 1997, 2006; Fukuda et al., 2001; Gerpen, 2005; Meher et al., 2006; Hu et al., 2008). Biodiesel is a diesel-equivalent fuel derived from biological feedstocks and is chemically referred to as a fatty acid methyl ester (FAME). In comparison with traditional fuels, biodiesel is carbon neutral, contributes less emission of gaseous pollutants and so is environmentally beneficial (Ma and Hanna, 1999 ). Current biodiesel is mainly derived from vegetable oils, animal fats and waste cooking oils (Knothe et al., 1997; Lang et al., 2001; Al-Widyan et al., 2002; Zhang et al., 2003; Demirbas, 2005). However, such sources of biodiesel cannot meet the existing need for transport fuels as immense cultivation lands have to be taken up for oil crops (Chisti, 2007). The relatively high cost of using vegetable oil as feedstock also restricts the commercialization of biodiesel (Lang et al., 2001). Microalgae are sunlight-driven cell factories that convert carbon dioxide to potential biofuels, foods, feeds and high-value bioactives (Spol aore et al., 2006). Microalgae have being considered as feedstocks for biodiesel production because of their rapid growth and high contents of lipids (Chisti, 2007; Hu et al., 2008). Unlike oil crops, microalgae can be easily cultured in outdoor ponds or bioreactors (Chen, 1996; Del Campo et al., 2007; Pruvost et al., 2009), making it be a more competent alternative to oil crops in biomass production. When consider a microalgal feasibility for mass biodiesel production, two key factors, namely cell biomass and lipid content are essential for the initial assessment. Thus microalgae with fast-growth and high lipid productivity are desirable for biodiesel exploitation. The green microalgae Chlorella species consist of about 10 species, most of which can grow fast photoautotrophically, mixotrophically and heterotrophically (Chen, 1997; Shi et al., 2002; Ip et al., 2004; Miao and Wu, 2004). High contents of lipids have been reported in some of the species, such as C. vulgaris and C. protothecoides (Miao and Wu, 2004; Liu et al., 2008; Hsieh and Wu, 2009). Compared with photoautotrophic culture, heterotrophic culture can obtain much higher biomass as demonstrated by C. zofingiensis that at least 5-fold biomass was obtained by heterotrophically culturing the alga using glucose as sole carbon and energy source (Sun et al., 2008). The heterotrophic ability of Chlorella species also eliminates light requirement that is essential for photoautotrophic microalgae and therefore reduces the cost in the production process (Borowitzka, 1999). The purpose of this proposed project is to assess several Chlorella species for their potential as novel sources of biodiesel by the investigation of their heterotrophic growth and fatty acid productivity with various organic carbon sources and different stress conditions. References Al-Widyan, M.I., Al-Shyoukh, A.O., 2002. Experimental evaluation of the transesterification of waste palm oil into biodiesel. Bioresour. Technol. 85, 253-256. Borowitzka, M.A., 1999. Commercial production of microalgae: ponds, tanks, tubes and fermenters. J. Biotechnol. 70, 313-321. Chen, F., 1996. High cell density culture of microalgae in heterotrophic growth. Trends Biotechnol. 14, 421-426. Chisti, Y., 2008. Biodiesel from microalgae beats bioethanol. Trends Biotechnol. 26, 126-31. Del Campo, J.A., Garcia-Gonzalez, M., Guerrero, M.G., 2007. Outdoor cultivation of microalgae for carotenoid production: current state and perspectives. Appl. Microbiol. Biotechnol. 74, 1163-1174. Demirbas, A., 2005. Biodiesel production from vegetable oils via catalytic and non-catalytic supercritical methano l transesterification methods. Prog. Energy. Combust. Sci. 31, 466-487. Fukuda, H., Kondo, A., Noda, H., 2001. Biodiesel fuel production by transesterification of oils. J. Biosci. Bioeng. 92, 405-416. Gerpen, J.V., 2005. Biodiesel processing and production. Fuel Process. Technol. 86, 1097-1107. Hsieh, C.-H., Wu, W.-T., 2009. Cultivation of microalgae for oil production with a cultivation strategy of urea limitation. Bioresour. Technol. 100, 3921-3926. Hu, Q., Sommerfeld, M., Jarvis, E., Ghirardi, M., Posewitz, M., Seibert, M., Darzins, A., 2008. Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances. Plant J. 54, 621-639. Ip, P.F., Wong, K.H., Chen, F., 2004. Enhanced production of astaxanthin by the green microalga Chlorella zofingiensis in mixotrophic culture. Process Biochem. 39, 1761-1766. Knothe, G., 2005. Dependence of biodiesel fuel properties on the structure of fatty acid alkyl esters. Fuel Process. Technol. 86, 1059-1070. Knothe, G., Dunn, R.O., Bagby, M.O., 1997. Biodiesel: the use of vegetable oils and their derivatives as alternative diesel fuels. in: B.C. Saha, J. Woodward (Eds.), Fuels and Chemicals from Biomass. American Chemical Society, Washington, D.C., pp. 172-208. Lang, X., Dalai, A.K., Bakhshi, N.N., Reaney, M.J., Hertz, P.B., 2001. Preparation and characterization of bio-diesels from various bio-oils. Bioresour. Technol. 80, 53-62. Liu, Z.-Y., Wang, G.-C., Zhou, B.-C., 2008. Effect of iron on growth and lipid accumulation in Chlorella vulgaris. Bioresour. Technol. 99, 4717-4722. Ma, F., Hanna, M.A., 1999. Biodiesel production: a review. Bioresour. Technol. 70, 1-15. Meher, L.C., Vidya Sagar, D., Naik, S.N., 2006. Technical aspects of biodiesel production by transesterification--a review. Renew. Sustain. Energy Rev. 10, 248-268. Miao, X., Wu, Q., 2004. High yield bio-oil production from fast pyrolysis by metabolic controlling of Chlorella protothecoides. J. Biotechnol. 110, 85-93. Miao, X., Wu, Q., 2006. Biodiesel production from heterotrophic microalgal oil. Bioresour. Technol. 97, 841-846. Pruvost, J., Van Vooren, G., Cogne, G., Legrand, J., 2009. Investigati on of biomass and lipids production with Neochloris oleoabundans in photobioreactor. Bioresour. Technol. 100, 5988-5995. Shi, X.-M., Chen, F., 2002. High-yield production of lute in by the green microalga Chlorella protothecoides in heterotrophic fed-batch culture. Biotechnol. Prog. 18, 723-727. Sun, N., Wang, Y., Li, Y.-T., Huang, J.-C., Chen, F., 2008. Sugar-based growth, astaxanthin accumulation and carotenogenic transcription of heterotrophic Chlorella zofingiensis (Chlorophyta). Process Biochem. 43, 1288-1292. Zhang, Y., Dub, M.A., McLean, D.D., Kates, M., 2003. Biodiesel production from waste cooki ng oil: 1. Process design and technological assessment. Bioresour. Technol.


List of Research Outputs

Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Law Y.K. , Wang M. , Ma D.L. , Al-Mousa F., Michelangeli F., Cheng S.H., Ng M., To K.F., Mok O.Y.F., Ko Y.Y. , Lam S.K. , Chen S.F. , Che C.M. , Chiu P. and Ko B.C.B., Alisol B, a novel inhibitor of the SERCA pump, induces autophagy, ER-stress and apoptosis, Molecular Cancer Therapeutics . 2010, 9: 718-730.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng CY

List of Research Outputs

Cheng C.Y. , Wong E.W.P. , Yan H.H.N. and Mruk D.D. , Regulation of spermatogenesis in the microenvironment of the seminiferous epithelium: new insights and advances, Mol Cell Endocrinol . 2010, 315: 49-56.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents blood-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants , In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Cheng KW

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylate d derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylamide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng KW

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylamide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, Uni ted States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-65 . 2010.


Researcher : Cheng YY

List of Research Outputs

Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Rela ted Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.


Researcher : Cheung KW

List of Research Outputs

Dudgeon D. , Mantel S...K... and Cheung K.W. , Food-web structure in small streams: do we need different models for the tropics?, Journal of the North American Benthological Society . 2010, 29: 395-412.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitami ns against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.


Researcher : Cheung MMS

List of Research Outputs

Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.


Researcher : Chiu MY

List of Research Outputs

Wu S.S. , Tong E.S.P., van de Merwe J.P. and Chiu M.Y. , Effects of 1,2 dichlorobenzene on the growth, bioenergetics and reproduction of the amphipod Melita longidactyla, Chemosphere . 2010, 80: 20-27.


Researcher : Chow BKC

Project Title: A negative feedback loop involving bile acids and Small Heterodimer Partner in controlling secretin gene expression is a key to modulate bile release
Investigator(s): Chow BKC
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
(1) To substantiate the working model for regulating secretin gene expression by bile acids in mouse; (2) use secretin receptor WT and Ko mice to investigate 2a) in vivo functions of bile acids to negatively feeedback to control secretin gene expression: 2b) in vivo functions and cellular mechanisms of secretin in the liver to activate bile flow; (3) to investigate the potential of secretin to protect or prevent bile acids-induced liver damage.


Project Title: Discovery of novel growth hormone-r eleasing hormones in vertebrates: from functions to evolution
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: France/Hong Kong Joint Research Scheme - Travel Grants
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
1) To confirm the function of the newly discovered GHRH as GH-regulator in goldfish; 2) to consolidate the proposed evolutionary scheme for three important intercellular communicators, GHRH, VIP and PACAP.


Project Title: Discovery of novel growth hormone -releasing hormone: from functions to evolution
Investigator(s): Chow BKC
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Abstract:
To confirm the function of the newly discovered GHRH as GH-regulator in goldfish; to find putative function(s) of PRP in non-mammalian vertebrates; to consolidate the proposed evolutionary scheme for three important intercellular communicators, GHRH, PACAP and VIP, based on three rounds of genome duplication early on in vertebrate evolution.


Project Title: Neuron-restrictive silencer fact or (NRSF) regulates cell-specific expression of the human secretin receptor gene
Investigator(s): Chow BKC, Lee TO
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 03/2010
Abstract:
1. To identify the location and function of neuron-restrictive silencer element (NRSE) within the hSR promoter 2. To confirm the in vitro/in vivo binding of NRSF to NRSE 3. To study the role of NRSF, by interacting with Sp-proteins, in regulating hSR expression.


Project Title: A unified on-line learning portal for Majors and Minors offered by the newly formed Scho ol of Biological Sciences
Investigator(s): Chow BKC, Pointing SB, Wong AST, Wan JMF, Lo CSC , Hau CH, Gu JD
Department: School of Biological Sciences
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 09/2008
Abstract:
Purpose of the investigation To provide on-line learning support to all biological science courses that feed all the Major/Minor programmes offered by the School. This will be unique in that it’s design will create a constantly evolving resource with a simple interface that requires no programming knowledge to operate: Individual staff will have direct access to edit the web-based noticeboards, download centres, tutorial material etc. This will not only alleviate the burden of web support on technical staff but vitally it will have valuable benefits in academic staff developm ent within the School as all can become more engaged in the development on-line learning. The project will also reinforce development of a School culture, which is vital in the early days of a merged set of departments such as these. Students will gain from a centralized resource that will enrich and add real value to their learning. Modern biological sciences rely heavily on graphical explanations and multimedia tools to conve y concepts and techniques. This is particularly relevant to areas where safety and ethical issues in biology preclude traditional practical teaching. Added value will accrue as students will be able to identify a ‘brand’ associated with the new School, and this will help to foster collegiality among students and staff who have recently come together form different departments.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Central Administration of Secretin Suppresses Food Intake in Mice
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


Project Title: THE POTENTIAL ROLE OF SECRETIN, A POSTPRANDIALLY RELEASED GUT HORMONE, IN APPETITE CONTROL
Investigator(s): Chow BKC, Chan YS, Ng SM
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To demonstrate the role of central and peripheral secretin in appetite control; 2) To investigate mechan isms through which central and peripheral SCT modulates appetite; 3) To study pathways that secretin employs to stimulate/inhibit expression of anorexigenic/orexigenic peptides.


Project Title: Modulation of secretin and secretin receptor gene expressions by angiotensin II in mouse hypothalamic cells.
Investigator(s): Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Angiotensin II (Ang II) has diverse physiological actions leading, for example, to increases in extracellular volume, peripheral vascular resistance and blood pressure, and has also been implicated in the regulation of cell growth and differentiation. In brain, the intrinsic renin-angiotensin system (RAS) is important in regulati ng blood pressure and volume homeostasis. Immunohistochemical study suggested that a large number of Ang II immunoreactive fibers and Ang II receptors (AT1 receptor) are expressed in the hypothalamic paraventricular nucleus (PVN). Actually, magnocellular neurons of the hypothalamo- neurohypophysial system (HNS) play a fundamental role in the maintenance of body water homeostasis by regulating vasopressin (Vp) expression and its secretion from the posterior pituitary in response to systemic osmotic perturbations. Recent studies by our group, however, have found that secretin, in additional to Vp, could also be released from these neurosecretory cells, where transcription of the secretin gene, as well as its receptor (SCTR) gene, are activated by hyperosmolality (1). These data indicate that the increase of secretin expression results in thirst and hence polydipsia. Interestingly, the effects of secretin in brain under water deprivation are similar to those of Ang II. It is therefore possible that secretin may act as a mediating factor in the renin-angiotensin axis. In wild-type mice, centrally administration of Ang II significantly increased secretin and SCTR transcript levels in brain. More important, in metabolic cage study, Ang II-stimulated water intake was abolished in SCTR knock-out (SCTR-/-) mice. Therefore, we proposed that secretin is involved as a component within the RAS. In our data using N42 cells, the expression levels of both secretin and SCTR were increased by treatment of Ang II. Although it has clearly been established that Sp1/Sp3 ratio and the methylation status of the promoter contribute to the expressions of both genes (2,3), the precise molecular mechanism underlying the induction of these two genes in response to Ang II has not been clarified. The present study therefore aims to identify the osmotic response elements in the secretin and SCTR promoters. To investigate the mechanism that activates secretin and secretin receptor genes after Ang II treatment, three objectives are proposed: (1) Mapping of the cis-acting elements of secretin and SCTR promoters (2) Identification of the transcription factors that mediate the osmotic response (3) Functional analysis of proposed pathways by specific inhibitors and gene silencing technique


List of Research Outputs

An X. , Ng S.M. , Xie D., Zeng Y.X., Sze J. , Wang J. , Chen Y.C., Chow B.K.C. , Lu G., Poon W.S., Kung H.F., Wong B.C.Y. and Lin M.C. , Functional characterisation of cell cycle-related ki nase (CCRK) in colorectal cancer carcinogenesis. , European Journal of Cancer . 2010, 46: 1752-1761.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Rel ated Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Lam P.Y. , Glasser G., Gaudio E., Chow B.K.C. , Onori P., Franchitto A., Carpino G., Venter J., Francis H., Mancinelli R., Kopriva S. and Alpini G., Knock out of secretin receptors reduces large cholangiocyte hyperplasia in mice with extrahepatic cholestasis ind uced by bile duct ligation., Hepatology . 2010, 52: 204-214.
Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Vaudry D., Falluel-Morel A., Bourgault S., Basille M., Burel D., Wurtz O., Fournier A., Chow B.K.C. , Hashimoto H., Galas L. and Vaudry H., Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery., Pharmacological Reviews . 2009, 61: 283-357.
Yao H. , Ng S.M. , Tucker W.O. , Tsang Y.K.T. , Man K. , Wang X.M., Chow B.K.C. , Kung H.F., Tang G. and Lin M.C. , The gene transfection efficiency of a folate-PEI600-cy clodextrin nanopolymer, Biomaterials . 2009, 30(29): 5793-5803.


Researcher : Chu H

List of Research Outputs

Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essential for chloroplast function., New Phytologist . 2010, 187: 83-105.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Chu JYS

Project Title: Identification of the first non-mammalian secretin and secretin receptor: functional evolution of this ligand-receptor pair in the transition process from aquatic to terrestrial life
Investigator(s): Chu JYS, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 09/2008
Completion Date: 02/2010
Abstract:
Secretin is the first hormone discovered in the human history. It has well-established functions in the gastrointestinal tract and central nervous system, and has recently been shown to act also as an anti-diuretic peptide in mammals. In non-mammalian vertebrates, howev er, virtually nothing is known about their sequence, structure, function, signaling mechanisms, and evolutionary origin. Recent advents in various genome projects have provide us the opportunity to identify candidate genes for this ligand-receptor pair in lower vertebrates via comparative approaches, including sequence similarity searches. One significant finding is that putative orthologous for secretin and its receptor could only be identified in tetrapods but not teleosts (Figure 1). As secretin has recently been shown to modulate body water homeostasis in mammals by regulating renal water reabsorption, we hypothesized that this ligand-receptor pair was evolved during the transition from aquatic to terrestrial habitats to deal with problems related to desiccation. The present project therefore aims to: 1) Isolate and characterize secretin and its receptor from a nonamniote vertebrate, Xenopus laevis, an amphibian that occupies a critical phylogenetic position mid-way between ascidians and mammals. 2) Investigate the functional evolution of this ligand-receptor pair in vertebrate.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Secretin: A neurosecretory factor regulating body water homeostasis
Investigator(s): Chu JYS
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


List of Research Outputs

Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Central administration of secretin suppresses food intake in mice, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Cheng Y.Y. , Chu J.Y.S. and Chow B.K.C. , Vasopressin-independent mechanisms in controlling water homeostasis, J Mol Endocrinol . 2009, 43: 81-92.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.


Researcher : Chye ML

Project Title: Investigations on stress-inducible Arabidopsis acyl-CoA binding proteins
Investigator(s): Chye ML
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Abstract:
To select a lead-binding ACBP and to verify feasibi lity of its application in phytoremediation; to study Arabidopsis ACBP3 in response to phytopathogen stress and to verify its use in protection against phytopathogens.


Project Title: Outstanding Researcher Award 2006-2007
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Researcher Award
Start Date: 11/2007
Abstract:
Nil


Project Title: Characterization of a cDNA encoding a 71-kD rice acyl-CoA-binding protein
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Completion Date: 03/2010
Abstract:
Purpose: Acyl-CoA-binding proteins (ACBPs) show conservation in the acyl-CoA-binding domain and thus they can bind and transport acyl-CoA esters in lipid metabolism. The aim of this project is to characterize a potentially unusual member belonging to the family of ACBPs in the monocot, rice (Oryza sativa). This particular rice ACBP, designated OsACBP1, has a predicted chloroplast targeting sequence and two potential transmembran e domains. At present, no chloroplast targeting sequence has been identified in known plant ACBPs. In plants, de novo fatty acid biosynthesis occurs in the chloroplast and acyl-CoAs (oleoyl-CoA and palmitoyl-CoA) esters are subsequently transported via the cytosol to the endoplasmic reticulum (ER) for non-plastidial lipid metabolism. Presence of a chloroplast form of ACBP would indicate that OsACBP1 may function in acyl-CoA trafficking within the chloroplast and suggests a new role for ACBPs in this subcellular compartment. In the dicot model plant, Arabidopsis, we have characterized a family of six ACBPs but none of these include a chloroplastic form. ACBP4 and ACBP5 are candidates that mediate the cytosolic transfer of oleoyl-CoA esters originating from the chloroplast to the ER, based on our observations that recombinant His-tagged ACBP4 and ACBP5 bind oleoyl-CoA esters in vitro. In this project we will characterize the putative chloroplastic form of ACBP from rice. We will test if the predicted chloroplast targeting sequence in OsACBP1 functions in directing it to the chloroplast by using a Green Fluorescent Protein (GFP) autofluorescence tag in transient expression assays on subcellular localization. Further, we will identify the acyl-CoA esters that bind OsACBP1 in in vitro binding assays using recombinant His-tagged OsACBP1 expressed in E. coli. A His-tag will be fused to OsACBP1 to facili tate easy purification of the recombinant protein in mass production for in vitro assays with oleoyl-CoA and palmitoyl-CoA. Key issues: In Arabidopsis, six ACBPs have been identified and characterized (Leung et al., 2004). They, designated ACBP1 to ACBP6, have been subcellularly localised to various compartments but none is targeted to the chloroplast. ACBP1 and ACBP2 are localized in the plasma membrane (Chye et al., 1999; Chye et al., 2000; Li and Chye, 2003; 2004), ACBP3 is extracellularly-targeted (Leung et al., 2006) and ACBP4, ACBP5 and ACBP6 are cytosolic proteins (Leun g et al., 2004; Chen et al., 2008). These ACBPs differ in molecular mass, ranging from 10 to 73 kDa and substrate specificities for acyl-CoA esters (Leung et al., 2004; Gao et al., 2008). We have demonstrated that the genes encoding Arabidopsis ACBP1, ACBP2, ACBP3, and ACBP6, are subject to regulation by various forms of abiotic and biotic stress (Chen et al, 2008; Gao et al, 2008; Li et al., 2008; Xiao et al, 2008a, 2008b). The overexpression of ACBP1 or ACBP2 in transgenic Arabidopsis resulted in tolerance to heavy metal str ess and oxidative stress because ACBP1 and ACBP2 are associated with membrane repair (Xiao et al, 2008a; Gao et al, 2008). ACBP3-overexpressing transgenic Arabidopsis show enhanced resistance to pathogens while ACBP6-overexpressin g transgenic Arabidopsis are conferred freezing tolerance (Chen et al, 2008). ACBPs mediate lipid transfer and the manipulation of lipid composition has resulted in stress-tolerance. These initial investigations on the model plant, Arabidopsis, have many advantages including the availability of its complete genome sequence and knock-out mutants. Further, Arabidopsis has a rapi d life-cycle, is easy to transform and maintain in the laboratory. If we were to carry out similar investigations on rice, it would have taken us a longer time to achieve similar results in understanding the role of plant ACBPs because rice is difficult to transform and knock-out mutants are not easily accessible. Our eventual goal is to genetically-modify rice to stress-resistance by manipulation of the rice genome using Arabidopsis ACBPs. But before we can overexpress Arabidopsis ACBPs in transgenic rice to obtain these stress-resistant varieties by application of the principles used in the generation of stress-tolerant transgenic Arabidopsis, we should first attempt to acquire basic knowledge on the endogenous ACBP family in rice. From GenBank data, we have identified six rice genes that encode proteins conserved in the acyl-CoA binding domain. Of these, three resemble Arabidopsis ACBP6, because they consist only of an acyl-CoA-binding domain. Another has ankyrin repeats and a membrane domain, resembling Arabidopsis ACBP1 and ACBP2. However, the largest rice ACBP (71-kD), designated OsACBP1, possesses an unusual predicted structure in comparison to all known plant ACBPs. Computer predictions suggest that OsACBP1 contains kelch motifs, (resembling ACBP4 and ACBP5), as well as two transmembrane domains and an N-terminal chloroplast targeting sequence. The presence of two predicted transmembrane domains and a potential chlorop last targeting sequence is novel to plant ACBPs. There have been no reports of any ACBP subcellularly localized in the chloroplast. Problems addressed: The problems addressed in this project are: 1. to establish if the predicted chloroplast targeting sequence in OsACBP1 is functional; 2. to identify the acyl-CoA esters that bind OsACBP1. Although fatty acid biosynthesis initiates from within the chloroplast, none of our previously characterized Arabidopsis ACBPs have been localized to this subcellular compartment. Since rice is a monocot, unlike Arabidopsis, it may possibly have evolved a chloroplastic form of ACBP to facilitate an efficient transfer of acyl-CoA esters within the chloroplast to cytosolic ACBPs. To establish if the predicted chloroplast targeting sequence of OsACBP1 functions in targeting to the chloroplast, its N-terminal predicted targeting sequence consisting of the first 30 amino acids will be fused in-frame to autofluorescent protein GFP. Also, the full-length OsACBP1 peptide will be fused in-frame to GFP as comparison. The acyl-CoA substrates that bind OsACBP1 will be identified using in vitro binding assays. Oleoyl-CoA and palmitoyl-CoA will be tested because they are generated from de novo fatty acid biosynthesis inside chloroplasts. References: 1. QF Chen, S Xiao and ML Chye. 2008. Plant Physiology 148: 304-315. 2. ML Chye, BQ Huang and SY Zee. 1999. Plant Journal 18: 205-214. 3. ML Chye, HY Li and MH Yung. 2000. Plant Mol Biol: 44: 711-721. 4. W Gao, S Xiao, HY Li and ML Chye. 2008. New Phytologist doi: 10.1111/j.1469-8137.2008.02631.x 5. KC Leung, HY Li, G Mishra and ML Chye. 2004. Plant Mol Biol 55: 297-309. 6. KC Leung, HY Li, S Xiao, MH Tse, ML Chye. 2006. Planta 223: 871-881. 7. HY Li and ML Chye. 2003. Plant Mol Biol 51: 483-492. 8. HY Li and ML Chye. 2004. Plant Mol Biol 54: 233-243. 9. HY Li, S Xiao and ML Chye. 2008. J. Exp. Bot. 59: 3997-4006. 10. S Xiao, W Gao, QF Chen, S Ramalingam and ML Chye. 2008a. Plant Journal 54: 141-151. 11. S Xiao, HY Li, JP Zhang, SW Chan and ML Chye. 2008b. Plant Mol. Biol. 68: 571-583.


Project Title: The Third Asian Symposium on Pla nt Lipids (ASPL 2009) ARABIDOPSIS ACYL-COENZYME-A BINDING PROTEIN 2 INTERACTS WITH A LYSOPHOSPHOLIPASE
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 11/2009
Completion Date: 11/2009
Abstract:
N/A


Project Title: Analysis of transgenic model plants
Investigator(s): Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Purpose: Plant isoprenoids include natural compounds that promote physiological functions and defense against phytopathogens. 3-Hydroxy-3-methyl-glutaryl-CoA synthase (HMGS) is an enzyme in isoprenoid biosynthesis in eukaryotes and some bacteria. The aim of this project is to address whether isoprenoid production can be increased in transgenic plants by the overexpression of wild-type/mutant HMGS. It will also show whether physiological functions (e.g., plant growth and development) and defense against phytopathogens are consequently enhanced in HMGS-overexpressors. Key issues: Isoprenoids are one of the largest classes of natural products including sterols, sesquiterpenes, polyterpenes, carotenoids, taxol and artemisinin, and are mainly produced by plants (Bach, 1995; Roberts, 2007). Plant isoprenoids are essential for membrane biogenesis (sterols), photosynthesis (carotenoids, chlorophyll), respiration (quinones), growth and development (abscisic acid an d gibberellic acid) and in disease resistance (sesquiterpenes, brassinosteroids), and they also play significant roles in plant-environment interactions, plant-plant communication , and plant-insect interactions (Bach, 1995; Pichersky and Gershenzon, 2002). Isoprenoids such as natural rubber are economically valuable while monoterpenes (e.g., linalool) are used as flavors/fragrances in food additives. Taxol and artemisinin are important anti-cancer drugs while artemisinin is anti-malarial too. The important functions of many isoprenoids make it useful for them to be overproduced in transgenic plants. Two biosynthetic pathways synthesize isoprenoid precursors in plants, the cytosolic mevalonate (MVA) pathway (Bach 1995) and the plastid-confined non-MVA pathway (Lichtenthaler 1999; Rohmer 1999). The MVA pathway provides isoprenoids essential for growth, development and defense (Bach, 1995; Hemmerlin and Bach 1998; Hemmerlin et al. 1999). Both HMGS and HMG reductase (HMGR, Kush et al., 1990; Chye et al., 1992) catalyze the early steps in the MVA pathway. HMGS catalyzes the condensation of acetyl-CoA with acetoacetyl-CoA (AcAc-CoA) to yield HMG-CoA and HS-CoA while HMGR converts HMG-CoA to MVA. My laboratory has cloned and characterized cDNAs encoding four isoforms of Brassica juncea HMGS, designated BjHMGS1 to BjHMGS4 (Alex et al., 2000; Nagegowda et al., 2004; 2005). Brassica HMGS expression is stress-inducible and is highly expressed during early development in flower, seed and seedling, indicative of its role in development (Alex et al., 1999). Although BjHMGS1 to BjHMGS4 are highly-conserved, they are differentially expressed during floral and seedling development (Nagegowda et al., 2005). BjHMGS1 was localized in the cytosol by confocal microscopy and western blot analysis of subcellular protein fractions from transgenic plants expressing Green Fluorescent Protein-tagged BjHMGS1 (Nagegowda et al., 2005). The structure of BjHMGS1 in molecular interaction with its inhibitor F-244 has been elucidated to explore the potential of using HMGS as an alternative target for anti-cholesterol and antibiotic drugs, given that MVA is a precursor of cholesterol in mammals and HMGS inhibition adversely affects bacterial viability (Pojer et al., 2006). We first report on the biochemical characterization of a plant-derived HMGS using bacterial-expressed recombinant (His)6-tagged BjHMGS1 (Nagegowda et al., 2004). Catalytic residues in BjHMGS1 were identified by site-directed mutagenesis (Nagegowda et al., 2004). (His)6-BjHMGS1 was inhibited by one of the substrates (AcAc-CoA) and by both products (HMG-CoA and HS-CoA). Site-directed mutagenesis of conserved amino acid residues in BjHMGS1 revealed tha t substitutions R157A, H188N and C212S resulted in a decreased Vmax, indicating some involvement of these residues in catalytic capacity. Unlike (His)6-BjHMGS1, the H188N mutant did not display substrate inhibition by AcAc-CoA. Substitution S359A resulted in a 10-fold increased specific activity. Subsequently, we generated a novel double mutation H188N/S359A, which resulted in a 10-fold increased specific activity, but still lacking inhibition by AcAc-CoA, strongly suggesting that H188 is involved in conferring substrate inhibitio n to (His)6-BjHMGS1 (Nagegowda et al., 2004). The identification of BjHMGS1 mutants which are substrate insensitive and show enhanced enzymatic activity (Nagegowda et al., 2004) provides us the tools for the metabolic engineering of isoprenoids. Investigations on the over expression of these mutant BjHMGS1 in model plants is a first step towards this end. Specifically, this project will investigate the effects in the overexpression of wild-type and mutant (H188N, S359A and H188N/S359A) BjHMGS1 in model plants, Arabidopsis and tobacco. The following problems will be addressed: 1. Does the overexpression of wild-type or mutant BjHMGS1 improve isoprenoid accumulation in model plants and if it does, what is the identity of the isoprenoid compounds that accumulate? 2. Which version (wild-type/mutant) of BjHMGS1 is most effective in causing isoprenoid accumulation when overexpressed in transgenic plants? 3. Does the overexpression of wild-type/mutant BjHMGS1 affect plant growth, development and defense against phytopathogens? To examine isoprenoid accumulation, isoprenoid products such as the various plant sterols (campesterol, sitosterol and stigmasterol) and sesquiterpenes will be measured in transgenic Arabidopsis and tobacco lines. Plant sterols will be measured because they are useful as functional foods as they can block intestinal cholesterol adsorption and lower cholesterol in humans (Ostlund et al., 2003). Sitosterol further promotes plant growth and development while sesquiterpenes enhance plant defense. Transgenic Arabidopsis and tobacco will also be examined for changes in growth using germinating seedlings, and for any improved disease resistance to Botrytis cinerea (fungal pathogen). These proposed investigations using model plants are prerequisite to the application of wild-type/mutant BjHMGS1 in tra nsgenic Artemisia which produces artemisinin (a sesquiterpene) via the MVA pathway or in crops for improved growth and protection against phytopathogens, as well as for the production of sterol-enriched plant products in functional foods to control cholesterol adsoprtion. References: 5-year IF(2008):PNAS 10.228;Plant J 6.951;Plant Physiol 6.650;Biochem J 4.251;Plant Mol Biol 3.901;Planta 3.304 1. Alex D, Bach TJ, Chye ML (2000) Plant J 22:415-426. 2. Bach TJ (1995) Lipids 30:191-202. 3. Chye ML, Tan CT, Chua NH (1992) Plant Mol Biol 19: 473-484. 4. Dhawan R et al. (2009) Plant Cell 21:1000–1019. 5. Ferrari S et al. (2003) Plant J 35:193-205. 6. Hemmerlin A, Bach TJ (1998) Plant J 14:65-74. 7. Hemmerlin A et al., (1999) Acta Bot Gall 146:85-100 8. Kush A, Goyvaerts E, Chye ML, Chua NH (1990) Proc Natl Acad Sci USA 87:1787- 1790. 9. Lichtenthaler HK (1999) Annu Rev Plant Physiol Plant Mol Biol 50:47-65. 10. Nagegowda DA, Bach TJ, Chye ML (2004) Biochem J 383:517-527. 11. Nagegowda DA, Ramalingam SK, Hemmerlin A, Bach TJ, Chye ML (2005) Planta 221:844-856. 12. Ostund RE et al. (2003) American J Clin Nutr 77:1385-1389. 13. Pichersky E, Gershenzon J (2002) Curr. Opin. Plant Biol. 5: 237-243. 14. Pojer F, Ferrer JL, Richard SB, Nagegowda DA, Chye ML, Bach TJ, Noel JP (2006) Proc Natl Acad Sci USA 103:11491-11496. 15. Roberts SC (2007) Nature Chemical Biology 3: 387-395. 16. Rohmer M (1999) Nat Prod Rep. 16:565-574. 17. Schaller H, Grausem B, Benveniste P, Chye ML, Tan CT, Song YH, Chua NH (1995) Plant Physiol 109:761- 770.


List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Arabidopsis acyl-Coenzyme A-binding proteins, American Oil Chemists Society (AOCS) Lipid Library, Plant Lipid Biochemistry . 2010.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Chye M.L. , Editorial Advisory Board, The Open Plant Science Journal (Bentham Science Publishers) . 2010.
Chye M.L. , Editorial Board, Botanical Studies (Institute of Plant and Microbi al Biology, Academia Sinica) . 2010.
Chye M.L. , Editorial Board, Journal of Botany (Hindawi Press) . 2010.
Chye M.L. and Zhao K.J., Genetically modified plants with enhanced resistance to fungal disease and a method of production thereof, Chinese Patent ZL02822987.8 issued Oct 14, 2009 . 2009.
Chye M.L. , Member (Editor), Planta Editorial Board, Planta, Springer-Verlag GmbH . 2009.
Chye M.L. , Member, Editorial Advisory Board, The Open Plant Science Journal, Bentham Science Publishers . 2009.
Chye M.L. , Member, Editorial Board, Botanical Studies (Institute of Plant and Microbial Biology, Academia Sinica) . 2009.
Chye M.L. , Member, Editorial Board, Journal of Botany (Hindawi Press) . 2009.
Chye M.L. , Planta Editorial Board, Planta (Springer-Verlag) . 2010.
Chye M.L. , Tolerant to cold snaps, HKU Pavilion, InnoCarnival, Innovation Festival, Science Park. 2009, 5th - 8th Nov, 2009 .
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Ubhayasekera W., Rawat R., Ho S.W.T. , Wiweger M., Von Arnold S., Chye M.L. and Mowbray S., The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce, Plant Molecular Biology . 2009, 71: 277-289.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidylcholine and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Resear ch, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Corke H

Project Title: 2nd International Wheat Quality Conference Effect of Wheat Quality on Noodle Production
Investigator(s): Corke H
Department: Botany
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2001
Abstract:
N/A


Project Title: Molecular markers for starch content and quality in rice
Investigator(s): Corke H
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 11/2006
Completion Date: 10/2009
Abstract:
To develop gene-tagged markers and their integration into a genetic linkage map, and mapping OTL for starch content and quality (structural and functional properties); to sequence major genes, analysis of gene diversity and linkage disequilibrium, and association mapping of the genes in relation to starch content and quality; to develop a protocol for marker-assisted selection to most effectively simulate multiple components contributing to high starch contents and desired starch properties in Chinese rice breeding and therefore with direct applicability to economic development in China.


Project Title: ASA-CSSA-SSSA International Annual Meetings 2009 Molecular markers for starch quality of rice
Investigator(s): Corke H
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 11/2009
Completion Date: 11/2009
Abstract:
N/A


List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocyanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food : Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Cai Y. , Ke J.X. and Corke H. , MALDI-QIT-TOF MS determination of proanthocyanidins in crude extracts of selected dietary plants and medi cinal herbs (Abstract), Global Chinese Health (Functional) Food Symposium 2009 (Hong Kong) . 2009.
Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw pork, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Xiong G.Q., Cheng W., Ye L.X., Du X., Zhou M., Lin R.T., Geng S.G., Chen M.G., Corke H. and Cai Y. , Effects of konjac glucomannan on physicochemical properties of myofibrillar protein and surimi gels from grass carp ( Ctenopharyngodon idella ), Food Chemistry . 2009, 116 (2): 413-418.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/gluco se model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Du Y

List of Research Outputs

Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-induci ble flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Du Y. and Lo C.S.C. , Molecular characterizatiom of a flavone synthase gen e in sorghum, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deo xyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Micr obe Interactions . 2009.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.


Researcher : Du Z

List of Research Outputs

Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.


Researcher : Dudgeon D

Project Title: The conservation of freshwaters in tropical Asia
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 01/2002
Abstract:
To write a book setting out the conservation status of lake and river ecosystems in the oriental tropics, for publication by Backhuys Press in 2004.


Project Title: The ecology and biodiversity of Hong Kong
Investigator(s): Dudgeon D, Corlett RT
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 07/2002
Abstract:
To produce a revised edition of Dudgeon and Corlett (1994) "Hills and streams: an ecology of Hong Kong" for simultaneous publication in Chinese nd English.


Project Title: Tropical stream ecology
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 01/2003
Abstract:
To produce a multi-authored volume focused on comparison of streams among tropical regions on a topic-by-topic basis; to summarise what is known by highlighting similariti es among regions (particularly the ecological responses to a climatic backdrop of wet versus dry seasons, plus temperature close to the biological optimum), and to account for any consistent patterns of difference that emerge; to highlight what we do not know, and suggest ways of filling these knowledge gaps in a subsection of each chapter entitled 'future research directions and information needs'.


Project Title: Conservation of freshwater biodi versity in Asia
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 06/2003
Abstract:
To write a book for discussing the issues and implications of damages and pollution causes by human beings.


Project Title: Scale-specific inter-population variation in the proteomics of Caridina shrimps in Hong Kong
Investigator(s): Dudgeon D, Chan LL
Department: Ecology & Biodiversity
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To understand whether molecular differences revealed by RAPD are adaptations to local conditions, or merely a reflection of non-adaptive variation, we must stud y what proteins are actually present in each population.


Project Title: Biodiversity and ecosystem functioning in Hong Kong streams
Investigator(s): Dudgeon D
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
To establish the functional role of invertebrates associated with leaf litter; to test the relationship between shredder diverstiy and detritus processing rates along a gradient of stream characteristics; to determine the relationship between leaf quality, shredder diversity and detritus processing rates; field studie s to determine the effects of changed flow regimes on shredder diversity and detritus processing rates; to use artificial stream channels to determine the effects of shredder diversity, changed flow regimes and water temperature on detritus processing rates; to establishment of the relationship between shredder diversity and detritus processing rates using field microcosms and laboratory experiments.


List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.
Dudgeon D. , Associate Editor, Hydrobiologia (2002-present), 2009.
Dudgeon D. , Associate Editor, Aquatic Sciences . 2010.
Dudgeon D. , Associate Editor, Hydrobiologia . 2009.
Dudgeon D. , Editorial Board, Aquatic Conservation: Marine and Freshwater Ecosystems . 2009.
Dudgeon D. , Editorial Board, Freshwater Biology . 2009.
Dudgeon D. , Editorial Board, River Research and Applications . 2009.
Dudgeon D. , Mantel S...K... and Cheung K.W. , Food-web structure in small streams: do we need different models for the tropics?, Journal of the North American Benthological Society . 2010, 29: 395-412.
Dudgeon D. , Freshwater Biodiversity in the Anthropocene , DIVERSITAS OCS2: Biodiversity and Society – Understan ding Connections, Adapting to Change 2009 (Capetown, South Africa) . 2009.
Dudgeon D. , Member, Editorial Board of Aquatic Conservation: Marine and Freshwater Ecosystems (1998-present), 2009.
Dudgeon D. , Member, Editorial Board of Freshwater Biology (2007-present), 2009.
Dudgeon D. , Member, Editorial Board of Freshwater Biology (2007-present), 2009.
Dudgeon D. , Member, Editorial Panel of River Research and Applications (formerly Regulated Rivers: Research and Management) (1994-present), 2009.
Dudgeon D. , Requiem for a river: extinctions, climate change and the last of the Yangtze., Aquatic Conservation: Marine and Freshwater Ecosystems . 2010, 20: 127-131.
Dudgeon D. , Subject Editor, Biotropica (2001-2007), 2009.
Dudgeon D. , Tropical Asian Rivers in times of change, 10th International Congress of Ecology (INTECOL) 2009 (Brisbane, Australia) - invited but unable to attend. . 2009.
Dudgeon D. , • SIL Symposium on Global Change and Freshwater Environments 2009 (Nanjing, China): Into the Anthropocene: freshwater biodiversity in China – plenary lecture., 2009.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predator on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Annual Meeting of the Society for Conservation Bio logy . 2009.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Joint Annual Meeting of Ichthyologists and Herpeto logists . 2009.
Kwong K.L., Dudgeon D. , Wong P.K. and Qiu J.-.W., High secondary production and diet of an invasive snail in freshwater wetlands: implications for resource co nsumption and competition. , Biological Invasions . 2010, 12: 1153-1164.
Naiman R...J... and Dudgeon D. , Global alteration of freshwaters and influences on human and environmental well-being., Ecological Research . 2010, 25: DOI 10.1007/s11284-010-0693-3.
Strayer D. and Dudgeon D. , Freshwater biodiversity conservation: recent progress and future challenges., Journal of the North American Benthological Society . 2010, 29: 344-358.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Yang Y. and Dudgeon D. , Dietary variation and food selection by an algivorous loach (Pseudogastromyzon myersi: Balitoridae) in Hong Kong streams., Marine and Freshwater Research . 2010, 61: 49-56.
Yang Y. and Dudgeon D. , Response of grazing impacts of an algivorous fish (Pseudogastromyzo n myersi: Balitoridae) to seasonal disturbance in Hong Kong streams. , Freshwater Biology . 2010, 55: 411-423.
Yang Y. and Dudgeon D. , Spatial and seasonal variations in benthic algal assemblages in streams in monsoonal Hong Kong., Hydrobiologia . 2009, 632: 189-200.
Zhang Y. and Dudgeon D. , Impacts of deforestation and hydrological change on river ecosystems in Southeast Asia. , In: L. Lebel, A. Snidvongs, C.-T. A. Chen & R. Daniel, Critical States: Environmental Challenges to Development in Monsoonal Southeast Asia . Petaling Jaya, Malaysia, , Strategic Information and Research Development Centre, 2009, 268-280.


Researcher : Dumont C

Project Title: Functional importance of sea urchins and coral-feeding invertebrates on bioerosion of corals
Investigator(s): Dumont C
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Completion Date: 09/2010
Abstract:
Over the last decades, coral reef ecosystems have undergone widespread declines due to storms, predation, bleaching, disease and anthropogenic disturbances (Hughes et al. 2003, Pandolfi et al. 2003, Mora et al. 2006, Mumby et al. 2006, De'ath et al. 2009). Direct consumption of live coral, or corallivory, represents a biotic stressor that can adversely affect coral fitness and accelerate rates of coral decline (Rotjan et al. 2006). In addition to being coral predators, some corallivores and others grazers (e.g. sea urchins) may also act as bioeroders (consumers of dead coral substrate) which are known to play an important role in coral reef dynamics by eroding skeletons of corals, yet little attention has been paid to the diverse roles corallivores and grazers might play in maintaining a complex of interactions influencing the structure of corals reef communities. The corallivorous gastropods Drupella spp. and the crown-of-thorns seastar Acanthaster planci are known as agents of large-scale disturbance to coral reefs (Turner 1994, Carpenter 1997). Population outbreaks have been reported at various Indo-West Pacific location s (e.g. Malaysia, Hong Kong and Japan) and a number of studies correlate the high density of these corallivores with a drastic reduction in coral cover (reviewed by Endean & Cameron 1990). The suggested causative factors responsible for these outbreaks are numerous and include over-fishing, pesticide use, atomic testing, rain fore st depletion, global climate change, and over-population (Endean & Cameron 1990, Sapp 1999). Regardless of the cause, Drupella and Acanthaster feed on live coral tissue, leaving white feeding scars and aggregations often cause as much as 95% coral mortality in a localized area (Carpenter 1997). Facultative corallivores, both the sea star A. planci and the snails Drupella spp. preferentially consume live tissues of Montipora and Acropora corals but avoid feeding on only few sclerac tinian species (Morton & Blackmore 2000, Pratchett 2007). Numerous experimental studies based on the exclusion of herbivores from areas of reefs have demonstrated the importance of macroherbivores on patterns of algal communities. On a large scale, the effects of removal of the herbivore sea urchin Diadema antillarum in the Carribbean with the spread of a disease has further highlighted the importance of the role that sea urchins play in controlling algal communities and in maintaining an healthy balance between corals and algae (Lessios 1988, Edmunds & Carpenter 2001). On the other hand, sea urchins, and especially diadematids, are considered to also act as bioeroders, playing an important role in coral reef dynamics (Bak 1990, 1994, Carreiro-Silva & McClanahan 2001). While grazing on algae growing on dead corals, sea urchins also remove calcium carbonate with its very powerful jaw apparatus which may weaken the structure of cora l colonies but it remains unclear whether Diadema readily consumes live corals (i.e. facultative corallivorous). Considering that sea urchins can act as an herbivore and bioeroder, the role of sea urchins in reef trophodynamics is probably more complex than appreciated previously. The functional role of sea urchins in coral decline is controversial, having an important role in preventing alga overgrowth on corals and on the other hand the bioerosion of corals while grazing. A manipulative experiment in French Polynesia revealed that an increase of the density of the sea urchin Echinometra mathaei reduced the algae cover on the coral Acropora pulchra but also increase its bioerosion (Mapstone et al. 2007). More interestingly, the removal of sea urchins resulted to a similar algae cover than the treatment with natural urchin densities but an increase in coral mortality occured. It remains unclear the reasons of this increase of coral mortality but the authors suggest that the reduction of grazing pressure by urchins may have been responsible to an increase of boring invertebrates on dead corals that are normally removed by urchin grazing. Thus, we could hypothesize that urchins may primarily graze on fouling growing on dead corals pr eviously preyed by corallivorous (i.e. Drupella spp., Acanthaster planci), yet no studies examined the corallivore-herbivore-cor al interactions. The present study will address these gaps in our understanding by focusing on the functional role of these coral-feeding invertebrates (Drupella spp. and Acanthaster planci), and the grazing impact of the sea urchin Diadema setosum on bioerosion of coral reefs. In particular, we address the following questions: (1) What is the functional role of sea urchins and coral-feeding invertebrates on coral reefs? (2) Do corallivorous invertebrates facilitate bioerosion of corals by sea urchins? (3) How important is the grazing impact of sea urchins in the bioerosion of coral reefs? (4) What are the consequences of an abrupt decrease (manually removal) of coral-feeding predators (Drupella spp. in Hong Kong and Acanthaster planci in Malaysia) and Diadema setosum population? The answers to these questions will help understanding which functional role sea urchins and corallivorous gastropods have on coral reefs. The ability to understand the role and relative importance of the herbivorous and coralivorous invertebrates requires an understandin g of the quantitative impact of each species, their respective roles and interactions. We won’t be able to answer all the questions mentioned within this short-term proposal but the aim of the present study is to explore the interaction of coral invertebrate predators and grazers in the bioerosion of coral reefs and bring preliminary data to further explore hypotheses and write a strong proposal for further funding. We will therefore conduct our study with the following objectives : (1) Determine abundance and distribution of the herbivore Diadema setosum and corallivorous invertebrates on coral reefs (2) Examine the diet of the sea urchin Diadema setosum and the gastropods Drupella spp. and Cronia margariticola on coral reefs (3) Quantify the impact of corallivorous invertebrates and sea urchins on bioerosion of coral reefs.


Project Title: Mechanisms maintaining the coexistence of sea urchins in a seasonal subtropical rocky habitat
Investigator(s): Dumont C, Wai TC, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2009
Abstract:
1) To determine intra-and inter-specific variation in niche partitioning of the sea urchins Anthocidaris crassispina and Diadema setosum; 2) To examine the effect of fishing pressure on niche partitioning of the sea urchins Anthocidaris crassispina and Diadema setosum; 3) To examine the competitive ability of the urchin species and their interactions under shared predation.


List of Research Outputs

Dumont C. and Alfian K., Corals at risk: Effectiveness of the removal of a keystone coral-predator Acanthaster planci in a marine park of Malaysia. , 2nd Asia Pacific Coral Reef Symposium . 2010.
Dumont C. , Resistance of marine communities to human-facilitated invasion, Banyuls Marine Observatory, France . 2010.
Thiel M., Chak S.T.C. and Dumont C. , Mating behavior of the dancing shrimp Rhynchocinetes brucei (Decapoda: Caridea), Journal of Crustacean Biology . 2010, 33: 580-588.


Researcher : Dvornyk V

Project Title: Microevolution of circadian genes in cyanobacteria under long-term natural stress
Investigator(s): Dvornyk V
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2008
Completion Date: 09/2010
Abstract:
The overall objective of the proposed project is to study microevolution of the circadian clock system in cyanobacteria experiencing long-term complex natural stress and to determine factors having contributed to this evolution. This proposal encompasses the approaches of molecular genetics, genomics, and evolution and efficiently utilizes PI’s expertise in these fields. The hypothesis is: Microevolution of the circadian clock system in cyanobacteria under acute natural stress is primarily adaptive. The major goals are to determine: 1. Intra- and interslope polymorphisms in the studied genes. This will shed light on probable evolutionary forces that shape these polymorphisms under stress. 2. Intra- and interpopulation polymorphisms in the studied genes. This will help to distinguish population-specific adaptations from those common for the populations from both ECs. 3. Polymorphism in the previously identified functional domains of the genes under study. Accomplishment of this goal will help to identify functional significance of the domains (regions) in adaptation of cyanobacteria to complex natural stress. To reach the goals, the following specific aims will be fulfilled: 1. Sequencing 7 of the currently known circadian genes from 80 strains of N. linckia sampled on the opposite slopes of both ECs. To sequence partially the 16S rRNA genes from the same strains for the comparative evolutionary analysis. 2. Conducting a comprehensive evolutionary analysis of the sequenced genes and to estimate contribution of various evolutionary factors to the observed pattern s of nucleotide polymorphism. A major advantage of this proposal is that it is a natural extension of and based upon the PI’s previous highly productive and successful work and outstanding expertise in evolution of the circadian system in prokaryotes.


Project Title: 12th Congress of the European Society for Evolutionary Biology Building-up the Cyanobacterial Circadian Clock: An Evolutionary Perspective
Investigator(s): Dvornyk V
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Evolution of cryptochromes in fish
Investigator(s): Dvornyk V, Sadovy YJ
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
The overall objective of the proposed project is to study evolution of cryptochromes, a family of important circadian genes, in fish and to determine factors having contributed to this evolution. This proposal encompasses the approaches of molecular genetics, genomics, evolut ion, taxonomy, and ecology, and efficiently utilizes PI’s and co-I’s expertise in these fields. The major goals are: 1. Determine patterns of nucleotide and amino acid diversity in the cryptochromes. This will shed light on probable evolutionary forces that shaped this diversity. 2. Reconstruct a comprehensive phylogeny of the genes. 3. Estimate functional divergence between the paralogous members of the cryptochrome gene family. 4. Estimate functional divergence between the orthologous members of the cryptochrome gene family. This will help to identify putative amino acid residues, which are funct ionally important. 5. Determine reliably a timeline of the key events in the genes’ evolution (e.g., gene duplications, etc.). 6. Establish a basis for the future comprehensive evolutionary studies of circadian genes in eukaryotes. To reach the goals, the following specific aims will be fulfilled: 1. Sequence partially eight known fish cryptochromes from 20 fish species representing major taxonomic units and contrasting ecological habitats. 2. Conduct a comprehensive evolutionary analysis of the sequenced genes and to estimate contribution of various evolutionary factors to the observed patterns of nucleotide diversity. A major advantage of this proposal is that it is a natur al extension of and based upon the PI’s previous highly productive and successful work and outstanding expertise in evolution of the circadian system in prokaryotes.


List of Research Outputs

Baca I., Sprockett D. and Dvornyk V. , Circadian input kinases and their homologs in cyanobacteria: Evolutionary constraints versus architectural diversification, Journal of Molecular Evolution . New York, Springer, 2010, 70: 453-465.
Dvornyk V. , Building-up the Cyanobacterial Circadian Clock: An Evolutionary Perspective, 12th Congress of European Society for Evolutionary Biology . Turin, Italy, 2009.
Dvornyk V. , Editorial Board, International Journal on Algae . New York, Begell House, Inc., 2010.
Liu P.Y., Lu Y., Recker R.R., Deng H.W. and Dvornyk V. , ALOX12 gene is associated with the onset of natural menopause in white women, Menopause . LWW, 2010, 17: 152-156.
Liu P.Y., Lu Y., Recker R.R., Deng H.W. and Dvornyk V. , Association analyses suggest multiple interaction effects of the methylenetetrahydrofolate reductase polymorphis ms on timing of menarche and natural menopause in whites, Menopause . LWW, 2010, 17: 185-190.


Researcher : El-Nezamy HS

Project Title: An in vitro model to predict the bioactivity of food ingredients
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 02/2008
Completion Date: 01/2010
Abstract:
Development of future foods is based on detailed knowledge of their biological effects. To gain this knowledge appropriate models that simulate the transpor t and biotransformation of foods and food ingredients in the gastrointestinal tract are needed. Understanding of their metabolism and transport is of critical importance in assessment of both harmful and beneficial effects of these compounds and their interactions with other dietary components. Biotransformation reactions in the liver, intestine and intestinal microbiota differ in that the CYP-mediated oxidative reactions in liver and intestinal cells need oxygen, but most of the intestinal microbes are strictly anaerobic. Consequently, the aim of this project is to develop an in vitro based biochamber model that allows the simultaneous culturing of eukaryotic and prokaryotic cells for studying gastrointe stinal metabolism of food ingredients and their interactions with other dietary components. The key players in the gastrointestinal biotransformations - enterocytes, hepatocytes, colonocytes and intestinal microbiota – are cultured in compartments associated with semi-permeable membranes. To test the feasibility of this chamber, the metabolism of a model compound will be determine d. The model compound to be studied is aflatoxin B1 (AFB1), a liver carcinogen with known metabolic pathways in the body.


Project Title: Combined effects of mycotoxins on the intestinal local immune responses.
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2008
Completion Date: 11/2009
Abstract:
Despite the fact that there are 1000's of original research publications available on the potential toxicity and carcinogenicity of mycotoxins, we have identified several gaps in the literature, particularly in relation to the immunotoxicity of mycotoxins and the proposed project will address a number key issues in this area. Key Issue 1: Interactive effects of mycotoxins. Mycotoxins are a chemically diverse group of compounds. Typically, it is common to detect several types of mycotoxins in the same crop, while it is rare to find a crop which is contaminated with only a single mycotoxin. Data on the immunotoxicity of commonly occurring mixtures of toxins are absent. Key Issue 2: Mycotoxins-induced immunotoxicity on local intestinal immune responses. The intestinal epithelia are the first barrier restricting the entry of foreign antigens and dietary toxins, including mycotoxins, into the underlying tissues. Despite this, the majority of published research on mycotoxins-induced immunotoxicity focuses on their impact on systemic immunity rather than local immunity. Consequently, the specific aim of this pilot project is to evaluate the individual and combined effects of mycotoxins on the intestinal local immune responses, we will study the interactive effects of single, binary and tertiary mixtures of mycotoxins, deoxynivalenol (DON), fumonisin B1 (FB1) and aflatoxin B1 (AFB1), using the human ad enocarcinoma cell line (Caco-2). The end points will include inhibition of cell proliferation and expression of mRNA encoding for pro-inflammatory cytokines (including IL-1β, IL-6 , IL-8, IL-12, IFN-γ and TNF-β). This study will provide useful information on whether these mycotoxins have additive or synergistic immunotoxicity in these epithelial cells.


Project Title: The melamine milk - kidney and developmental toxicity: impact on the foetus and the disease development later in life
Investigator(s): El-Nezamy HS, Chen Y, Tam PKH, Lau ASY, Chen SF, Leung FCC, Lan LCL, Wang M
Department: School of Biological Sciences
Source(s) of Funding: Studies Related to Melamine Incident
Start Date: 04/2009
Abstract:
To evaluate the toxic effects of melamine milk on renal inflammation and kidney stone formation in mice; to evaluate the maternal foetal transplacental passage using ex vivo human placenta model; to investigate in an animal model the short and long term implications of exposure to melamine and its degradation products in utero and during early stages of life.


Project Title: 7th Congress of Toxicology in Developin g Countries Biomarker survey of aflatoxin and deoxynivalenol exposure in pregnant Egyptian women
Investigator(s): El-Nezamy HS
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 09/2009
Completion Date: 09/2009
Abstract:
N/A


List of Research Outputs

El-Nezamy H.S. , Associate Editor, Frontiers in Pharamcology / Frontiers in Predictive Toxicity . 2010.
Gratz S.W., Mykkanen H. and El-Nezamy H.S. , Probiotics And Gut Health : A Special Focus On Liver Disease, World Journal of Gastroenterology . 2010, 16: 403-410.
Partanen H.A. , El-Nezamy H.S. , Leppanen J.M., Woodhouse H.J. and Vahakangas K.H., Aflatoxin B1 Transfer And Metabolism In Human Placenta, Toxicological Sciences . 2010, 113: 216-225.
Salminen S., Nybom S., Meriluoto J., Collado M., Vesterlund S. and El-Nezamy H.S. , Probiotic Pathogen/toxin Interaction - Benefits To Human Health And Nutrition, Current Opinion in Biotechnology . 2010, 21: 157-167.


Researcher : Faan YW

List of Research Outputs

Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.


Researcher : Fan KW

List of Research Outputs

Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Gao W

List of Research Outputs

Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Gao W

List of Research Outputs

Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Gu JD

Project Title: Super genetic engineered bacterium and detoxification enzymes for bioremidiation
Investigator(s): Gu JD
Department: Ecology & Biodiversity
Source(s) of Funding: Matching Fund for Hi-Tech Research and Development Program of China (863 Projects)
Start Date: 02/2004
Abstract:
To study super genetic engineered bacterium and detoxification enzymes for bioremidiation.


Project Title: Uncovering proteins associated with toxin biosynthesis in dinoflagellates by proteomic approaches
Investigator(s): Gu JD, Chan LL
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2007
Abstract:
(1) Identification of“STX-related proteins (SRPs)” by comparing the differential protein expression patterns of phylogenetically closely related toxic and non-toxic strains of A. tamarense by 2-D DIGE under different growth conditions and toxin production; (2) Identification of common “toxic-specific proteins” between phylogenetic ally distant STX-producers in different genera by 2-D DIGE; (3) Characterization of these candidate proteins by trypsin in-gel digestion coupled with matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) by bioinformatic mining for homologues or de novo sequencing by Edman protein sequencing and nanospray tandem mass spectrometry (MS/MS).


Project Title: 110th General Meeting of the American Society for Microbiology Quantitative Detection of Ammonia-oxidizing Archaea (AOA) and Ammonia-oxidizing Bacteria (AOB) in Mangrove Sediment
Investigator(s): Gu JD
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2010
Completion Date: 05/2010
Abstract:
N/A


List of Research Outputs

Han X. and Gu J.D. , Sorption and transformation of toxic metals by microorg anisms, In: R. Mitchell, J.-D. Gu, Environmental Microbiology (2nd ed.) . Hoboken, New Jersey, Wiley-Blackwell, 2010, 153-176.
Hong Y. and Gu J.D. , Bacterial anaerobic respiration and electron transfer relevant to the biotransformation of pollutants, International Biodeterioration & Biodegradation . New York, Elsiver, 2009, 63: 973-980.
Li M. , Hong Y., Klotz M. and Gu J.D. , A comparison of primer sets for detecting 16S rRNA and hydrazine oxidoreductase genes of anaerobic ammonium-oxidizing bacteria in marine sediments, Applied Microbiology and Biotechnology . Heidelberg, Germany, Springer, 2010, 86: 781-790.
Li M. , Yang H. and Gu J.D. , Phylogenetic diversity and axial distribution of microbes in the intestinal tract of the polychaete Neanthes glandicincta, Microbial Ecology . New York, Springer, 2009, 58: 892-902.
Mitchell R. and Gu J.D. , Environmental Microbiology (2nd ed.) . Hoboken, New Jersey, Wiley-Blackwell, 2010, 363.
Yu X. and Gu J.D. , Effect of temperature on removal of iron cyanides from solution by maize plants, Environmental Science and Pollution Research . Berlin / Heidelberg, Springer, 2010, 17: 106-114.
Zhang R. and Gu J.D. , Complete sequence of plasmid pMP1 from the marine environment al Vibrio vulnificus and location of its replication origin, Marine Biotechnology . New York, Springer, 2009, 11: 465-462.
Zhao Z.Y., Gu J.D. , Li H.B., Li X.Y. and Leung K.M.Y. , Disinfection characteristics of the dissolved organic fractions at several stages of a conventional drinking water treatment plant in Southern China, Joural of Hazardous Materials . 2009, 172: 1093-1099.


Researcher : Ho CWJ

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.


Researcher : Ho KY

List of Research Outputs

Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Ho SWT

List of Research Outputs

Ubhayasekera W., Rawat R., Ho S.W.T. , Wiweger M., Von Arnold S., Chye M.L. and Mowbray S., The first crystal structures of a family 19 class IV chitinase: the enzyme from Norway spruce, Plant Molecular Biology . 2009, 71: 277-289.


Researcher : Hon CC

List of Research Outputs

Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Huang W

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.


Researcher : Huang W

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Huang W. , Cai Y. and Zhang Y. , Natural phenolic compounds from medicinal herbs and dietary plants: potential use for cancer prevention, Nutrition and Cancer – An International Journal . 2010, 62(1): 1-20.


Researcher : Hui RKH

Project Title: 2009 Conference of Research Workers in Animal Diseases Effects of Nsp2 Deletions on PRRSV Genome and Replication Efficiency
Investigator(s): Hui RKH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 12/2009
Completion Date: 12/2009
Abstract:
N/A


List of Research Outputs

Hui R.K.H. , Wang K.X. and Leung F.C.C. , Effects Of Nsp2 Deletions On PRRSV Genome And Replic atoin Efficiency., International PRRS Symposium 2009, National Pork Board . 2009.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographi c dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Sympos ium . 2009.


Researcher : Hyde KD

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.


Researcher : Ip KM

List of Research Outputs

Ip K.M. and Wong A.S.T. , p70 S6 kinase regulates the actin cytoskeleton in ovarian cancer cell motility by binding and cross-linking actin filaments, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5116) . 2010.


Researcher : Jiang J

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposi um . 2009.


Researcher : Jiang P

List of Research Outputs

Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Jiang Q

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeti ng of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Jor WY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Jor WY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Karczmarski L

Project Title: Population ecology of Indo-Pacific humpback dolphins. Phase 1: Establishing baseline models and comparative approach
Investigator(s): Karczmarski L
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
Background of Research Indo-Pacific humpback dolphins (Sousa chinensis) occur in coastal waters of Indian and western Pacific oceans, from South Africa in the west to southeast China in the east (Jefferson & Karczmar ski 2001). The population that inhabits the Pearl River Estuary (PRE) has become the focus of international interest due to its proximity to the world’s busiest port and fast developing economy. This dolphin population has been studied since the early 1990’s with a primary focus on estimating abundance, distribution, and conservat ion status (e.g. Jefferson 2000, Jefferson & Hung 2004, Hung & Jefferson 2004). Despite these commendable efforts, this earlier work was restricted almost exclusively on Hong Kong waters and due to methodological limitations did not achieve more in-depth population level analyses. Consequently, much of the population parameters, structure, and socio-ecological dynamics remain poorly known. Genetic studies are very recent and limited, although preliminary data (Chen et al. 2008) suggests low mtDNA diversity; which is surprising in the context of the apparently large population size (believed to be circa 1500 individuals; Jefferson & Hung 2004). This contrad ictions (apparent population size vs. within-population genetic diversity) require further investigations. There has been very little cetacean research elsewhere in the Southeast Asian region and by comparison, despite various limitations, the dolphin population that inhabits PRE is better understood than many other populations of the genus Sousa and all other cetacean populations in Southeast Asia. With the data accumulated over the past years and with recent advances in modern analytical techniques, there is currently a good base and means for examining in greater detail the population ecology and structure, and establishing a broader comparative approach across species and populations in the region. The time is also right for a hypothesis-driven resear ch that would investigate socio-behavioural dynamics of humpback dolphins in a broader context of mammalian behavioural ecology. Objectives This project represents an initial phase of a larger-scale undertaking that is intended for GRF grant support; it addresses a range of topics, from establishing initial quantitative dataset for the 'Primary Objectives' to facilitating 'Broader Comparative Perspective' through collaborative research. To achieve these objectives, the study will go beyond the time-frame of this Seed Funding; all the topics listed below will be explored further under GRF grant application and other funding scheme, but the current project represents a critical first step. Primary Objectives Population Parameters – perform mark-recapture analyses of the humpback dolphin population in the Pearl River estuary; model the population structure, quantify immigration/emigration rates and patterns of geographic fidelity Movement, Ranging Pattern and Individual Range Use – quantify spatial and temporal movement patterns of individuals, including rate of population spread (diffusion) and the displacement of individuals over time Socio-Behavioural Dynamics – quantify groups structure, model individual residence rates and inter- and intra-group social dynamics relative to age and sex, and intra- and inter-sexual relationsh ips within and between groups Genetic Structure and Population Connectivity – quantify and model population genetic structure, assess dispersal pattern, and provide initial basis for broader analysis of population connectivity on a local and regional scale Broader Comparative Perspective Comparative Socio-Ecology – establish a comparative, collaborative research which, with a similar framework of quantitative analytical procedu res, would facilitate constructing a broader model system of a coastal delphinid with the humpback dolphin as a focus species Hypothesis and Analytical Framework A recently proposed socio-ecological model (Gowans et al. 2008) suggests that spatial and temporal predictability of resources, habitat structure, predator pressure, and in some cases availability of mates determine the structure of local populations and their socio-behavioural strategies. According to this model, species inhabiting complex inshore and estuarine systems, where resources are spatially and temporally predictable, are likely to remain resident in relatively small areas. Contrary to wide-ranging large groups of pelagic dolphins, in these diverse inshore environments dolphins can either hide from predators or avoid areas with high predator density. With limited food resources, there are few benefits to forming large groups and potentially many benefits to being solitary or in small groups; while males may be able to sequester solitary females, controlling mating opportunities. However, in open coastal habitat s with variable resources, or in environments substantially altered by human activities, dolphins are likely to display an intermediate-ranging pattern due to less predictable or depleted resources, with some site fidelity over relatively large ranges. At intermediate ranging, dolphins form intermediate-sized groups that are gener ally highly dynamic with little temporal stability, which reduces intra-group scramble competition while still providing protection against predators. This pattern is likely to prevent the formation of long-term complex bonds and might affect male mating strategies. Photographic identification data have shown this model to hold tr ue for humpback dolphins in the coastal environment of South Africa. We suggest that humpback dolphins in the coastal region of the Pearl River Estuary will exhibit similar pattern of dispersal and group formation as humpback dolphins off South Africa (Karczmarski 1999, Karczmarski et al. 1999, 2000, Karczmarski & Guissamulo Under Review) due to comparable environmental pressures. We will test our hypotheses using photographic identification techniques (which will be supported further, in a follow-up study under GRF grant support , by genetic techniques). Through photo-identification mark-recapture analyses, we will examine and quantify the level of geographic fidelity of humpback dolphins using lagged identification rates. We anticipate the dolphins to exhibit weak site fidelity to specific locations within the estuary but a substantially stronger fidelity to the geographic region of the delta. Therefore we predict the lagged identification rates to decrease rapidly in any of the specific survey sites, but be visibly higher and more stable in relation to the entire Pearl River Estuary. The pattern of lagged identification rates and calculated residence rates will facilitate the choice of appropriate population models for further mark-recapture analyses of demographic parameters an d the population size. Using lagged association rates and social network analyses we will quantify temporal stability of associations and community structure. Following the Gowans-Wursig-Karczmarski model (Gowans et al. 2008) we anticipate to find a dynamic fission-fusion society with few (if any) long-term bonds between individu als and great day-to-day lability in group sizes and membership. We also predict to find little or no evidence of genetic structure across the estuary using microsatellite and mtDNA markers due to high levels of dispersal and gene flow across the estuary. Because we predict groups to be composed of random associates, we expect genetic relatedness between individuals within groups to be low, but this will be determined in a follow-up study under GRF support.


List of Research Outputs

Andrews K.R., Karczmarski L. , Au W.W.L., Rickards S.H., Vanderlip C.A., Bowen B.W., Grau E.G. and Toonen R.J., Rolling stones and stable homes: Social structure, habitat diversity, and population genetics of the Hawaiian spinner dolphin (Stenella longirostris). , Molecular Ecology . Wiley-Blackwell, 2010, 19: 732-748.
Karczmarski L. , Dolphinid socio-behavioural variability: Does it matter for conservation ?, International Cetacean Conservation Symposium - Xiamen 2009 .
Karczmarski L. , Habitat driven divergence in population structure and geographic fidelity of humpback dolphins: Implicati ons for conservation , Strategic workshop of the Indo-Pacific Humpback Dolphin Conservation Task Force; Forestry Bureau and Fishery Agency of Council of Agriculture, Taiwan . 2009.
Karczmarski L. and Guissamulo A.T., Humpback dolphins in the south-western Indian Ocean: Habitat driven divergence in population structure and geographic fidelity. Does that matter for conservation ?, Indian Ocean Cetacean Symposium . 2009.
Karczmarski L. , Spinner dolphins off tropical East Africa: Group dyna mics, daily occurrence, and "unusual" pattern of behaviour., Indian Ocean Cetacean Symposium . 2009.
Karczmarski L. , Trials and tribulations of field research: What can we learn from others and our own work? , Workshop on population connectivity and conservation of Sousa chinensis off Chinese coast . 2010.
Reisinger R.R. and Karczmarski L. , Population size estimate of Indo-Pacific bottlenose dolphins in the Algoa Bay region, South Africa., Marine Mammal Science . Wiley-Blackwell, 2010, 26: 86-97.
Zhou K. and Karczmarski L. , Co-organizer and co-chair , Workshop on population connectivity and conservation of Sousa chinensis off Chinese coast . Nanjing, 2010.


Researcher : Karraker NE

Project Title: Importance of Amphibians to Stream Food Webs in Hong Kong
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 08/2007
Abstract:
Amphibians are important components of ecosystems, influencing nutrient fluxes, predator-prey dynamics, and other key ecological functions, and in some regions dominating vertebrate communities (Davic and Welsh 2004). In one study in the northeastern United States, the biomass of terrestrial salamanders was 2.6 times that of birds at the height of the breeding season and equal to that of small mammals (Burton and Likens 1975). In tropical forests of Puerto Rico, terrestrial frogs can attain densities greater than 20,000 per hectare (Stewart and Woolbright 1996). Despite a number of studies on the importance of amphibians to terrestrial ecosystems, their role in aquatic systems has received considerably less study with much of it focused on adults and their biomass relative to that of fish. Indeed, in some headwaters habitats, salamanders, not fish, have been shown to be the dominant vertebrat e predators (Petranka 1983, Lowe and Bolger 2002). In upper reaches of streams, larval amphibians may also replace fish as the dominant vertebrates, yet this relationship has not been well documented, particularly in tropical streams. In addition, the importance of larval amphibians, in terms of biomass, production, and trophic status relative to other stream omnivores has not been defined. In the past few decades, catastrophic declines of some amphibians have been reported from North and South America, Africa, Australia, and Europe, many inexplicably occurring in relatively pristine, well-protected areas, including national parks. In fact, nearly 200 (3%) of 6,000 described species are probably recently extinct, and 30% are considered globally threatened (Stuart et al. 2004, IUCN, Conservation International, and NatureServe 2006). Declines in amphibian populations have been associated with habitat destruction, pollution, invasive species, climate change, and disease. In particular, dramatic declines in Australia and Latin America have been associated with chytridiomycosis (Berger et al. 1998, Lips et al. 2006), an extremely pathogenic disease caused by the fungus Batrachochytrium dendrobatidis and reported in amphibians from all continents except Asia. As amphibian declines and extinctions are occurring at unprecedented rates, and still without consensus among the scientific community as to their causes in several regions (e.g. Pounds et al. 2006, Mendelson et al. 2006), it has become imperative to understand the ecological roles played by these organisms in regions where populations remain intact in order to determine how ecosystems may be impacted in the event of future declines. While production and trophic structure of tropical stream communities are increasingly being studied (e.g. Flecker 1992, Rosemond et al. 2001 , March and Pringle 2003), with extensive research occurring in Hong Kong (e.g. Salas and Dudgeon 2003, Mantel and Dudgeon 2004, Yam and Dudgeon 2005), this research has rarely included amphibians. In perhaps the first such study (Ranvestal et al. 2004), tadpoles exerted strong influences on both primary production and primary consumers. Tadpoles altered the biomass of algae, and mayfly abundances increased in the presence of tadpoles due to their removal of sediments from grazi ng surfaces. In a comparison of two streams in Panama, one with tadpoles and one in which tadpoles had been extirpated, tadpoles influenced the quantity and quality of suspended sediments and recycling of nitrogen, and these and other factors were probably responsible for a truncated food web in the stream without tadpoles (Whiles et al. 2006). Given that this latter study occurred following a recent and ongoing amphibian decline in the region, it reinforces the need for an increased understanding of the ecological importance of amphibians to aquatic ecosystems. In light of declining amphibian populations, a call has been made (Petranka and Kennedy 1999, Altig et al. 2007) to define the trophic relati onships of amphibians in their ecosystems, so as to better understand the potential ecological consequences of declines. The overarching goal of our research is to delineate the importance of amphibians to Hong Kong’s streams relative to other stream organisms and to understand the trophic status of amphibians within stream commun ities. In addition, we plan to assess the health of amphibian populations in Hong Kong. The specific objectives of this research are to characterize: (1) density, biomass, and production of Xenophrys brachykolos and Paa exilispinosa tadpoles within habitats relative to that of shrimps, snails, and aquatic insects; (2) describe the trophic relationships of X. brachykolos and P. exilispinosa relative to other consumers in the stream using stable isotope analysis; (3) and survey populations of X. brachykolos and P. exilispinosa for the fungal disease, chytridiomycosis. *References available upon request.


Project Title: Population Dynamics of Amphibians in Land-water Ecotones
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Completion Date: 08/2010
Abstract:
Amphibians are key components of ecosystems, influencing predator-prey dynamics, nutrient fluxes, and other important ecological functions, and in some regions dominating vertebrate communities (Burton and Likens 1975; Davic and Welsh 2004). In particular, anurans (frogs and toads) are considered to be one of the most important vertebrate group in terms of abundance and diversity in the tropics. In tropical forests of Panama, riparian frogs occurred at densities up to 1.35 sq m in Panama (Lips et al. 2003) and terrestrial frogs can achieve densities greater than 2.48 sq m in Puerto Rico (Stewart and Woolbright 1996). Despite a number of studies on the importance of amphibians to terrestrial ecosystems, their role in aquatic systems has received considerably less study. One study of stream frogs in Panama reported densities of 0.36 adult anurans per linear m of stre am (Ranvestal et al. 2004), yet information on adult anuran densities is limited for other regions of the tropics. Beginning in the 1980s, significant declines of amphibians have been reported from North and South America, Africa, Australia, and Europe, with many unexplained declines occurring in relatively undisturbed, well-protected areas, including national parks. In fact, nearly 200 (3%) of 6,000 described species are probably recently extinct, and 30% are considered globally threatened (IUCN 2006; Stuart et al. 2004). As these declines and extinctions are occurring at unprecedented rates, and still without consensus among the scientific community as to their causes (Mendelson et al. 2006; Pounds et al. 2006), it has become imperative to document the baseline ecology, population estimates, and densities of these organisms in regions where populations remain intact in order to be able to detect population declines if they begin to occur. Despite a long history of naturalists exploring the forests and streams of Hong Kong, the ecology of the 23 locally extant species of amphibians remains virtually unknown. While many of Hong Kong’s species also occur in Guangdong Province and a few are more broadly distributed throughout Southeast Asia, their ecology in these other regions is also poorly documented. The earliest studies (e.g. Boring 1934; e.g. Romer 1951) described the taxonomy of the region’s amphibians and reported natural history observations. The first comprehensive study of the distributions and habitat use of Hong Kong’s amphibians (Lau 1998) was conducted in the mid 1990s, but only the distribution data were published (Lau and Dudgeon 1999). Ongoing surveys are conducted each summer by the Hong Kong Government’s Agriculture, Fisheries, and Conservation Department, but such surveys only document presence of species and not abundances. Any conservation program for amphibian species must be developed based upon an understanding of ecology and demographic traits, yet were the need arise to develop such a program in Hong Kong our existing knowledge of these factors would be woefully inadequate. At a recent workshop in Hong Kong, scientists from Hong Kong and Guangdong Province met to prioritize amphibian species for conservation efforts in the region. Of 66 species evaluated, three species abundant in Hong Kong’s streams, the lesser spiny frog (Paa exilispinosa), the short-legged toad (Xenophrys brachykolos), and the green cascade frog (Rana chloronota) ranked in the top 15 in terms of conservation priority. For each of these species, it was determined that conservation plans could not be developed until baseline information on the ecology and population biology of these species was gathered. Such information would be needed for the initiation of ex situ conservation measures in the event that declines occur and such measures become necessary in the future. As part of another study, we have determined that tadpole densities and biomass in Hong Kong streams are higher than those reported from other regions of the world, and pilot surveys for adults have suggested that adult densities may also be exceptionally high. Because amphibians use terrestrial and aquatic ecosyste ms at different stages of their life cycles, high densities and biomass of amphibians may have important implications for the functioning of these systems, in terms of roles as predator and prey, nutrient fluxes, and food web dynamics. The specific objectives of this study are to characterize the population biology and densities of adult stream amphibians in Hong Kong by quantifyi ng (1) population sizes and densities, (2) movements, (3) age structure, and (4) diet. This proposed research will represent, to our knowledge, the first ecological study of the adults of several stream-breeding amphibian species and will shed light on their importance to Asian stream ecosystems. *References can be provided upon request.


Project Title: 2009 Joint Meeting of Ichthyologists and Herpetologists Importance of tadpoles to stream communities in tropical Asia
Investigator(s): Karraker NE
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Evaluating Amphibian Population Declines and Environmental Change in Hong Kong
Investigator(s): Karraker NE, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2009
Abstract:
1) Resurvey 165 sites to determine if they sustain the same or different species assemblages; 2) Identify changes in land cover and habitat degradation in and around these sites between 1996 and 2010; 3) Identify probable causes and ongoing threats to the persistence of species that have experienced population extirpations; 4) Develop a habitat restoration and reintroduction plan for the rough-skinned floating frog.


List of Research Outputs

Karraker N.E. , Associate Editor, Journal of Herpetology . 2010.
Karraker N.E. , Arrigoni JR J.E. and Dudgeon D. , Effects of increased salinity and an introduced predator on lowland amphibians in Southern China: Species identity matters, Biological Conservation . 2010, 143: 1079-1086.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Annual Meeting of the Society for Conservation Biology . 2009.
Karraker N.E. and Dudgeon D. , Importance of Tadpoles to Stream Communities in Tropical Asia, Joint Annual Meeting of Ichthyologists and Herpetologists . 2009.


Researcher : Ko KW

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.


Researcher : Kong KF

List of Research Outputs

Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.


Researcher : Koutsaftis A

List of Research Outputs

Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Kuang R

List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.


Researcher : Kwok HYA

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y., Li J., Kwok H.Y.A. , Ge W. and Leung F.C.C. , A novel prolactin-like protein (PRL-L) gene in chickens and zebrafish: cloning and characterization of its tissue expression, General and Comparative Endocrinology . 2009, 166: 200-210.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Kwok KPWH

List of Research Outputs

Rhodes J.R., Grist E.P.M., Kwok K.P.W.H. and Leung K.M.Y. , A Bayesian mixture model for estimating intergeneration chronic toxicity, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong L.C., Kwok K.P.W.H. , Leung K.M.Y. and Wong C.K., Relative sensitivity distribution of freshwater planktonic crustaceans to trace metals, Human and Ecological Risk Assessment . 2009, 15: 1335-1345.


Researcher : Kwok WHKP

List of Research Outputs

Kwok W.H.K.P. and Leung K.M.Y. , Marine Pollution Bulletin Highly Cited Author Award 2005-2009, Marine Pollution Bulletin, Elsevier . 2010.


Researcher : Lam CW

List of Research Outputs

Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Lam PY

List of Research Outputs

Lam P.Y. , Glasser G., Gaudio E., Chow B.K.C. , Onori P., Franchitto A., Carpino G., Venter J., Francis H., Mancinelli R., Kopriva S. and Alpini G., Knock out of secretin receptors reduces large cholangiocyte hyperplasia in mice with extrahepatic cholestasis induced by bile duct ligation., Hepatology . 2010, 52: 204-214.


Researcher : Lam TY

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Repr oductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symp osium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Lia ng H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Lam TY

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproducti ve and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zhen g H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the ori gin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Lau CP

List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecologica l effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Lau CY

Project Title: Comparative aerobiology in outdoor environments in Hong Kong
Investigator(s): Lau CY, Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2008
Completion Date: 04/2010
Abstract:
Purpose of the project To compare the total microbial populations in the aerosphere of urban, sub-urban and rural areas in Hong Kong over a temporal scale of one year, identify community-shaping factor(s) by encompassing the changing meteorological factors and pollution conditi ons and assess the degree of necessity of including bio-aerosol data in air pollution assessment Key issues and problems being addressed Aerobiology is defined by Spieksma (1991) as ‘the study of organic particles, such as bacteria, fungal spores, very small insects and pollen, which are passively transported by the air’. Natural Resources Institutes (UK) (http://www.nri.org/) describes it as ‘the study of the movement and dispersal of living or once-living materials through the atmosphere’. Here aerobiology is interpreted as the general study of microbial lives (at any stages of their life cycles) and biologically-originated organic substances such as pollens that are associated within the aerosphere. Quality of air has long been proposed and studied for their potential risks to public health in the regards to the contemporary seriousness of air pollution. The adverse effects caused by abiotic elements in the air are comparatively broadly realized by the general public, than that caused by the biological counterpart (except air-transmitting diseases). For instance, respiratory symptoms resulted from allergy to airborne chemicals (Elberling et al. 2005) and deteriorated functioning of respiratory and cardiovascular systems and the possible fatality due to elevated levels of particulates (Mohanraj & Azeez 2004; World Health Organization 2005). Causal agents for infectious air-transmitting diseases form an evitable part of the aerobiology. Viral diseases, such as smallpox, measles, mumps, avian influenza (H5N1) (Tellier 2006) and severe acute respiratory syndrome (SARS) (Yu et al. 2004 for original article and correspondenc e) are carried passively by inorganic and organic particles (or droplets) that are present in the atmosphere. Taken the lesson from the outbreak of H5N1 and SARS, the pandemic potential of emerging infectious diseases should not be overlooked (Blachere et al. 2007). Awareness to viral taxa existing in the air is therefore urged in order to enhance our predictability over the epide mic of air-borne diseases caused by virus, to establish proper monitoring strategy (before, during and after the peak seasons for certain virus) and ultimately to prevent the panicking situation of widespread transmission. Air quality in Hong Kong is reflected via the means of an air pollution index system (or the API), which is responsible by the governmental unit, Environmental Protection Department. The API is a conversion value (in the scale of 0 to 500) based on the concentrations of 5 types of major chemicals measured on an hourly-basis at fourteen fixed monitoring stations (http://www.epd.gov.hk/ epd/). Similar monitoring systems are also in application in other countries elsewhere, namely Australia, Canada, Finland, Korea, Mexico, the Philippines, Singapore, Taiwan and the USA (http://www.epd.gov.hk/epd/). Nonetheless, studies found that comparable health problems could be induced or worsened by contacting airborne biolog ical sources, such as pollens (Newton et al. 1997), fungal spores (Bush & Portnoy 2001), moulds and mites (Zureik et al. 2002) and others (reviewed by Griffin 2007). As a result, to us, the inclusion of both abiotic and biotic parameters is going to provide a more comprehensiv e reflection on the air quality and therefore a better reference for planning our daily activities and taking essential measures if needed. Reference: Blachere, F.M., W.G. Lindsley, J.E. Slaven, B.J. Green, S.E. Anderson, B.T. Chen and D.H. Beezhold (2007) Bioaerosol sampling for the detection of aerosolized influenza virus. Influenza and Other Respiratory Viruses 1: 113-120 Bush, R.K. and J.M. Portnoy (2001) The role and abatement of fungal allergens in allergic diseases. J Journal of Allergy and Clinical Immunology 107: 430-440 Calderon, C., E. Ward, J. Freeman and A. McCartney (2002) Detection of airborne fungal spores sampled by rotating-arm and hirst-type spore traps using polymerase chain reaction assays. Aerosol Science 33: 283-296 Elberling, J., A. Linneberg, H. Mosbech, A. Dirksen, T. Menné, N.H. Nielsen, F. Madsen, L. Frolund and J. Duus Johansen (2005) Airborne chemicals cause respiratory symptoms in individuals with contact allergy. Contact Dermatitis 52: 65-72 Griffin, D.W. (2007) Atmospheric movement of microorganisms in clouds of desert dust and implications for human health. Clinical Microbiology Reviews 20: 459-477 Hernandez, M., S.L. Miller, D.W. Landfear and J.M. Macher (1999) A combined flurorochrome method for quantitation of metabolically active and inactive airborne bacteria. Aerosol Science and Technology 30: 145-160 Mohanraj, R. and P.A. Azeez (2004) Health effects of airborne articulate matter and the Indian scenario. Current Science 87: 741-748 Newson, R., K. Strachan, E. Archibald, J. Emberlin, P. Hardaker and C. Collier (1997) Effect of thunderstorms and airborne grass pollen on the incidence of acute asthma in Englan d, 1990-1994. Thorax 52: 680-685 Tellier, R. (2006) Review of aerosol transmission of influenza A virus. Emerg Infect Dis 12: 1657-1662 World Health Organization (2005) Particulate matter air pollution: how it harms health. Fact sheet EURO/04/05 Yu, I.T.S., Y. Li, T.W. Wong, W. Tam, A.T. Chan, J.H.W. Lee, D.Y.C. Leung and T. Ho (2004) Evidence of airborne transmission of the severe acute respiratory syndrome virus. The New Engl and Journal of Medicine 350: 1731-1739 [original article] Yu, I.T.S., Y. Li, T.W. Wong, W. Tam, A.T. Chan, J.H.W. Lee, D.Y.C. Leung and T. Ho (2004) Evidence of airborne transmission of the severe acute respiratory syndrome virus. The New England Journal of Medicine 351: 609-611 [correspondence] Zureik, M., C. Neukirch, B. Leynaert, R. Liard, J. Bousquet, F. Neukirch (2002) Sensitisation to airborne moulds and severity of asthma: cross sectional study from European Community respiratory health survey. BMJ 325: 411


List of Research Outputs

Lau C.Y. , Fund for world practical courses 'Bioinformatics and Comparative Genome Analysis', EMBO - Institut Pasteur Paris . 2009.
Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.


Researcher : Lee PP

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.


Researcher : Lee TO

Project Title: Transcriptional regulation of a nasopharyngeal carcinoma tumor suppressor: RASSF1A
Investigator(s): Lee TO, Chow BKC
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To elucidate the basal transcription regulation mechanisms of RASSFIA in normal - RASSF1A -expressing and RASSF1A -non-expressing NPC cells; to fine map the core promoter region of RASSF1 gene; identify transcription factor(s) that regulates RASSF1A expression.


Project Title: Molecular evolution of PACAP and VIP receptors in agnathan: Searching for the ancestr al PACAP/VIP receptor gene of vertebrates.
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 04/2010
Abstract:
To identify PACAP/VIP rece Background: Evolution of G protein-coupled receptors GPCRs Recently, the availability of genomic sequences from various genome projects has provided us with the opportunity to loc ate conserved sequence motifs that are responsible for specific functions via comparative approaches. This idea is applicable to investigating GPCRs, the biggest gene family in the animal kingdom. Using these data, the evolutionary origin of existing GPCRs, signaling pathway, ligand-receptor interactions, and other functionally relevant elements can be studied. GPCRs are crucial to a diversity of physiological functions by mediating extracellular signals and leading to cellular responses. The superfamily can be classified according to the GRAFS system, including: Glutamate, Rhodopsin, Adhesion, Frizzled and Secretin receptors [1]. The occurrence of GPCRs, as well as G-protein signaling pathways, could date back to ~1.2 billion years, from a common ancestor before plants, fungi and animals emerged. To-date, the phylogenetically “oldest” GPCRs that have been studied are fungal pheromone, cAMP-receptor-lik e and glutamate-receptor-like receptors [2]. Among these GPCRs, the rhodposin receptor family is the most studied. It was proposed that the first rhodopsin-like receptors appeared around 580-800 million years ago (MYA) in several protostome Bilateria, such as insects and nematodes . Afterwards, the number of GPCRs increased during evolution and the vertebrate GPCR numbers doubled comparing to invertebrates [3]. In other sub-families, especially the secretin-like receptors, their structure and evolution are not well characterized. PACAP, VIP and their receptors Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) are prominent neuropeptides that are structurally related [4]. They belong to the secretin/PACAP/VIP peptide family based on sequence identity. PACAP and VIP are widely distributed in the central nervous system and peripheral tissues. They have been found to exert many physiological and pathophysiological effects in development, growth, immune response, circadian rhythm, digestion, respiration, reproduction and heart functions. The actions of PACAP are mediated through the activation of specific receptors. There are three VIP/PACAP receptors in mammals: PAC1R, VPAC1R, and VPAC2R [6]. All these receptors are members of the secretin receptor family. The secretin receptor family can further be sub-divided into five branches via their interactions with the following peptides: a) Corticotrophin Releasing Factor (CRF); b) Secretin, VIP, PACAP, Growth Hormone-Releasing Hormone (GHRH) and recently characterized non-mammalian PACAP-related peptide (PRP); c) Glucagon, Glucagon-Like Peptides (GLP-1 or GLP-2), Glucose Insulinotropic Pept ide (GIP); d) Parathyroid Hormone (PTH). e) Calcitonin and Calcitonin Gene-Related Peptide (CGRP). Members in these subfamilies share high degree of amino acid sequence similarity within the seven transmembrane domains. The receptors in the secretin family have rather long N-termini, often between 60 and 80 amino acids, with conserved disulfide bridges [5]. The evolution of PACAP, GHRH and VIP genes was previously proposed in accordance to their structures and genomic organizations [7]. It was hypothesized that the mammalia n GHRHs were evolved from non-mammalian GHRH-like peptides which are encoded in the same gene with PACAP. Our recent study, however, provided new information regarding the evolution of PACAP, GHRH and VIP in non-mammalian vertebrates [8]. We convincingly showed that `a “real” GHRH, capable of stimulating growth hormone release, is distinctly present in another precursor protein, and hence in another gene, as in mammalian species. The so-called GHRH-like peptides are in fact PACAP-related peptides (PRPs). This conceptual revolution of the identities of GHRH and PRP in non-mammalian vertebrates sways the plausibility of the model previously proposed. For PACAP/VIP receptors, VPAC2R and PAC1R are located on the same chromosome in human and rat (human chromosome 7 and rat chromosome 4), whereas VPAC1R is located on human chromosome 3 and rat chromosome 8. Therefore, it was suggested that the evolution of PACAP/VIP receptors involved two rounds of gene duplication. In the first duplication, VPAC1R gene produced the common ancestor for VPAC2R/PAC1R, and in the second duplication, the ancestral gene of VPAC2R/PAC1R produced VPAC2R and PAC1R [9]. However, mapping of receptors in the chicken genome does not support this hypothesis. In the chicken genome, all PACAP/VIP receptors are located in chromosome 2, and PAC1R and VPAC1R are separated by our newly discovered PRPR gene. It is therefore possible that PAC1R is produced from duplicating VPAC1R directly. Meanwhile, as translocation of PACAP/VIP receptors are observed in some teleost models (zebrafish and fugu), information obtained from teleost is not suitable for investigating the evolution of PACAP/VIP receptors. Consequently, without information of PACAP/VIP receptors from lower vertebrates, especially from Agnathans, evolution of PACAP/VIP receptors remains to be established. Our Hypothesis: PACAP/VIP receptors are evolved from a common ancestor between tunicates and agnathans PACAP, VIP and their receptors are rarely studied in agnathans and invertebrates. The only published record is the identification of 2 PRP/PACAP genes in tunicate (Chelyosoma productum). It was thought that PACAP and their recept ors are emerged at/before protochordate. A cephalochordate genome, amphioxus (Branchiostoma floridae) provided additional information to the story. Amphioxus is a cephalochordate that is regarded as one of the closest living relative of vertebrates. Amphioxus shares several structural features with vertebrates like a dorsal, hollow notochord, segmental muscles and pharyngeal gill slits. Amphioxus genome was recently released by Joint Genome Institute. From the genomic data, CRF, PTH and calcitonin secretin-like receptor are found in amphioxus [10]. No receptors from the PACAP/VIP/secretin receptor subgroup could be identified in amphioxus genome. Also, by bioinformatic analysis, no member of PACAP/VIP peptide family is found in amphioxus. As it has been recently been suggested that tunicates could be more closely related to vertebrates than cephalochord ates based on phylogenetic analysis [11]. The missing PACAP/VIP receptors and ligands suggest strongly that the PACAP/VIP ligand-receptor were emerged after the separation of cephalochordates from tunicates and/or vertebrates. More important, genes encoding PACAP and VIP are predi cted from the sea lamprey genome by our preliminary data. Together with our recently identified VIP-like receptor in hagfish (Figure 1). We hypothesize that PACAP/VIP and their receptors are emerged from a common ancestor in the time between tunicates and agnathans evolution. Objectives: 1. ptors in lamprey and hagfish 2. To functional characterize these PACAP/VIP receptors 3. To propose a hypothesis showing the origin and evolution of PACAP/VIP receptor family.


Project Title: A role of secretin in the subfornical organ in sensing osmotic changes
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To investigate the role of secretin in SFO in regulating water intake; (2) To study the regulation of secretin gene in SFO under osmotic changes; (3) To substantiate the hypothesis that secretin is a part of the upstream pathway in SFO in Ang II-mediated control of volume homeostasis.


Project Title: Interactions of secretin and orexin in controlling food intake
Investigator(s): Lee TO, Chow BKC, Sun H
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Abstract:
Appetite is regulated by a complex system of centr al and peripheral signals which interact to modulate the individual response to nutrient ingestion. During a meal, satiety signals originated from the gastrointestinal tract reach the nucleus tractus solitaries (NTS) through the vagus nerve.The NTS then projects the signal to the arcuate nucleus (ARC) where these peripheral signal s are integrated with the central signals to control behavioral responses to a meal via downstream brain areas [1-3]. Lateral hypothalamuic area (LHA) is one of the brain areas controlled by ARC and is refereed as a feeding center in brain. Bilateral lesions in the LHA result in anorexia (lack of appetite) and animals may die of starvation after the lesions. It has been postulated that when body weight decreases or when the ARC senses “hunger”, LHA is activated to increase food intake. One of the mechanisms in LHA to increase appetite is to secret the orexigenic peptide, orexin. Two orexin peptides, orexin-A and orexin-B, are produced from a common prepro-orexin precursor [4, 5]. Orexin-A is a 33-residue peptide with two intrachain disulfide bonds, while orexin-B is a linear 28-residues peptide. Both peptides bind to two G protein-coupled receptors, orexin-1 (OX1R) and orexin-2 (OX2R) receptor. In vitro analysis showed that OX1R selectivity interacts with orexin-A while OX2R is able to interact with both orexins [6]. There are numerous studies suggesting that orexins could increase appetite. During fasting, the plasma orexin-A level and transcript level of prepro-orexin in LHA were increased significantly [4]. In passive immunoneutralization studies, infusion of antibodies of orexin-A reduced feeding in response to an overnight fast [7]. Moreover, the food intake induced by exogenously injection of orexin or fasting is decreased by anOX1R antagonist SB-334867 [8]. Orexin knockout mice (prepro-orexin gene deletion) ate less than wild-type mice, also sugge sting a physiologically role for endogenous orexin in the regulation of appetite [9]. However, it is interesting to note that the orexin knockout mice grew normally. This observation indicating that some other determinant of food intake/body growth may be involved to compensate the lost of the orexin pathways [9]. On the basis of their hypothalamic localization and their sequence similarity to secretin, orexin is also named as hypocretins. In the alignment (Fig.1), orexin shares an identical region with the C-terminus of secretin. Also, additional sequence identities can be found between N-terminal residues of secretin and C-terminal residues of orexins. Therefore, it has been suggested that orexin was evolved from secretin by circular permutation. The structural similarity between orexin and secretin suggested the possible interaction between secretin, orexin and their receptors. However, secretin did not show significant binding to orexin receptors or stimulate cellular response in CHO cells expressing human OX1R or OX2R [10]. In receptor binding studies using rat hypothalamus, secretin was able to displace [125I]orexin-A significantly [11, 12]. Recently, we have shown that secretin receptor (SCTR) is also expressed in hypothalamus [13, 14], therefore, it is possible that secretin and orexin-A in hypothalamus are competing for SCTRs but not orexin receptors. The potential role of secretin in appetite control was also suggested in our studies. By intrace rebroventricular (icv) injection of secretin into the lateral ventricle (LV), a significantly suppressed 24-hours food intake (Fig.2) was observed in both rats and wild-type (SCTR +/+) mice but not in SCTR knockout (SCTR-/-) mice. During fasting, the expression of both secretin and its receptor transcripts are decreased in rat hypothalamus (Fig.3). We have also shown the expressions of secretin and SCTR in LHA (Fig.4). These data indicated that secretin possesses an anorectic effect in rodents and this act ion may be involved the LHA. During fasting, the expression of orexin in LHA was increased while secretin expression was decreased. We propose here that the increased orexin not only stimulates the well known orexinergic pathways to enhance food intake, it may also inhibit the anorectic effect of secretin by competing with secretin on SCTR. To substantiate this hypothesis, we proposed to study the following: 1. To investigate interactions and signaling pathways of orexin and secretin with their receptors 2. To study structures responsible for ligand-receptor binding for orexin and secretin with their receptors 3. To evaluate the role of orexin in appetite control in SCTR knockout mice.


Project Title: The 9th International Symposium on VIP, PACAP and Related Peptides Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates
Investigator(s): Lee TO
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 10/2009
Completion Date: 10/2009
Abstract:
N/A


Project Title: Implications of PACAP/VIP receptor gene duplications in early vertebrates
Investigator(s): Lee TO, Chow BKC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To consolidate a revised evolutionary scheme for PACAP/GHRH/SCT receptors by characterizing these receptors in several animal models that are crucial to the understanding of early vertebrate evolution; 2) To investigate if PACAP/VIP receptors were evolved from a common ancestral gene after the separation of vertebrate lineage from cephalochordate/urochordate; 3) To substantiate that PHIR shares the same origin with VPAC2R, and it was evolved only after the teleost- specific genome duplication event; 4) To characterize fish SCTR and to search for SCTR in early vertebrates.


Project Title: The role of glucagon receptor family in the unique hyperglycermic activity of teleosts glucagon-l ike peptide 1.
Investigator(s): Lee TO
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
Glucagon and the glucagon-like peptides 1 (GLP-1) are paramount regulators of carbohydrate, fat and protein metabolism, as well as blood glucose level. They are encoded by the proglucagon gene together with glucagon-like peptides 2 (GLP-2). Even though the structures of these peptides are highly comparable, in mammals, the functions of glucagon and GLP-1 oppose to each other in blood glucose regulation. In mammals, glucagon is produced and secreted by the pancreatic α cells in response to low blood glucose levels and it serves as the major counter-regulatory hormone to insulin(1). Among vertebrate s, the major physiological functions of glucagon appear to be conserved. Both fish and mammalian glucagons elevate blood glucose level via inducing hepatic glycogenolysis and gluconeogeneisis(2-3). While the regulatory function of glucagon on insulin has been maintained from fish to mammals, GLP-1 has changed its physiological function. In mammals, GLP-1 is an incretin hormone that stimulates insulin secretion from pancreatic β cells. In disparity, fish GLP-1, produced in both pancreas and intestine, shows a glucagon-like activity contrasting the insulin-l ike activity of mammalian GLP-1(4-5). Bowfin fish (Amia calva) GLP-1 fails to stimulate insulin release from pancreas and it was found to be hyperglycermic and glucagon-like(6-7). Fish GLP-1 accelerates glucose transport and curtails glucose oxidation in enterocytes and it was found to elicit an increase in cAMP level in brain and enterocytes. GLP-1 also acts directly on the liver by supplementing the action of glucagon, including glycogenolysis, gluconeogenesis and lipolysis, but no such increase in cAMP level is noted in isolate d hepatocytes in vitro(8). Therefore, GLP-1 is found to have acquired and subsequently lost gluconeogenic activity during the evolution as illustrated by its contrasting functions in fish and mammals. This leads to possibility of either the peptide or receptor being responsible. In the case of the proglucagon-derived peptides, the high conservation of primary structure indicates strong evolutionary pressure to preserve function. Hence, the receptor may play a greater contributing factor as to why there was a change in biological activity. To elicit their biological functions, glucagon and GLPs interact with corresponding receptors: glucagon receptor (Glu-R), GLP-1 receptor (GLP-1R) and GLP-2 receptor (GLP-2R). Collectively, these receptors belong to a class II B superfamily of G protein-coupled receptor s family. To date, although a range of proglucagon ligand and receptor sequences are known, most research has been focused on mammals and the information regarding receptors in fish and frogs is relatively sparse. In fish, the goldfish (Carassius auratus) and zebrafish (Danio rerio) are the only species in which molecular cloning of glucagon and/or GLP-1 receptors has been successfully achieved(4, 9), whilst fugu (Takifugu rubripes), pufferfish (Tetraodon nigroviridis) and medaka (Oryzias latipes) comprise of the remaining species where receptor sequences have been predicted by data mining of their respective genomes. It was previously hypothesized that as a result of the fish-sp ecific gene duplication event early in teleost evolution prior to species diversification, a duplicate Glu-R acquired GLP-1 binding ability whilst retaining glucagon binding ability, thus giving rise to receptors currently recogni zed as “fish GLP-1Rs” and are paralogous to Glu-Rs. The original GLP-1R in fish was also thought to have been lost from the fish lineage(10). However by extensive data mining of the fugu, pufferfish and medaka genomes, we have been able to predict sequences resembling those of known GLP-1Rs, forming a separate GLP-1R group. In our phylogenetic analysis, with the exception of fish GLP-1R-likes, all glucagon superfamily receptors can be grouped based on subtype. The results indicate fish GLP-1R-likes to be closely related to fish Glu-Rs and are clustered together within the Glu-R group. This suggests that a “true” GLP-1R in fish does indeed exist and was not lost. Based on this finding, we believe previously identified “fish GLP-1Rs” should be termed as “fish GLP-1R-likes”. Non-fish vertebrates have true GLP-1Rs exhibiting high resemblance in both phylogenet ic analysis and physiological function. Therefore, this may suggest that the true fish GLP-1R is non-functional or functionally different to mammalian counterparts, thus resulting in GLP-1’s unique glucagon-like activity in fish. To substantiate this hypothesis, we proposed to study the following: 1. Isolate and express the Glu-R, GLP-1R, and GLP-1R-like receptors in three teleo st animal models: goldfish (Carassius auratus), pufferfish (Tetraodon nigroviridis) and zebrafish (Danio rerio), 2. Evaluate the ligand-specificity and signaling properties of the identified teleost glucagon and GLP-1 receptors, 3. Study the role of the conserved motifs of the receptors by mutagenenesis-based strategy.


List of Research Outputs

Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin : a neurosecretory factor regulating body water homeostasis, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.
Chu J.Y.S. , Lee T.O. , Lai C.H. , Vaudry H., Chan Y.S. , Yung W.H. and Chow B.K.C. , Secretin as a neurohypophysial factor regulating body water homeostasis, Proceedings of National Academy of Sciences,USA . 2009, 106: 15961-15966.
Chu J.Y.S. , Lee T.O. , Chan Y.S. and Chow B.K.C. , Secretin: A neurosecretory factor regulating body water homeostasis, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.
Lee T.O. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, The 9th International Symposium on VIP, PACAP and Related Peptides . 2009.
Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.


Researcher : Lee WWM

Project Title: Interaction and ultrastructure of cell junction proteins in the testis
Investigator(s): Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2006
Completion Date: 08/2009
Abstract:
(1) What are the functional and structural relati onship between tight junctions and basal ectoplasmic specialization (ES) structural protein complexes at the blood-testis barrier (BTB) ? Are there any common adaptors that structurally and functionally link the cadherin/catenin/c -Src/MTMR2, the nectin/afadin/ponsin, and the TJ protein complexes together to regulate BTB dynamics? (2) What are the molecular composition of the laminin α(?)β(?)γ3 receptors and its associated peripheral proteins, which interac t with α6β1 integrin at the apical ES?


Project Title: Extracellular matrix proteins and cell junction dynamics in the testis.
Investigator(s): Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Abstract:
To investigate the role of collagens and collagen fragments in BTB junction dynamics. Can fragments of collagen IV perturb Sertoli cell functions, such as Sertoli cell tight junction-barrier, MMP-9 and TIMP-1 productions? To investigate the role of proteases and protease inhibitors in BTB junction dynamics. Can a disruption of the protease and protease inhibitor homeostasis modulate cytokine-induced transient BTB damage in the seminiferous epithelium?


Project Title: Paracrine regulations of blood-testis barrier dynamics
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2009
Completion Date: 12/2009
Abstract:
The blood-testis barrier (BTB) is formed by cell junctions between adjacent Sertoli cells in the testis. It is important for several reasons. First, it creates a microenvironment for germ cell development. Second, it insulates meiotic germ cells from the systemic cir culation, thereby protecting them from potential cytotoxic substances and autoimmune recognition, and confers apical-basal polarity. Third, it must open and close at time interva ls to allow the passage of preleptotene spermatocytes from the basal to adluminal compartment. Fourth, the delivery of drugs or contraceptives must take into account the constraints imposed by the BTB [1]. In this proposal, the P.I. seeks to examine how cytokines (e.g., tumor necrosis factor-a, TNF-a and transforming growth factor-b3, TGF-b3) are working in coordination with testosterone to regulate the BTB dynamics in adult rat testes. This allows the germ cells to traverse across the BTB, while at the same time still maintaining the barrier integrity. Recent studies from the P.I.’s laboratory have shown that TNFa and TGF-b3 disrupt the Sertoli cell tight junction (TJ)-permeability barrier in vitro and the BTB integrity in vivo [2] (for reviews, see [3]). It is plausible that cytokines (e.g., TNFa)secreted by Sertoli and germ cells into the BTB microenvironment induce the “opening” of the BTB to facilitate preleptotene spermatocyte migration that occurs at stages VII-VIII of the epithelial cycle. Along the line, it has also been shown that testosterone promotes the BTB integrity based on studies using the Sertoli cell specific androgen receptor knockout (SCAR KO) mouse model. For instance, SCAR KO mice are infertile due to spermatogenic arrest before the first meiosis [4] and the BTB in these mice was shown to be impaired plausibly as the result of reduced integral membrane proteins at the BTB. This promoting effect of testosterone on the BTB in vivo is also consistent with earlier in vitro studies that androgen promotes the Sertoli cell TJ-barrier and cell adhesion [5]. Furthermore, the expression of androgen receptor in adult testes is also stage-specific, being highest at stages VII-VIII at the time of preleptot ene spermatocyte migration across the BTB, similar to TGF-b3 and TNF-a. The effects of cytokines and testosterone on testicular functions are multiple. However, in a latest study [6], the P.I. has shown that both cytokines and testosterone accelerate the kinetics of integral membrane protein endocytosis in Sertoli cells in vitro with functional BTB. In this instance, cytokines induce the endocytosed proteins (e.g., occludin) to late endosomes for degradation whereas testosterone promotes their recycling back to the cell surface. It is postulated that at defined stages of the spermatogenic cycle, cytokines contribute to the “destabilization” of the TJ fibrils at the apical portion of the migrating pr eleptotene spermatocytes, facilitating cell migration; whereas androgen promotes the “transcytosis” of the internalized integral membrane proteins from the apical to the basal region of the migrating germ cells to facilitate the assembly of new TJ fibrils, so as to maintain the im munological barrier during the epithelial cycle. How do testosterone and cytokines exert their differential actions on this junction dynamics is not known. However, this is likely mediated via their effects on extracellular matrix (ECM) components: collagens, proteases (e.g., matrix metalloproteases, MMPs, such as MMP-9), and protease inhibitors (e.g., tissue inhibitors of metalloproteases, TIMPs), thereby reducing the steady-state levels of integral membrane proteins at the BTB, and destabilizing the BTB to facilitate germ cell migration. The P.I. has the following specific aims to generate a comple te study to vigorously examine the actions of testosterone and cytokines on BTB dynamics at the cellular and subcellular levels. In this seed funding period, work on Specific Aim 1 will be performed. After which, a full proposal (Specific Aims 1 and 2) with initial results and backup findings from [6] will be submitted for GRF funding in the 2010-2011 exercise. Specific Aim 1: To investigate how cytokines are working in concert with extracellular matrix (ECM) proteins, such as collagens, proteases (e.g., MMP-9), and protease inhibitors (e.g., TIMP-1), to determine the steady-state levels of inte gral membrane proteins at the BTB, inducing transient BTB “opening” to facilitate preleptotene spermatocyte migration during spermatogenesis. Specific Aim 2: To delineate the mechanism(s) utilized by the testis to maintain the BTB integrity regarding the opposing effects of cytokines (or NC1 domain) and testosterone on the ba rrier function during the seminiferous epithelial cycle of spermatogenesis. Literature cited: 1. Lui WY and Lee WM (2008) Mechanisms of reorganization of cell-cell junctions in the testis. Frontiers in Biosciences 13:6775-6786. 2. Li MWM, Xia WL, Mruk DD, Wang Q, Yan HHN, Siu MKY, Lui WY, Lee WM and Cheng CY (2006) TNFa can reversibly disrupt the blood-testis barrier (BTB) and impair Sertoli-germ cell adhesion – a novel mechanism to regulate junction dynamics during sperm atogenesis. Journal of Endocrinology 190:313-329. 3. Xia WL, Mruk DD, Lee WM and Cheng CY (2005) Cytokines and junction restructuring during spermatogenesis – a lesson to learn from the testis. Cytokine & Growth Factor Reviews 16:469-493. 4. De Gendt K, Swinnen JV, Saunders PT, Schoonjans L, Dewerchin M, Devos A, Tan K, Atanas sova N, Claessens F, Lecureuil C, Heyns W, Carmeliet P, Sharpe RM, Verhoeven GA (2004) Sertoli cell-selective knockout of the androgen receptor causes spermatogenic arrest in meiosis. Proc. Natl. Acad. Sci. USA 101: 1327-1332. 5. Zhang JY, Wong CH, Xia WL, Mruk DD, Lee NPY, Lee WM and Cheng CY (2005) Regulation of Sertoli-germ cell adherens junction dynamics via changes in prote in-protein interactions of the N-cadherin-b-catenin protein complex which are possibly mediated by c-Src and MTMR2: an in vivo study using an androgen suppression model. Endocrinology 146:1268-1284. 6. Yan HHN, Mruk DD, Lee WM and Cheng CY (2008) Blood-testis barrier dynamics are regulated by testosterone and cytokines via their differential effects on the kinetics of protein endocytosis and recycling in Sertoli cells. FASEB J 22:1945-1959.


Project Title: 34th FEBS (Federation of the European Biochemical Societies) Congress IFN-gamma and TNF-alpha downregulate the expression of Junctional Adhesion Molecule-C (JAM-C) through transcriptional and post-translational controls
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Cell junction dynamics at stage VIII of the seminiferous epithelial cycle -- coordination between spermiation and blood-testis barrier restructur ing
Investigator(s): Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2009
Abstract:
During spermatogenesis, preleptotene/leptotene spermatocytes at the basal compartment traverse the blood-testis barrier (BTB) at stages ~VIII-IX of the seminiferous epithelial cycle in adult rat testes, entering the adluminal compartment for further development [1]. This event takes place concurrently with spermiation wherein fully developed spermatids (i.e., spermatozoa) detach from the epithelium at the luminal edge, enterin g the tubule lumen for their eventual maturation in the epididymis. The P.I. seeks to study the mechanism that regulates and coordinates these events. The idea was based on a recent study in which a blockade of the laminin function at the apical ES by specific antibodies led to spermatid exfoliation and BTB restructuring [2] showing that a disruption of the apical ES may lead to a transient BTB disruption. This illustrates a plausible physiological link between these two ultrastr uctures. The apical ES is a testis-specific adherens junction (AJ) type that anchors developing spermatids to the Sertoli cell in the epithelium during spermatogenesis [3]. It has properties of both AJ and focal contacts. For instance, many proteins that are restricted to the cell-matrix interface at the focal contacts, such as integrins, laminins, and collagens are found at the apical ES. In adult rat testes, one of the major cell adhesion complexes at the apical ES is the laminin-333/alpha6beta1 integrin complex [3]. Indeed, laminin gamma3 chain was first identified as a non-basement laminin at the apical ES in mouse testes [4]. Subsequent studies in adult rat testes have shown that laminin gamma3, alpha3 and beta3 chains residing in the elongating/elongated spermatids form a protein complex known as laminin-333 (2), which is the bona fide partner of the alpha6beta1-integrin restricted to Sertoli cells [5,6] constituting the laminin-333/alpha6beta1-integrin adhesion complex at the apical ES. When the laminin-333 function was compromised by using blocking antibodies, spermatid sloughing from the epithelium was detected [3]. Furthermore, this laminin/integrin complex is associated with proteases: matrix metalloprotease-2 (MMP-2), membrane-type 1 (MT1)- MMP; and tissue inhibitor of metalloproteases-2 (TIMP-2) [7]. These findings suggested that the activation of MMP-2 by MT1-MMP and TIMP-2 at the apical ES during spermiation could cleave laminin-333 to generate the biologically active laminin fragments. Indeed, there are reports illustrating that fragments of laminin chains that arise under physiological and pathophysiological conditions are biologically active peptides, regulatin g cell migration, protein production and/or activation, inflammatory responses, and others [8-10]. Thus, it is possible that fragments of laminin chains released from the apical ES during spermiation could regulate the BTB in the testis. This has prompted us to study the effects of laminin fragments on BTB restructuring. Subsequently, our latest results published in PNAS [11] have shown that specific laminin fragments: lamini n gamma3 chain domain IV (Lam g3DIV) and laminin beta3 chain domain I (Lamb3DI) are bioactive peptides regulating BTB restructuring. This study provides compelling evidence that during spermatogenesis there exists an autocrine-based regulatory axis (apical ES-BTB-hemidesmosome) coordinating spermiation and BTB restructuring. In this proposal, the PI provides a plan of follow-up studies to address the underlying mechanisms since this “apical ES-BTB-hemidesmosome” axis must be vigorously characterized, so that this information can be helpful to investigators in the field to study the biology and regulation of spermatogenesis. Additionally, this application will shed lights in the development of innovative male contraceptive, such as by using the laminin peptide to compromise spermatogenesis. This proposal is innovative, hypothesis driven, mechanistic in nature and based on recent findings published in leading journals. Specific Aim 1. Origin of the laminin fragments and their regulation: Is the production of laminin fragments stage-specific? Specific Aim 2. Mechanism(s) of action of the laminin fragment: (a) Is it mediated via integrin receptor and/or non-integrin-based proteins? Are non-receptor protein tyrosine kinases (e.g., FAK and c-Src) at the BTB and apical ES serve as the downstream signal transducers? Literature cited: 1. Russell LD. Movement of spermatocytes from the basal to the adluminal compartment of the rat testis. Am J Anat 1977; 148, 313-328. 2. Yan HHN, Cheng CY. Laminin a3 forms a complex with b3 and g3 chains that serves as the ligand for a6b1-integrin at the apical ectoplasmic specialization in adult rat testes. J Biol Chem 2006; 281 17286-17303. 3. Yan HHN, Mruk DD, Lee WM, Cheng CY. Ectoplasmic specialization: a friend or a foe of spermatogenesis? BioEssays 2007; 29, 36-48. 4. Koch M, Olson PF, Albus A, Jin W, Hunter DD, Brunken WJ, Burgeson RE, Champliaud MF. Characterization and expression of the laminin g3 chain: a novel, non-ba sement membrane-associated, laminin chain. J Cell Biol 1999; 145, 605-618. 5. Palombi F, Salanova M, Tarone G, Farini D, Stefanini M. Distribution of b1 integrin subunit in rat seminiferous epithelium. Biol Reprod 1992; 47, 1173-1182. 6. Salanova M, Stefanini M, De Curtis I, Palombi F. Integrin receptor a6b1 is localized at specific sites of cell-to-cell contact in rat seminife rous epithelium. Biol Reprod 1995; 52, 79-87. 7. Siu MKY, Cheng CY. Interactions of proteases, protease inhibitors, and the b1 integrin/laminin g3 protein complex in the regulation of ectoplasmic specialization dynamics in the rat testis. Biol Reprod 2004; 70, 945-964. 8. Koshikawa N, Schenk S, Moeckel G, Sharabi A, Miyazaki K, Gardner H, Zent R, Quaranta V. Proteolytic processing of laminin-5 by MT1-MMP in tissues and its effects on epithelial cell morphology. FASEB J 2004; 18, 364-366. 9. Ogawa T., Tsubota Y., Hashimoto J., Kariva Y., Miyazaki K. The short arm of laminin g2 chain of laminin-5 (laminin -332) binds syndecan-1 and regualtes cellular adhesion and migration by suppressing phosphorylation of integrin b4 chain. Mol Biol Cell 2007; 18, 1621-1633. 10. Remy L., Trespeuch C., Bachy S., Scoazec J.Y., Rousselle P. Matrilysin 1 influences colon carcinoma cell migration by cleavage of the laminin-5 b3 chain. Cancer Res 2006 ; 66, 11228-11237. 11. Yan HHY, Mruk DD, Wong EWP, Lee WM, Cheng CY. An autocrine axis in the testis that coordinates spermiation and blood-testis barrier restructuring during spermatogenesis. Proc Natl Acad Sci USA 2008; 105: 8950-8955.


List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents bl ood-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Lui W.Y. and Lee W.W.M. , Molecular mechanisms by which hormones and cytokines regulate cell junction dynamics in the testis, Journal of Molecular Endocrinology . 2009, 43: 43-51.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Lee YK

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Liao S. , Liu Y. , Siu D.C.W. , Zhang Y. , Lai K.W.H. , Au K.W. , Lee Y.K. , Chan Y.C. , Yip P.M.C. , Wu E.X. , Lau C.P. , Wu Y., Li R.A. and Tse H.F. , Pro-arrhythmic Risk of Embryonic Stem Cell-Derived Cardiomyocytes Transplantation in Infarcted Myocardiu m. Heart Rhythm. , 2010.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Lee YK

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Liao S. , Liu Y. , Siu D.C.W. , Zhang Y. , Lai K.W.H. , Au K.W. , Lee Y.K. , Chan Y.C. , Yip P.M.C. , Wu E.X. , Lau C.P. , Wu Y., Li R.A. and Tse H.F. , Pro-arrhythmic Risk of Embryonic Stem Cell-Derived Cardiomyocytes Transplantation in Infarcted Myocardium. Heart Rhythm. , 2010.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Leung FCC

Project Title: Cloning of the viral genes from the newly identified SARS coronavirus
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: VCO SARS Research Fund
Start Date: 07/2003
Abstract:
To clone all the viral gene into vector and these cloned genes will be then be used as reagents by us and other as the first step for investigation.


Project Title: Development of a rapid high throu ghput RT-PCR assay to detect SARS-CoV
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: VCO SARS Research Fund
Start Date: 07/2003
Abstract:
To develop a 96-wells RT-PCR platform assay for the detection of the coronavirus.


Project Title: Isolation and characterization of a PCV2 virus causing postweaning multisystemic wasting syndrome in pigs
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To isolate and characterize the PCV2 virus that causes the Postweaning multisystemic wasting syndrome (PMWS) in pigs.


Project Title: International Conference on Farm Animal Endocrinology Characterization of the 5'-Flanking Transcriptional Regulatory Region of the Chicken Growth Hormone Gene
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2004
Abstract:
N/A


Project Title: Characterization of the angiotensi n-converting enzyme 2 receptors from various animals and the use of pseudotyped virus to correlate the receptor-binding to susceptibility of SARS-CoV infection
Investigator(s): Leung FCC
Department: Zoology
Source(s) of Funding: Research Fund for the Control of Infectious Diseases - Full Grants
Start Date: 01/2007
Abstract:
To identify the susceptible animals to severe acute respiratory syndrome associated coronavirus SARS-CoV and SARS-like bat CoV through a molecular approach.


Project Title: 2009 Conference for Research Workers in Animal Diseases A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)
Investigator(s): Leung FCC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 12/2009
Abstract:
N/A


List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Hui R.K.H. , Wang K.X. and Leung F.C.C. , Effects Of Nsp2 Deletions On PRRSV Genome And Replicatoin Efficiency., International PRRS Symposium 2009, National Pork Board . 2009.
Leung F.C.C. , American Association for the Advancement of Science (AAAS) Fellow 2009 . 2009.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J., Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Wang Y., Li J., Kwok H.Y.A. , Ge W. and Leung F.C.C. , A novel prolactin-like protein (PRL-L) gene in chickens and zebrafish: cloning and characterization of its tissue expression, General and Comparative Endocrinology . 2009, 166: 200-210.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.
Xi Y. , Huang B. , Djurisic A. , Chan M.N. , Leung F.C.C. , Chan W.K. and Au D.T.W., Electrodeposition for antibacterial nickel-oxide-based coatings, Thin Solid Films . Amsterdam, Elsevier B.V., 2009, 517: 6527-6530.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intra-species Diversity of SARS-Like Coronaviruses (CoVs) in Rhinolophus sinicus and Its Implications on the Origin of SARS-CoVs in human., Journal of general virology . 2009, 91: 1058-1062.
Yuan J., Hon C.C. , Li Y., Wang D., Xu G., Zhang H., Zhou P., Poon L.L.M. , Lam T.Y. , Leung F.C.C. and Shi Z., Intraspecies diversity of SARS-like coronaviruses in Rhinolophus sinicus and its implications for the origin of SARS coronaviruses in humans, Journal of General Virology . 2009, 91: 1058-1062.


Researcher : Leung HYM

List of Research Outputs

Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.


Researcher : Leung KCJ

List of Research Outputs

Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Leung KMY

Project Title: Ecology, physiology and toxicology of Stomatopoda in Hong Kong
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 09/2002
Abstract:
To document the biodiversity of Stomatopoda in the subtital marine environment of Hong Kong; to study the population dynamics, ecology and physiology of five commercially important stomatopod species, Harpiosquilla harpax, Dictyosquilla foveolata, Miyakea nepa, Oratosquill a oratoria and Oratosquillina interrupta in the selected study locations; to investigate if there are any seasonally variations in the concentrations of pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the tissues of these five stomatopod species; to test and establis h the relationship between fitness parameters, physiological indices and pollution burdens in the stomatopods.


Project Title: Aquatic ecological risk assessment: comparison of tropical and temperate species sensitivity to chemicals
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: Other Funding Scheme
Start Date: 09/2002
Abstract:
To compare the species sensitivity distributions for temperate and tropical organisms exposed to individual chemicals; to identify specific chemical groups, classified by mode of action or physico-chemical properties, for which technically sound estimates of tropical PNECs can be made/predicted on the basis of temperate toxi city data; to validate these predictions through the generation/compilation of extensive ecotoxicity datasets for a number of mo del substances; to establish a procedure to estimate tropical PNECs for the selected substances. Existing data will be supplemented by new ecotoxicity data where these are likely to result in improved confidence in the estimation of tropical PNECs.


Project Title: Ecotoxicity of binary mixtures of antifouling biocides and copper to selected tropi cal marine organisms: Implications for derivation of environmentally realistic water quality criteria
Investigator(s): Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 11/2007
Abstract:
To investigate the acute and chronic toxicities of eight common synthetic antifouling biocides alone and in combination with copper (Cu) to a suite of tropical/sub-tropical marine organisms (including plant, invertebrate and vertebrate). To derive environmentally relevant water quality criteria (WQC) for these compounds at various environmentally realistic Cu levels (0-20 µg/L) using a novel approach.


Project Title: Time-series and spatial statistical studies on marine water quality monitoring data in Hong Kong: Implications of the effectiveness of environmental policy and management, and definition of water pollution control zones
Investigator(s): Leung KMY, Li WK
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2010
Abstract:
1. To development of time-series models to partially characterise and identify the critical time points in terms of water quality improvement over the past; and 2. To explore suitable spatial models to redefine the water pollution control zones for better water quality management in Hong Kong.


Project Title: The Experimental Biology 2010 Meetin g A fitness cost for thermal tolerance in a marine copepod: Implication on biological effects of global warming
Investigator(s): Leung KMY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 04/2010
Completion Date: 04/2010
Abstract:
N/A


List of Research Outputs

Bao W.W. , Qiu J.W., Lam M.H.W. and Leung K.M.Y. , Acute toxicities of five commonly used antifouling booster biocides to selected tropical/subtropical marine species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Acute toxicities of zince pyrithione alone and in combination with copper to marine autotrophic species, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Lui G.C.S. and Leung K.M.Y. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Bao W.W. , Leung K.M.Y. and Lui G.C.S. , Mixture toxicities of zinc pyrithione and copper to subtropical marine organisms: implications on deriving environmentally realistic water quality criteria, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Bao W.W. , Koutsaftis A. and Leung K.M.Y. , Temperature-dependent toxicities of chlorothalonil and copper pyrithione to the marine copepod Tigriopus japonicus, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Cheung M.M.S. , Leung H.Y.M. and Leung K.M.Y. , Vignette 8.2: The use of neogastropods as indicator of tributyltin contamination along the South China coast, In: Newman, M.C. (eds), Fundamentals of Ecotoxicology, 3rd Edition . CRC Press, Boca Raton, 2010, 222-226.
Guomundsdottir L.O., Ho K.Y. , Lam C.W. , Svavarsson J. and Leung K.M.Y. , Long-term temporal trends (1992-2008) of imposex and organotin contamination in the dogwhelk Nucella lapillus along the Icelandic coast, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Kwok W.H.K.P. and Leung K.M.Y. , Marine Pollution Bulletin Highly Cited Author Award 2005-2009, Marine Pollution Bulletin, Elsevier . 2010.
Leung K.M.Y. , A fitness cost for thermal tolerance in a marine copepod: implication on biological effects of global warming, an invited lecture at at the Mini-Symposium on Biolo gical Consequences of Global Change in the Experimental Biology 2010 congress, which was organised by the American Association of Anatomists and International Society of Zoological Sciences, was held during 24-28 April 2010 at Anaheim Convention Centre, Anaheim, U.S.A. . 2010.
Leung K.M.Y. and Bao W.W. , A unifying model for predicting temperature-dependent toxicity of pollutants: an insight to the interacting effect of climate change and chemical pollution, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung K.M.Y. , Award for Service Contribution 2009-2010, Faculty of Science, The University of Hong Kong . 2010.
Leung K.M.Y. , Comparison of tropical and temperate aquatic species sensitivities to chemicals: implications for ecological risk assessment and water quality management, an invited plenary lecture at the Workshop on Ecosystem Risk Assessment, which was organised by the Australasian Society for Ecotoxicology and held during 14-15 June 2010, in Madang, Papua New Guinea . 2010.
Leung K.M.Y. , Endocrine disrupting chemicals (EDCs) in Hong Kong waters: What we know, don't know and should know, an invited lecture at the International Symposium on the Biomonitoring and Biomarker of EDCs in Coastal and Marine Environments, organised by Ministry of Land, Transport and Maritime Affairs, Korea and National Eisheries Research and Development Institute, held on 17 September 2009, in Busan, Korea . 2009.
Leung K.M.Y. , Environmental risk assessment: a major paradigm shift in environmental management, and Field species distribution for detection of environmental changes, two invited lectures delivered at the United Nations' PEMSEA Regional Training Course on Novel Technology for Marine Environmental Management, organised by Partnerships in Environmental Management for the Seas of East Asia, held during 19-21 November 2009, in Manila, Philippine s . 2009.
Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung M.C.C., Hui J.C.T., Zurcher N.A. , Yuan D.X. and Leung K.M.Y. , Trace metals and methyl mercury in sharks' fins: potential health risk for consumers, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zool ogy, July 7-10, 2009. Beijing, China . 2009.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea: Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Qiu J.W., Chan K.M. and Leung K.M.Y. , Assessment of tributyltin contamination in Hong Kong coastal waters using Thais clavigera as a biomonitor: an update on the spatial and seasonal patterns, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Rhodes J.R., Grist E.P.M., Kwok K.P.W.H. and Leung K.M.Y. , A Bayesian mixture model for estimating intergenerat ion chronic toxicity, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wong L.C., Kwok K.P.W.H. , Leung K.M.Y. and Wong C.K., Relative sensitivity distribution of freshwater planktonic crustaceans to trace metals, Human and Ecological Risk Assessment . 2009, 15: 1335-1345.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enha nce uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor response s in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City Universit y of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Yeung W.Y. and Leung K.M.Y. , Effects of tissue types, animal size, nutritional status and metal exposure on the RNA/DNA ratio in various tissues to the green-lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Yeung W.Y. and Leung K.M.Y. , Spatio-temporal variations in metal accumulation, RNA/DNA ratio, energy reserves and condition index in transplanted green-lipped mussels Perna viridis in sub-tropical Hong Kong waters, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Zhao Z.Y., Gu J.D. , Li H.B., Li X.Y. and Leung K.M.Y. , Disinfection characteristics of the dissolved organic fractions at several stages of a conventional drinking water treatment plant in Southern China, Joural of Hazardous Materials . 2009, 172: 1093-1099.


Researcher : Leung TK

List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.


Researcher : Leung TY

List of Research Outputs

Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Leung T.Y. , Wang Y. and Leung K.M.Y. , Differential proteomic responses in adductor muscle and hepatopancreas of the green-lipped mussel Perna viridis to stresses induced by cadmium and hydrogen peroxide, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zoology, July 7-10, 2009. Beijing, China . 2009.
Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea: Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Li ETS

Project Title: Nutritional benefits of dietary fiber supplementation in hospitalized geriatrics
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1997
Abstract:
To improve gentle bowel fitness, relieve constipation and improve serum lipid profile of institutionalized geriatric patients via dietary fiber supplementation.


Project Title: An evaluation on the antioxidant effects of Lycium barbarum L. and its supplementation on cataract formation in rats
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To systematically examine the antioxidant properties of Lycium barbarum L. and evaluate the effect of its supplementation on cataract development in rats.


Project Title: Anti-cataract effects of Lycium barbarum L and Momordica charantia
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2004
Abstract:
To systematically examine the antioxidant properties of Lycium barbarum L. and Momordica charantia and evaluate the effects of supplementation on cataract development in rats.


Project Title: The CSCN 5th Annual Scientific Meeting Bitter Melon Supplementation Changes Expression of Genes Controlling Lipid Metabolism in Diet-induced Obese Rats
Investigator(s): Li ETS
Department: Zoology
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2006
Abstract:
N/A


Project Title: Offsetting the Adverse Effects of Maternal Overnutrition by Bitter Melon Supplementation
Investigator(s): Li ETS
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
Metabolic syndrome (MS) posts a serious health concern worldwide. The etiology of MS is complex and a lot of attention has been given to the impact of perinatal nutrition because substantial evidence suggest maternal nutrition has a trans-generation effect on disease risk. In fact, both under- and overnutrition are known to predispose offspring to develop phenotypes characteristics of MS. This study will focus on examining in utero overnutrition as a predisposing factor. High fat intake is acknowledged to attribute to the high incident of chronic degenerative disease s. Fetal programming effect is well established. Offspring of rats fed a high fat diet during pregnancy had impaired glucose homeostasis. There is a positive association between birth weight and later BMI (and obesity). furthermo re, macrosomic infants have higher cardiovascular disease risk. Hence, the relationship between birth weight and type 2 diabetes (T2D) is U-shape. It should be reminded that increasing prevalence and younger age of MS onset takes place at time when fat consumption follows a decreasing trend. However, the consumption of another macronutrient, fructose, had steadily increased in the past 30 years. High fructose diet is also know n to precipitate MS. In addition to changes in energy and macronutrient supply, developmental programming can take place with perinatal exposure to certain dietary ingredients. For instance, isoflavones given to dams during pregnancy and lactation provide cardioprotection to offspring in adulthood. Reduced risk of obesity has also been demonstrated in Avy mouse. When genistein was given to a/a females two weeks prior to mating with Avy/a males, the coat color of the heterozygous yellow agouti pups was shifted to pseudoagouti. These results led us to reason that other bioactive ingredients, known to influence energy metabolism and glucose homeostasis, introduced at pregnancy and lactation might be benef icial. In this context, we have the experience in the use of botanical / herbal preparations in counteracting the phenotype characteristics of MS. We have documented the beneficial effects of bitter melon juice and its supplementation in the diet results in lower blood glucose and triglyceride; and less body fat accumulation. The molecular mechanisms involved include elevated expression of uncoupling protein in white adipose tissue and lipolytic enzymes in skeletal muscles. Whether bitter melon supplementation could offset the adverse metabolic effect of fructose has not be examined. The overall objective of this proposal is to test the hypothesis that supplementation of bitter melon extract from pe riconceptual through lactation period can alleviate the negative impact of maternal overnutrition induced by fructose on chronic disease risk of offspring. Specific objectives: a. To establish the effects of maternal bitter melon supplementation on fetal programming in offspring from fructose fed dams. c. To examine the molecular mechanisms that counteract metabolic syndrome imprinted by maternal overnutrition.


List of Research Outputs

He M., Li E.T.S. , Harris S., Yau C.Y. and Anderson G.H., The Canadian Global Village Reality: A look at anthropo metric surrogate cut-offs and metabolic abnormalities among East-Asian, South-Asian and European descendant. , Canadian Family Physician . Canada, College of Family Physicians of Canada, 2010, 56: e174-182.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption , Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratr ol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G ., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li H

List of Research Outputs

Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Li H. and Chye M.L. , Arabidopsis acyl-coenzyme-A binding 3 interacts with a lysophospholipase, The 3rd Asian Symposium on Plant Lipids, Yokohama, Japan, 26th - 30th Nov, 2009, Session 4, S4-3, p. 46, Invited talk . 2009.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.


Researcher : Li J

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J. , Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.


Researcher : Li J

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Repro ductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Sympo sium . 2009, 74.
Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor respons es in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Li J. , Bao W.W. and Leung K.M.Y. , Temperature-dependent physiological responses of the marine medaka Oryzias melastigma to copper exposure, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Li R., Fan W., Tian G., Zhu H., He L., Cai J., Huang Q., Cai Q., Li B., Bai Y., Zhang Z., Zhang Y., Wang W., Li J. , Wei F., Li H., Jian M., Li J. , Zhang Z., Nielsen R., Li D., Gu W., Yang Z., Xuan Z., Ryder O., Leung F.C.C. , Zhou Y., Cao J., Sun X., Fu Y., Fang X., Guo X., Wang B., Hou R., Shen F., Mu B., Ni P., Lin R., Qian W., Wang G., Yu C., Nie W., Wang J., Wu Z., Liang H., Min J., Wu Q., Cheng S., Ruan J., Wang M., Shi Z., Wen M., Liu B., Ren X., Zheng H., Dong D., Cook K., Shan G., Zhang H., Kosiol C., Xie X., Lu Z., Zheng H., Li Y., Steiner C.C., Lam T.Y. , Lin S., Zhang Q., Li G., Tian J., Gong T., Liu H., Zhang D., Fang L., Ye C., Zhang J., Hu W., Xu A., Ren Y., Zhang G., Bruford M.W., Li Q., Ma L., Guo Y., An N., Hu Y., Zheng Y., Shi Y., Li Z., Liu Q., Chen Y., Zhao J., Qu N., Zhao S., Tian F., Wang X., Wang H., Xu L. and et al .., The sequence and de novo assembly of the giant panda genome, Nature . 2009, 463 (7279): 311-317.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.


Researcher : Li L

List of Research Outputs

Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.


Researcher : Li M

List of Research Outputs

Li M. , Hong Y., Klotz M. and Gu J.D. , A comparison of primer sets for detecting 16S rRNA and hydrazine oxidoreductase genes of anaerobic ammonium-oxidi zing bacteria in marine sediments, Applied Microbiology and Biotechnology . Heidelberg, Germany, Springer, 2010, 86: 781-790.
Li M. , Yang H. and Gu J.D. , Phylogenetic diversity and axial distribution of microbes in the intestinal tract of the polychaete Neanthes glandicincta, Microbial Ecology . New York, Springer, 2009, 58: 892-902.


Researcher : Li WMM

List of Research Outputs

Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biology. . 2009, 41: 2302-2314.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Lie PYP

List of Research Outputs

Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents bloo d-testis barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.


Researcher : Lim BL

Project Title: High-yield GM Camelina for biofuel application
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 06/2009
Completion Date: 05/2010
Abstract:
On 30 Jan 2009, the Japan Airline (JAL) successfully conducted a test flight (Boeing 747-300) using a biofuel primarily refined from camelina. One of the four engi nes used a 50%/50% blend of biofuel and traditional kerosene fuel. The biofuel was a mixture of three second-generation biofuels: camelina (84%), jatropha (under 16%), and algae (under 1%).  No modifications to the aircraft or engine were required for the biofuel. Camelina is now a hot species in biofuel. It can grow in margin al lands with low moisture, low fertility, or saline soils. It also has low requirements for fertilizers, pesticides, and energy, which provide a better soil erosion control. http://www.montana.edu/biobased/projects/CamelinaInfo .html We have a proprietary GM technology that can speed up the growth of Arabidopsis and increased its seed yield by 40-50%. Both Camelina and Arabidopsis belong to the Brassicaceae Family and are very close to each other. It is very likely that the success of our technology in Arabidopsis will replicate in Camelina. The effect of the technology can be seen in the following links: http://hk.youtube.com/watch?v=Yq842GWKdYw http://hk.youtube.com/watch?v=8xS8iVqToK8


Project Title: Platform Technology for Yield Imp rovement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL, Phang TH
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Support Programme (Tier 3)
Start Date: 12/2009
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the patent-pending transgene. This project is important for HKU to stre ngth the patent portfolio of this platform technology before the multi-billion agrobiotechnology companies (Monsanto, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumve nt our technology by finding and patenting the genes located upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Camelina with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation bi ofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants.


Project Title: Platform Technology for Yield Improvement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 01/2010
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the patent-pending transgene. This project is important for HKU to strength the patent portfolio of this platform technology bef ore the multi-billion agrobiotechnology companies (Monsanto, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumvent our technology by finding and patenting the genes loca ted upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Camelina with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation biofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants


Project Title: Platform Technology for Yield Impr ovement in Agriculture, Forestry and Biofuels
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 01/2010
Abstract:
The objective of this project is to discover the genes upstream and downstream of our patent pending transgene (US application no: 61/138,918) that could produce a similar or better performance than the pat ent-pending transgene. This project is important for HKU to strength the patent portfolio of this platform technology before the multi-billion agrobiotechnology companies (Monsant o, Pioneer, Syngenta, Bayer CropScience, etc) can crack/circumvent our technology by finding and patenting the genes located upstream and downstream of the pathway. Another objective is to produce transgenic rapeseed and Cameli na with greatly improved seed yields. These seeds will have great commercial values because rapeseed and Camelina seeds are major sources of biodiesel and aviation biofuel, respectively. The success in these plants can also prove the practicability of our platform technology in other plants


Project Title: 12th World Congress of the International Association for Plant Biotechnology Over-expression of a novel Arabidopsis phosphatase results in accelerated growth and increased seed yield
Investigator(s): Lim BL
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Kuang R. , Chan K.H. , Yeung E. and Lim B.L. , Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis 1[W][OA] , Plant Physiology . 2009, 151: 199-209.
Liang C., Tian J., Lam H.M., Lim B.L. , Yan X. and Liao H., Biochemical and Molecular Characterization of PvPAP3, a Novel Purple Acid Phosphatase Isolated from Common Bean Enhancing Extracellular ATP Utilization, Plant Physiology . 2009, 152: 854-865.
Lim B.L. , Leung Y.C. , Yung K.F. , Leung M.K.H. , Mah D.N.Y. , Lam J.C.K. and Hills P.R. , Conference Presentation: "Development of Biofuel Technologies and Policy", at the Initiative on Clean Energy and Environment’s Review Workshop, Shenzhen, January 8, 2010 .
Lim B.L. , TonB-Dependent Receptors in Nitrogen-Fixing Nodulating Bacteria., Microbes and Environments . 2010, 25: 67–74.
Wang X.R., Wang Y.X., Jiang T., Lim B.L. , Yan X.L. and Liao H., Overexprressing AtPAP15 enhances phosphorus efficiency in Soybean 1[W][OA] , Plant Physiology . 2009, 151: 233-240.
Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Liu H

List of Research Outputs

Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essent ial for chloroplast function., New Phytologist . 2010, 187: 83-105.


Researcher : Liu J

List of Research Outputs

Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Liu M

List of Research Outputs

Sadovy Y.J. , Liu M. and Suharti S., Gonadal development in a giant threatened reef fish, the humphead wrasse Cheilinus undulatus, and its relationship to international trade, Journal of Fish Biology . 2010, 77: 706-718.


Researcher : Lo CSC

Project Title: Promoter analysis of a pathogen-in ducible dihydroflavonol reductase gene in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 09/2009
Abstract:
Sorghum (Sorghum bicolor) is a tropical cereal best known for its unusual tolerance of hot and dry environments and its wide range of natural products (secondary metabolites) synthesized. We are interested in sorghum because it produces a unique class of flavonoid phytoalexins, the 3-deoxyanthocyanidins, as an essential component of defense mechanism against pathogen infection. These compounds are distinct from the widely distributed anthocyanidins in which they lack a C-3 hydroxyl group and they occur naturally as aglycones (Fig. 1). We have identified the 3-deoxyanthocyanidins as luteolinidin, apigeninidin, and their respective methyl ethers [1-3]. Complete in vitro toxicity to fungal pathogens occurred at concentrations less than 10 μM for each compound [1]. We demonstrated that the 3-deoxyanthocyanidin phytoalexins are significant for resistance against Colletotrichum sublineolum [4], the causal agent of anthracnose which is a major disease affecting the worldwide production of both corn and sorghum. In recent years, flavonoids such as anthocyanins have been associated with health beneficial properties, such as lowering the risks of cardiovascular diseases and cancers. Our recent studies demonstrated that the 3-deoxyanthocyanidins were more effective than their 3-hydroxylated analogs of anthocyanidins in suppressing the proliferation of two cancer cell lines [5]. The health benefits of 3-deoxyanthocyanidins to both plants and humans highlighted the importance for understandin g the regulation of their biosynthesis pathway. Flavonoid biosynthesis begins with chalcone synthase which directs the flow of carbon from the phenylpropanoid pathway to the formation of naringenin from which both anthocyanidins and 3-deoxyanthocyandins are derived (Fig. 2). The final steps in the 3-deoxyathocyanidin pathway are still unknown. Reduction and dehydroxylation reaction steps similar to those in the anthocyanidin pathway have been proposed, but without the involvement of flavanone 3-hydroxylase (F3H) which introduces the C-3 hydroxyl group in flavonoids (Fig. 2). The enzyme dihydroflavonol reductase (DFR) participates in both branch pathways leading to anthocyanidin and 3-deoxyanthocyanidin biosynthesis. Recently we demonstrated the differential expression of two DFR cDNAs (SbDFR1 and SbDFR2) in sorghum seedlings responding to differ ent stimuli (Fig.3). In response to light, etiolated seedlings accumulate anthocyanin pigments in the mesocotyl tissues. When they are inoculated with fungal pathogens, 3-deoxya nthocyanidins accumulate as phytoalexins. As shown in Fig. 3, SbDFR1 was specifically induced during light-induced anthocyanin accumulation while SbDFR2 was specifically induced during pathogen-induced 3-deoxyanthocyanidin synthesis in sorghum seedlings. Their encoded proteins are highly conserved with over 80% sequence identity. More recently, we demonstrated that both cDNAs encode functional DFR enzymes through complementation analysis in Arabidopsis DFR mutants (unpublished data). Furthermore, recombinant DFR proteins were found to accept both dihydroflavonol and flavanone substrates (unpublished data), which are the precursors for anthocyanidins and 3-deoxyanthocyanidins, respectively. Apparently the two DFR proteins have similar biochemical properties and the biosynthesis of 3-deoxyanthocyanidins following pathogen infection is mainly regulated at transcriptional level. There have been few studies on the transcriptional regulation of 3-deoxyflavonoid biosynthesis in plants. In maize, formation of phlobaphene pigments (polymers of flavan-4-ol s, which are 3-deoxyflavanols) in pericarp is controlled by the MYB transcription factor P1 which activates chalcone synthase, chalcone isomerase, and DFR genes but not F3H [6], so that the flavanones formed would not be hydroxylated at C-3. In a recent study, the sorghum the Y1 gene (a P1 homolog) was shown to be genetically linked to phlobaphene accumulation in pericarp [7]. However, the sorghum line (BTx623) which has a deletion allele of Y1 are still able to synthesize 3-deoxanthocyanidins following pathogen inoculation (our work), indicating that a different regulatory mechanism is involved during defense response. In this proposed study, we aim to identify the cis-elements located in the promoter of the pathogen-inducible SbDFR2 gene. First, we will isolate the promoter region by screening a sorghum genomic bacterial artificial chromosome (BAC) library. Sequence analysis will be performed to define the native promoter region and putative cis -elements by online computer programs. We will develop a transgenic Arabidopsis system for expression analysis of the reporter gene β-glucuronidase (GUS) driven by different 5’-truncated derivatives of the sorghum promoter to identify the region necessary and sufficient for pathogen induction. Finally we will perform DNA-protein binding assays to locate the pathogen-responsive cis-elements in the promoter. The major mechanism of differential gene expression is transcriptional regulation, which is controlled by transcription factors that bind to DNA cis-elements located in gene promoters. To underst and transcriptional regulation that leads to differential expression, genes must be experimentally linked with the corresponding transcription factors that regulate their expression. A powerful method of identifying protein-DNA interaction is the yeast one-hybrid screening system. A key to the success of such screening is the identification of cis-elements that are interacting with the transcription factors. Results from this study therefore will provide the necessary informati on for an RGC CERG application involving the identification and characterization of transcription factors that regulate the pathogen-induced biosynthesis of 3-deoxyanthocyanidins in sorghum.


Project Title: Non-targeted metabolite profiling of infected sorghum seedlings using an enhanced UPLC-TOF -MS technology platform
Investigator(s): Lo CSC, Chu IK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2009
Completion Date: 10/2010
Abstract:
Plants are unique in the richness and diversity of their secondary metabolism, collectively resulting in more than 200,000 natural products (or secondary metabolites) with different physiological roles in their unique habitats. Natural products are increas ing popular because of their perceived benefits, such as their anti-oxidation and anti-cancer activities. Sorghum is the fifth-ranking cereal crop in the world. The plant is best known for its unusual tolerance of hot and dry environment. In addition, sorghum are previously known to produce a range of natural products including dhurrin (a cyanogenic glycoside), sorgoleones (root exudates), and 3-deoxyanthocyanidins (antifungal phytoalexins). Our laboratory is interested in the synthesis of defense-rela ted metabolites in sorghum following infection by fungal pathogens. We have demonstrated that the 3-deoxyanthocyanidins are essential for resistance against Colletotrichum sublineolum (Lo et al. 1999), the causal agent of anthrac nose which is a major disease affecting the worldwide production of both corn and sorghum. These compounds are distinct from the widely distributed anthocyanin pigments by the absence of the C-3 hydroxyl group. We have also demonstrated that the 3-deoxyanthocyanidins are more effective than the anthocyanidins in suppressing the proliferation of two cancer cell lines (Shih et al. 2007). Recently, we have reported first example of a monocot stilbene synthase gene, SbSTS1, in sorghum and the gene is highly pathogen-inducible (Yu et al. 2005). This has led to the subsequent identification of the stilbene trans-piceid in infected sorghum seedlings. Although the stilbene metabolite was found to be non-essen tial for defense, its production may be manipulated for accumulation in the sorghum grains to enhance their nutraceutical values (Yu et al. 2008). Stilbene metabolites (e.g. resveratrol) are the well-recognized health-beneficial compounds commonly found in red wine and other grape-derived products. Recent advances in mass spectrometry (MS) technologies have allowed scientists to profile metabolites in a more robust and efficient manner. Gas chromatography-MS approaches have routinely been used to profile primary metabolites such as sugars, amino acids, and organic acids. On the other hand, liquid chromatography (LC)-MS approaches have been used for the analysis of secondary metabolites in different plant systems. Over the past few years, our laboratory has implemented a number of LC-MS/MS methodologies for targeted metabolite analysis in different plant systems. In particular, we have successfully implemented the use of a hybrid quadrupole-ion trap mass spectrometer for profiling, structural elucidation, and quantificatio n of stilbene and flavonoid metabolites in infected sorghum seedlings and transgenic Arabidopsis expressing different secondary metabolic enzymes. In the SbSTS1-transgenic Arabidopsis plants, cis-piceid (a rare stilbene isoform) was identified as the major stilbene metabolite (Yu et al. 2006) and a novel resveratrol glycoside (acetylhexoside) was also detected (Lo et al. 2007). In addition to the 3-deoxyanthocyanidins and stilbenes, there are a number of pathogen-induced unknown compounds which can be detected in C. sublineolum-infected sorghum seedlings by our routine HPLC-UV analysis, some of which may represent novel compounds with potential agricultural and nutritional applications. In addition, the maize pathogen Cochliobulus heterostrophus does not infect sorghum but is also able to cause rapid and intense accumulation of 3-deoxyanthocyanidins in the plant. This non-pathogen may also induce the accumulation of unique metabolites in sorghum. Non-targeted metabolite profiling experiments will therefore be necessary in order to obtain a comprehensive picture of the phytochemical changes in the plant following challenges by different fungal pathogens. In this regard, a robust separation approach with high resolving power is extremely essential for separation of complex samples into individual co mponents. Among the various LC platforms, ultra-performance liquid chromatography (UPLC) has emerged as a high-resolution separation technology with enhanced retention time reproducibility and increased peak capacity, maximizing the number of detectable components in profiling metabolite experiments. UPLC also allows extraction to be downsized to accommodate tissues of small quantities. Different mass analyzers coupled to LC separation have also been explored in metabolomics studies, but the time-of-fli ght (TOF) mass spectrometers provide mass information with higher accuracy and precision. The accurate mass values can be used to deduce empirical formulae for candidate compounds, at the 3-5 ppm range, significantly reducing the number of possible structures with molecular masse s of a few hundred Daltons. The major objective of this exercise is to generate a list of metabolite markers for sorghum seedlings inoculated with either C. sublineolum or C. heterotrophus. The metabolite markers will be cross-examined in cultivars with different disease responses to identify the potential compound essential for disease resistance in sorghum. Some of the differentially expressed metabolites may represent novel compounds and they will need to be subject to preparative HPLC purification and NMR analysis in fu ture investigations. In addition, we will seek to implement an enhanced UPLC-TOF-MS technology platform with increased peak capacity, higher resolution, and high mass-accuracy for systematic and non-targeted identification of met abolites in the investigations of plant natural products.


Project Title: XIV International Congress on Molecular Plant-Microbe Interactions Molecular dissection of pathogen-inducible flavonoid pathway in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Further dissections of the pathogen-inducible 3-deoxyanthocyanidin biosynthesis pathway in sorghum
Investigator(s): Lo CSC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
The cultivation of genetically uniform crop species over large areas of farmland frequently results in severe outbreaks of diseases with huge economic losses. In addition, the use of agrochemicals for disease control often leads to pollution and elevated production costs. Better understanding of the molecular mechanism s of disease resistance is essential for providing novel approaches to improve crop performance through traditional breeding and genetic engineering. In resistant responses to attempted infections, many plants deploy an array of antimicrobial compounds to halt pathogen developmen t. These infection-induced defense compounds are called “phytoalexins” which are secondary metabolites synthesized de novo from primary metabolites. We are interested in sorghum (Sorghum bicolor) because it produces a rare class of flavonoids, the 3-deoxyanthocyanidins, as phytoalexins for successful defense against fungal infection. 3-Deoxyanthocyanidins are pigmented compound s limited to a few plant species. They are the major pigments in sinningia flowers, silk tissues of some maize (=corn) cultivars, and sorghum bran. To our knowledge, pathogen-inducible biosynthesis of 3-deoxyanthocyanidins occurs only in sorghum. Structurally, 3-deoxyanthocyani dins are very similar to the more commonly found plant pigments, anthocyanins, except for the absence of C3-hydroxylation (Fig. 1). Anthocyanins from different sources have been shown to suppress cancer cell proliferation and induce apotosis (1, 2). Recently, we demonstrated that the 3-deoxanthocyanidins are more effective than anthocyanidins in suppressing the proliferation of the human HL60 and HepG2 cancer cell lines (3). In addition, the 3-deoxyanthocyanidins are more stable to pH, temperature, and light changes than the anthocyanins (4). They have absorption maxima lower than 480 nm, which is a feature potentially useful for the replacement of artificial yellow and orange pigments. Since there is also an increasing interest in natural food coloran ts with functional properties (4), 3-deoxyanthocyanidins are likely to be a good candidate with desirable attributes useful in food and nutritional applications. The health benefits of 3-deoxyanthocyanidins to both sorghum and human highlight the importance to elucidate their route of biosynthesis. Flavonoid formation begins with a condensation reaction catalyzed by chalcone synthase (SbCHS) converting p-coumaroyl CoA and malonyl CoA into naringenin chalcone (Fig. 2), followed by isomerization to the flavanone naringenin by chalcone isomerase. It is from naringenin that the anthocyanidin and 3-deoxyanthocyanidin pathways are believed to diverge from each other (Fig. 2). The biosynthesis of anthocya nin is one of the best characterized secondary metabolic pathways in plants. Flavanone-3-hydroxylase (SbF3H) catalyzes the C-3 hydroxylation of naringenin, followed by an NADPH-dependent reduction of the C-4 carbonyl group by dihydroflavonol 4-reductase (DFR). Removal of the resulting hydroxyl group then occurs via the anthocyanidin synthase (ANS)-catalyzed reaction. In sorghum, fungal inoculation was shown to result in de novo synthesis of 3-deoxyanthocyanidins. For example, infected seedlings incorporated 14C-phenylalanine into 3-deoxyanthocyanidins within 48 h post inoculation (5). In addition, activities of the key branch-point enzymes PAL and CHS and the expressions of their respective genes were induced within 6 h of inoculation (6, 7). In our recent RGC-GRF project, we were able to identify a pathogen-inducible sorghum DFR gene (SbDFR3) and demonstrated that it encodes an enzyme with flavanon e reductase activity (Fig. 2) (manuscript in preparation). Thus, naringenin and eriodictyol are converted to the respective flavan-4-ols, the presumptive immediate precursors for 3-deoxyanthocyanidin formation (Fig. 2). On the other hand, the molecular components responsible for the conversion of flavan-4-ols to 3-deoxyanthocyan indin are still unidentified. This dehydroxylation step has been suggested to be catalyzed by an ANS enzyme similar to the one involved in anthocyanidin formation. Our recent analysis of sorghum genome revealed the presence of a single ANS-encoding gene (SbANS). However, its expression is only activated during light-induced anthocyanin pigmentation, but not during pathogen-indu ced 3-deoxyanthocyanidin biosynthesis. Apparently, an independent gene encoding similar enzyme activities is likely to be responsive to pathogen infection for the phytoalexin production. Two major classes of transcription factors, the bHLH-type R/B family and the MYB-type C1 family, are known to regulate anthocyanin biosynthesis in many plants (8). On the other hand, P is a MYB regulatory protein acting independently of R1 and C1 in maize floral tissues for the accumulation of 3-deoxyflavonoids, including 3-deoxyanthocyanidins (9-11). In sorghum, there have been few studies on the regulation of flavonoid biosynthesis. Recently, the Myb gene Y1 was reported to encode a sorghum P homolog which determines 3-deoxyanthocyanidin pigmentation in the pericarp (12). The sorghum cultivar BTx623, which was found to harbor a deletion allele of Y1, produces seeds without the accumulation of 3-deoxyanthocyanid ins (13). However, infected BTx623 plants are still able to synthesize the 3-deoxyanthocyandin phytoalexins (14), strongly suggesting that a different regulatory network is involved for the pathogen-inducible biosynthesis of 3-deoxyanthocyanidins. Over the past decade, sorghum has become a subject of plant genomics research due to its importance as a major grain crop with unusual tolerance of dry and hot environments, a biofuel crop of high and growing significance, a progenitor of the world’s most noxious weeds, and a small genome model system for many highly photosynthetic-efficient C4 cereals with complex genomes. The genome sequencing of a leading US inbred, BTx623, is now complete, providing a foundation for the discovery of beneficial genes useful for different agricultural applications (15). In this study, we will take advantage of the sorghum genomic resource to facilitate our ongoing efforts to identify novel molecular components involved in the pathogen-inducible 3-deoxyanthocyanidin biosynthesis pathway. To identify the potential candidates for the final reaction step, bioinformatics analyses will be performed to retrieve ANS-homologous sequences for gene expression analysis using our sorghum inoculation system. In addition, we will use our recently implemented iTRAQ quantitative proteomics technology to investigate the differential protein expression profiles of sorghum cultivars with and without the ability to synthesize the 3-deoxanthocyanidin phytoalexins. It is expected that the phytoalexin-deficient line is defective in some key proteins, potentially enzymes and/or regulatory proteins, required for the biosynthesis pathway. Fina lly, we will employ our well-developed LC-MS/MS platform to examine the differential metabolite profiles of the two sorghum cultivars mentioned above. As the phytoalexin-deficient cultivar is likely to accumulate some intermediates of the 3-deoxyanthocyanidin pathway, their identification will further facilitate our searches for the unknown enzymes/genes along the pathway.


List of Research Outputs

Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen- inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Du Y. and Lo C.S.C. , Molecular characterizatiom of a flavone synthase gene in sorghum, Plant Biology 2009, Honolulu, Hawaii . 2009.
Li L. , Chu H. , Liu H. and Lo C.S.C. , Isolation and analysis of defense-related genes in infected sorghum seedlings, Plant Biology 2009, Honolulu, Hawaii . 2009.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxy anthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Liu H. , Lau E. , Lam P.Y. , Chu H. , Li S., Huang G., Guo P., Wang J., Jiang L., Chu I.K. , Lo C.S.C. and Tao Y., OsNOA1/RIF1 is a functional homolog of AtNOA1/RIF1: implication for a highly conserved plant cGTPase essential for chloroplast function., New Phytologist . 2010, 187: 83-105.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.
Lo C.S.C. , Senior Editor, Physiological and Molecular Plant Pathology . Elsevier, 2010.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.


Researcher : Lui WY

Project Title: Function of CLMP in rat testis and its regulation
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
The BTB situated between adjacent Sertoli cells physically divides the seminferous epithelium into the basal and adluminal compartments. The BTB not only maintains cell polarity, it also segregates the post-meiotic germ cell development from the systemic circulation to avoid autoimmune response [1, 3]. However, this intact barrier must disassemble at stage VIII of the seminiferous cycle to allow pre-leptotene and leptotene spermatocytes residing outside the BTB (the basal co mpartment) to migrate across the barrier and enter the adluminal compartment. Recent studies have indicated that Coxsackie and Adenovirus Receptor-Like Membrane Protein (CLMP) is a novel member of the Cortical Thymocyte Marker in Xenopus (CTX) family and a new component of epithe lial tight junction [6]. Exogenously expressed CLMP in polarized MDCK cells has shown that CLMP is restricted to the cell-cell interface and co-localized with ZO-1, a tight junction marker [6]. A significant increase in transepith elial electrical resistance (TER) has been found in cultured CLMP-expressing MDCK cells when compared to cells not expressing CLMP. CLMP has been found to associate with occludin in caco-2 cells and forced expression of CLMP in CHO cells induces cell aggregation [6]. Our recent findings have showed that testis expresses CLMP and CLMP is co-localized with occludin at the BTB [2]. We have also studied the transcriptional regulation of CLMP in Sertoli cells. It has noted that the expression of CLMP is mediated via the interaction of GATA and the Kruppel family proteins, KLF4 and Sp1. Moreover, our preliminary data showed that CLMP could be down-regulated by tumor necrosis factor alpha (TNF-alpha) via alterati on of its mRNA turnover. In our laboratory in the past years, a series of in vitro and in vivo studies have clearly demonstrated that TNF alpha and TGF-beta3 are key cytokines that perturb BTB and exerts potent negative effect in the expression of several TJ proteins in the testis such as JAM-A, CAR and occludin [1, 4, 5, 7]. These results taken together suggest that CLMP is a novel TJ protein that is regulated by TNF alpha and TGF-beta and is also involved in BTB dynamics. The P.I. seeks to characterize the role of Coxsackie and Adenovirus Receptor-Like Membrane Protein (CLMP) in the testis. Specifically, the P.I. will unravel (i) the functional role of CLMP in the testis and (ii) the effects of germ cells, cytokines (TNF-alpha and TGF-beta 3) and hormones (FSH and testosterone) on the expression of CLMP in Sertoli cells and in the testis. 1. Lui WY* and Cheng CY* (2007) Regulation of cell junction dynamics by cytokines in the testis – a molecular and biochemical perspective. Cytokine and Growth Factor Reviews 18:299-311 *Corresponding authors 2. Sze KL, Lee WM, Lui WY* (2007) Expression of CLMP, a novel tight junction protein, is mediated via the interaction of GATA with the Kruppel Family proteins, KLF4 and Sp1, in mouse testis. Journal of Cellular Physiology (in press) 3. Lui WY and Lee WM (2006) Regulation of junction dynamics in the testis – Transcriptional and post-translational regulations of cell junction proteins. Molecular and Cellular En docrinology 250:25-35 4. Li MW, Xia W, Mruk D, Wang CQ, Yan HH, Siu MK, Lui WY, Lee WM, Cheng CY (2006) Tumor necrosis factor alpha reversibly disrupts the blood-testis barrier and impairs Sertoli-germ cell adhesion in the semini ferous epithelium of adult rat testis. Journal of Endocrinology 190:313-329 5. Wong CH, Mruk DD, Lui WY, Cheng CY (2004) Regulation of the blood-testis barrier dynamics in the testis: an in vivo study. Journal of Cell Science 117:783-798 6. Raschperger E, Engstrom U, Pettersson RF, Fuxe J (2004) CLMP, a novel member of the CTX family and a new component of epithelial tight junctions. Journal of Biological Chemistry 279:796-804 7. Lui WY, Wong CH, Mruk DD, Cheng CY (2003) TGF-beta 3 regulates the blood-testis barrier dynamics via the p38 mitogen activated protein (MAP) kinase pathway: An in vivo study. Endocrinology 144:1139-1142


Project Title: Unraveling the mechanisms on cytokine-mediated regulation of Junctional Adhesion Molecules (JAM) in the testis
Investigator(s): Lui WY, Lee WWM
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Abstract:
(1) Identification of the signaling pathway(s) in cytokine-mediated transcriptional regulation of JAMs in testicular cells; (2) Characterization of the cytokine-mediated post-transcriptional regulation of JAM transcripts; (3) Characterization of cytokine-mediated post-translational modification of JAM proteins.


Project Title: Role of nectin-like molecules (necls) and its regulation in the testis
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2009
Abstract:
Background: Importance of junction restructuring in spermatogenesis Dynamic restructuring of adherens junctions (AJ) between Sertoli and germ cells is a crucial event for germ cell development. Migration of developing germ cells across the seminiferous epithelium requires timely disassembly and reassembly of AJs, so that germ cells are able to migrate towards the tubular lumen for further development, and at the same time they must remain physically attach onto Sertoli cells for nutritional and structural supports. The timely disassembly of AJs between Sertoli cells and mature spermatids is also important to allow the release of spermatozoa at spermiation. Any interruption of AJ restructuring could either lead to premature release of germ cells or blockage of germ cell migration along the epithelium, resulting in infertility. Therefore, it is apparent that precise control of AJ restructuring in the epithelium is crucial for the completion of germ cell development (1, 2). Biology and structural components of adherens junctions in the epithelium Actin-based cell-cell AJs are extensively localiz ed at the Sertoli cell/germ cell interface and between adjacent Sertoli cells. Ectoplasmic specialization (ES) is a testis-specific AJ, namely basal ES and apical ES. Basal ES is limited to adjacent Sertoli cells at the blood-testis barrier while apical ES is restricted to Sertoli cells and elongating spermatids (step 8 and beyond). Basal ES is constituted by several AJ proteins such as cadherin, nectin-2, Junctional Adhesion Molecule-B (JAM-B). However, four specific interlocking protein complexes, namely nectin-2/nectin-3, β1-integrin/laminin, JAM-B/JAM-C and nectin-like molecule 2 (necl-2)/necl-5 interlocks, are found at the apical ES (for review, see 2). These multiple interactions of junction proteins in the seminiferous epithelium ensure a close interaction of Sertoli and germ cells, and avoid detachment of premature germ cells from Sertoli cells during translocation. Nectin-like molecules (necls) and its members in the testis Nectin-like molecules are immunoglobulin (Ig)-like adhesion molecule that has three extracellular Ig domains, one transmembrane domain and a cytoplasmic tail containing a type II PDZ-binding domain. The necl family comprises five members and they are ubiquitously expressed. Like nectins, necls mediates both homophilic and heterophilic cell adhesion in Ca2+-independent manner (3). Other than its function on cell-cell adhesion, recent studies have shown that necls are involved in other cellular activities, including cell polarization, differentiat ion, movement and survival (4, 5). Three necl members (necl-2, -3, -5) are expressed in the testis (6-8). In the mouse testis, necl-2 is expressed exclusively on germ cells (6). Necl-2 is found in spermatogenic cells from intermediate spermatogonia to pachytene spermatocytes and steps 7-16 spermatids (6). Necl-2-based cell adhesion is found to be essential for retaining spermatocytes and elongating spermatids in the Sertoli cells for their maturation and the translocation of mature spermatids to the adluminal surface for release since three separate gene knockout studies have shown that male mice lacking necl-2 are infertile (6, 9, 10). Recent studies have shown that necl-2 can form a ternary complex with JAM-C via interaction with PAR3 in elongating and elongated spermatids (7). For necl-5, it is expressed in Sertoli cells. Co-immprecipitation studies have been shown that necl-5 is an interacting partner of necl-2 (11), suggesting that necl-2/necl-5 protein complex is one of the essential interlocking protein complexes to mediate the interaction between spermatogenic cells and Sertoli cells for germ cell development. For necl-3, a high level of necl-3 mRNA was detected in the testis. However, the localization and its function in the testis remain enigmatic (8). Cytokines and junction restructuring There are accumulating evidences showing that TGF-βs (TGF-β2 and TGF-β3) and TNFα are actively involved in junction restructuring in the seminiferous epithelium, thus facilitating the movement of developing germ cells. TGF-β3 is a crucial cytokine that modulates the disassembly of blood-testis barrier (constituted by basal ES and tight junctions), apical ES and AJ by down-regulating the expression of integral membrane proteins such as occludin and N-cadherin via the activation of different signaling pathways such as p38 and ERK pathways (12-15). Studies from our laboratory have demonstrated that TGF-β2 reduces JAM-B protein level. TGF-β2 exerts its negative regulatory effects on JAM-B via activating Smad proteins. Activate d Smads compete against and displace Sp1 proteins from the TGIF motif of JAM-B promoter, resulting in JAM-B repression (16). A recent study has shown that TGF-β2 accelerates the internalization of integral membrane proteins such as JAM-A and occludin via clathrin-coated pit and targets them into late endosomes for degradation by lysosomes, thereby reducing the level of proteins and leading to the disassembly of cell junctions (17) . Apart from TGF-β, TNFα is also a potent cytokine in regulating junction restructuring. TNFα can downregulate occludin, ZO-1, CLMP protein levels in the testis (18). We have demonstrated that TNFα acts on the CLMP mRNA transcript and destabilize the transcript by promoting the binding of tristetraprolin (TTP) at the 3’UTR region under the activation of JNK pathway (19). Besides, TNFα is capable to induce the disorganization of actin bundles and the cisternae of ER at the apical ES, leading to the release of premature spermatids (18). Objectives: This proposal aims to investigate the role of necls and its regulation in the testis. 1. To identify the interacting partners of necls in the testis 2. To investigate the effects of cytokines on the expression of necls in the testis 3. To identify the localization of necl-3 in the testis References: 1. Lui WY, Mruk D, Lee WM, Cheng CY (2003) J Androl 24:1-14 2. Lui WY and Cheng CY (2007) Cytokine and Growth Factor Reviews 18:299-311 3. Fujita E, Soyama A, Momoi T (2003) Exp Cell Res 2003 287:57-66 4. Takai Y, Irie K, Shimizu K, Sakisaks T, Ikeda W (2003) Cancer Sci 94:655-667 5. Takai Y, Miyoshi, Ikeda W, Ogita H (2008) Nat Rev 9:603-615 6. Fujita E, Kouroku Y, Ozeki S, Tanabe Y, Toyama Y, et al. (2006) Mol Cell Biol 26:718-726 7. Fujita E, Tanabe Y, Hirose T, Aurrand-Lions M, Kasahara T, et al. (2007) Am J Pathol 171:1800-1810 8. Pellissier F, Gerber A, Bauer C, Ballivet M, Ossipow V (2007) BMC Neurosci 8:90-107 9. van der Weyden L, Arends MJ, Chausiaux OE, Ellis PJ, et al. (2006) Mol Cell Biol 26:3595-3609 10. Yamada D, Yoshida M, Williams YN, Fukami T, Kikuchi S, et al. (2006) Mol Cell Biol 26:3610-3624 11. Wakayama T, Sai Y, Ito A, Kato Y, Kurobo M, et al. (2007) Biol Reprod 76:1081-1090 12. Lui WY, Lee WM, Cheng CY (2001) Endocrinology 142:1865-1877 13. Lui WY, Lee WM, Cheng CY (2003) Biol Reprod 68:1597-1612 14. Xia W, Cheng CY (2005) Dev Biol 280:321-43 15. Xia W, Mruk DD, Lee WM, Cheng CY (2006) J Biol Chem 281:16799-813 16. Wang Y and Lui WY (2008) Endocrinology (accepted) 17. Yan HH, Mruk DD, Lee WM, Cheng CY. (2008) FASEB J 22:1945-1959 18. Li MW, Xia W, Mruk D, Wang CQ, et al. (2006) J Endocrinol 190:313-329 19. Sze KL, Lui WY, Lee WM (2008) Biochem J 410:575-583


Project Title: 34th FEBS Congress Itch interacts with the pre-initiation complex for gene transcription
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Outstanding Young Researcher Award 2008-2009
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Young Researcher Award
Start Date: 12/2009
Abstract:
The Awards are intended to recognize, reward, and promote exceptional research accomplishments of academic and research staff.


Project Title: Coxsackie and adenovirus receptor-like membrane protein (CLMP) is a new tight junction protein in the testis: its role and regulations
Investigator(s): Lui WY, Lee WWM
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To investigate the role of CLMP in BTB dynamic s; 2) To identify CLMP-associating partners in the cytosol; 3) To assess the effect of cytokine on the expression of CLMP in Sertoli cells and in the testis.


Project Title: Unraveling the role of Ets related molecule (ERM) in the testis
Investigator(s): Lui WY
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
Background: Cell junctions in the seminiferous epithelium and their physiological significance in spermatogenesis Different types of cell junctions are found in the seminiferous epithelium. Apart from the tight junctions (TJ) that is localized at the blood-test is barrier (BTB), anchoring junctions are also found at the BTB and the Sertoli-germ cell interface in the seminiferous epithelium (1). These junctions are adherens junctions (AJ) including basal and apical ectoplasmic specializations (ES). ES is an actin-based testis-specific hybrid AJ type which is confined to the region between the plasma membrane of two adjacent Sertoli cells. Basal ES is limited to the BTB, coexisting with TJ, whereas apical ES is found between Sertoli cells and elongating/elongated spermatids (step 8 and beyond in adult rat testes). Knockout studies have shown that various TJ proteins including occludin, junctional adhesion molecule-A (JAM-A) claudin-11 and ZO-2 are essential for spermatogenesis. Knockout of these TJ proteins result in male infertility (2-4). Like TJ proteins, knockout of AJ proteins such as nectin-2, nectin-3 or JAM-C in mice cause severe disruption in spermatogenesis and all male mice are sterile (5-7). These results apparently illustrated the functional significance of junction proteins in spermatogenesis. Formation of the intact BTB between adjacent Sertoli cells and dynamic restructuring of cell junc tions (such as ES) between Sertoli and germ cells are crucial events for germ cell development (1). The formation of the BTB allows physical segregation of meiotic germ cells from the systemic circulation that avoids autoimmune response. During spermatogenesis, developing germ cel ls must migrate across the seminiferous epithelium towards the tubular lumen for further development, and at the same time they must remain physically attach onto Sertoli cells for nutritional and structural supports, such movement requires precise disassembly and reassembly of cell junctions. In addition, the timely disassembly of ES between Sertoli cells and mature spermatids is also important to allow the release of spermatozoa at spermiation (1). Any interruption of junction restructuring could either lead to premature release of germ cells or blockage of germ cell migration along the epithelium, resulting in infertility. Therefore, it is apparent that the formation of the BTB and timely junction restr ucturing in the epithelium are crucial for the completion of germ cell development. Infertility in male Ets related molecule (ERM) knockout mice Male mice with targeted disruption of Ets related molecule (ERM) displayed testicular atrophy with tubules devoid of germ cells (8). Although ERM is a transcription factor exclusively expressed in Sertoli cells, changes in gene expression levels are not restricted to Sertoli cells. In fact, a plethora of genes in spermatogonial germ cells are found to be altered in their expressions in the knockout mice (8). It is believed that knockout of ERM alters the gene expression in Sertoli cells, which results in significant change in seminiferous epithelial micr oenvironment and halts germ cell development. A list of genes in Sertoli cells has been found to be down-regulated (9- to 25-fold reduction) in ERM knockout mice and they are stromal cell-derived factor (SDF-1), chemokine ligand 5 (CXCL5), chemokine ligand 7 (CCL7) and matri x metalloproteinase 12 (MMP-12) (8). Based on the studies from other epithelial cells, it is known that chemokines and MMPs are crucial molecules that regulate the barrier function. For instance, chemokine, CCL2 induces TJ disassembly in blood-brain barrier by inducing internaliza tion of claudin and occludin (9), whereas MMP promotes extracellular matrix degradation and resulting in junction disruption (10). However, it remains unknown whether the knockout of ERM gene affects the integrity of the blood-testis barrier and cell junction restructuring in the testis and whether ERM acts directly to control the gene transcription of junction proteins. Regulation of junction dynamics via transcriptional and post-translational modifications Timely regulation of the expression of different junction proteins in the testis is crucial during spermatogenesis. Both transcriptional and post-translational modifications are major approaches to exhibit temporal and spatial expression of junction proteins in the testis (1, 11). Studies from our laboratory have demonstrated that cytokine exerts its negative regulatory effects on JAM-B transcription via activating Smad proteins (12). Activated Smads compete against and displace Sp1 proteins from the TGIF motif of JAM-B promoter, resulting in JAM-B repression. A recent study has shown that cyto kine trigger the internalization of integral membrane proteins such as JAM-A and occludin via clathrin-coated pit and targets them into late endosomes for degradation by lysosomes (13), thereby reducing the level of proteins and leading to the disassembly of the BTB. Objectives: This proposal aims to investigate the role of ERM on junction restructuring in the testis 1. To generate two Sertoli cell cell lines, (1) stably-expressing ERM in TM4 cells; and (2) stably-expressing ERM shRNA in MSC-1 cells 2. To assess the effect of ERM on the expression of junction proteins Reference: 1. Lui WY and Cheng CY (2007) Cytokine and Growth Factor Reviews 18:299-311 2. Saitou M, Furuse M, Sasaki H, Schulzke JD, Fromm M, Takano H, Noda T and Tsukita S (2000) Mol Biol Cell 11:4131-414 2 3. Xu J, Anuar F, Ali SM, Ng MY, Phua DC and Hunziker W (2009) Mol Biol Cell 20:4268-4277 4. Gow A, Southwood CM, Li JS, Pariali M, Riordan GP, Brodie SE, Danias J, Bronstein JM, Kachar B and Lazzarini RA (1999) Cell 99:649-659 5. Mueller S, Rosenquist TA, Takai Y, Bronson RA and Wimmer E (2003) Biol Reprod 69:1330-1340 6. Ozaki-Kuroda K, Nakanishi H, Ohta H, Tanaka H, Kurih ara H, Mueller S, Irie K, Ikeda W, Sakai T, Wimmer E, Nishimune Y and Takai Y (2002) Curr Biol 12:1145-1150 7. Gliki G, Ebnet K, Aurrand-Lions M, Imhof BA and Adams RH (2004) Nature 431:320-324 8. Chen C, Ouyang W, Grigura V, Zhou Q, Carnes K, Lim H, Zhao GQ, Arber S, Kurpios N, Murphy TL, Cheng AM, Hassell JA, Chandrashekar V, Hofmann MC, Hess RA and Murphy KM (2005) Nature 436:1030-1034 9. Stamatovic SM, Keep RF, Wang MM, Jankovic I and Andjelkovic AV (2009) J Biol Chem 284:19053-19066 10. Klessner JL, Desai BV, Amargo EV, Getsios S and Green KJ (200 9) Mol Biol Cell 20:328-337 11. Lui WY and Lee WM (2008) Front Biosci 13:6775-6786 12. Wang Y and Lui WY (2009) Endocrinology 150:2404-2012 13. Yan HH, Mruk DD, Lee WM and Cheng CY. (2008) FASEB J 22:1945-1959


List of Research Outputs

Lee W.W.M. , Leung T.K. and Lui W.Y. , Interferon- g and tumor necrosis factor a downregulate the expression of junctional adhesion molecule-C (JAM-C) through transcriptional and post-translational controls , The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Lui W.Y. , Editorial Board Member, Spermatogenesis . 2010.
Lui W.Y. , HKU Outstanding Young Researcher Award, The University of Hong Kong . 2010.
Lui W.Y. and Tam C.Y. , Itch interacts with the pre-initiation complex for gene transcription, The 34th Federation of European Biochemical Societies (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.
Lui W.Y. and Lee W.W.M. , Molecular mechanisms by which hormones and cytokines regulate cell junction dynamics in the testis, Journal of Molecular Endocrinology . 2009, 43: 43-51.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness, The 35th FEBS Congress Molecules of LIfe. June 26- July 1, 2010. . 2010.


Researcher : Ma CY

Project Title: Analysis of chemically modified non-starch polysaccharides by Raman spectroscopy
Investigator(s): Ma CY
Department: Botany
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To apply the technique of Raman spectroscopy for determining degrees of chemical modification in proteins, and extend the technique to study modified non-starch polysaccharides.


Project Title: Institute of Food Technologists Annual Conference 2009 Conformational study of SPI treated with ultrasound
Investigator(s): Ma CY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2009
Abstract:
N/A


Project Title: 15th European Carbohydrate Sympos ium (eurocarb 15) Raman and FTIR spectroscopic study of sulfated non-starch polysaccharides
Investigator(s): Ma CY
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A




Researcher : Ma J

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J. , Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.


Researcher : Ma J

List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J. , Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J. , Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.


Researcher : Mruk DD

List of Research Outputs

Cheng C.Y. , Wong E.W.P. , Yan H.H.N. and Mruk D.D. , Regulation of spermatogenesis in the microenvironment of the seminiferous epithelium: new insights and advances, Mol Cell Endocrinol . 2010, 315: 49-56.
Li W.M.M. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Disruption of the blood-testis barrier integrity by bisphenol A in vitro: Is this a suitable model for studying blood-testis barrier dynamics? , International Journal of Biochemistry & Cell Biolo gy. . 2009, 41: 2302-2314.
Lie P.Y.P. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Cytoskeletal dynamics and spermatogenesis. , Philos Trans R Soc B . 2010, 365: 1581-1592.
Lie P.Y.P. , Chan A.Y.N., Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Restricted Arp3 expression in the testis prevents blood-testi s barrier disruption during junction restructuring at spermatogenesis. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11411-11416.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Ng CY

List of Research Outputs

Arrigoni JR J.E. , Dudgeon D. , Lee P.P. and Ng C.Y. , Development of a Method for Biological Monitoring of Hong Kong Rivers and Streams (Tender Ref. WP 07-039): Final Report, Prepared for the Environmental Protection Department, Hong Kong SAR Government . 2009, 1-101.


Researcher : Ng SM

Project Title: Molecular cloning and functional characterization of the human cell cycle related kinase-interacting proteins
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Small Project Funding
Start Date: 12/2005
Abstract:
1. To clone the genes encoding the proteins that specifically interact with CCRK in a yeast two-hybrid screening. 2. To elucidate the functional roles of the CCRK-interacting proteins in glioblastoma carcinogenesis.


Project Title: The role of chemokine CC-motif receptor-like 2 (CCRL2) in colon cancer carcinogenesis
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2008
Abstract:
Colorectal cancer or colon cancer is the third most common cancer worldwide and it ranks only after breast and lung cancers in females, and prostate and lung cancers in males (Jemal et al., 2004). In Hong Kong, the incidence of CRC is increasing rapidly and it has become the second most common cancer with more than 3,500 new patients diagnosed every year (Hong Kong Cancer Registry, 2004). Compared with other parts of the world, Hong Kong has more colon cancer patients under 40 years old (Yuen et al., 1997). Therefore, understanding the pathogenesis of colon cancer and identifying new molecular targets are critical for establishing novel therapeutic and diagnostic strategies against this potentially fatal disease. It has been estimated up to 20% of colon cancer cases are resulting from chronic intestinal inflammation. This is supported by the findings that inflammatory bowel diseases (IBD) like ulcerative colitis and Crohn’s disease, markedly increase the risk of colon cancer (Klamfer, 2008). Recently, it has been demonstrated that signals which promote inflammation like, nitric oxide (Ying et al., 2007), interleukin 22 (Ziesche et al., 2007), and STAT 3 (Klampfer, 2008) are upregulated in colon cancer cells. Moreover, Kim et al. showed that expression of CXCR4, a well-characterized chemokine receptor for T cells, is associated with reduced overall survival and increased risk for recurrence and liver metastasis in colon cancer patients (Kim et al., 2005). Therefore, there is inc reasing evidence that chemokine receptors, which transduce signals for inflammation or the recruitment of immune effector cells, may initiate the carcinogenesis of colon cancer. Chemokines are small proteins (~ 8-10 kD) that regulate cell migration. Cells that are attracted by chemokines follow a signal of increasing chemokine concentration towards the source. Currently, there are more than 50 known chemokines and 18 chemoki ne receptors which play crucial roles in many important cellular functions including leukocyte recruitment, angiogenesis, and inflammation (Proudfoot et al., 2002). Chemokine CC-motif receptor-like 2 (CCRL2) (also known as human chemokine receptor (HCR), CRAM, or CKRX) is a putative 7-transmembrane G protein-coupled chemokine receptor (Neote et al., 1993; Fan et al., 1998). The CCRL2 gene is located on chromosome 3p21, a locus within the main cluster of CC-chemokine receptor genes (Maho et al., 1999). The CCRL2 receptor was first isolated in a polymorphonuclear neutrophil (PMN) cDNA library (Fan et al., 1998) and is expressed on virtually all hemopoietic cells such as monocytes, T cells, dentritic cells, natural killer cells, and CD34+ progenitor cell s (Patel et al., 2001; Migeotte et al., 2002), suggesting that this receptor is instrumental for cell-mediated immune responses and local inflammation. However, the role of CCRL2 in human cancers has never been elucidated. The objective of this project is to explore the potential role of CCRL2 in colon cancer carcinogenesis. We have obtained 12 local colon cancer tissue samples and their adjacent normal tissues and analyzed the expression profiles of CCRL2 using semi-quantitative RT-PCR. We found that CCRL2 mRNA expression was elevated in 6 out of 12 (50%) of colon cancer tissues by more than 1.5-fold (Fig. 1A, B). Moreover, expression of CCRL2 was also detected in both LoVo and DLD1 human colon cancer cell lines (Fig. 1C). Therefore, we hypothesized that overexpression of CCRL2 may induce chronic intestinal inflammation and subsequently initiate carcinogenesis in colon cancer patients. Results obtained from this study will provide new insights on the role of this chemokine receptor in colon cancer carcinogenesis.


Project Title: Identification and characterization of chemotherapeutic drugs targeting cancer stem cells
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Abstract:
Cancer cells within a tumor population often exhibit distinct proliferative and differentiation capacities, a phenomenon known as tumor heterogeneity. Early studies of spontaneous mouse leukaemias and lymphomas showed that the frequency of tumor-propagating cells ranged from 1% to 80-90% of the cells (Hewitt, 1958; Hamburger and Salmon, 1977). The mechanisms underlying tumor heterogeneity remain elusive, but at least two models have been put forward to explain the differences in the growing and regenerating capacities observed in cancer, namely the clonal evolution model (Nowell, 1976) and cancer stem cell model (Campbell, 2007). In the clonal evolution model, all undifferentiated cells have similar tumorigenicity and a dominant population of proliferating cells drives tumorigenesis. By contrast, the cancer stem cell model proposes that a subset of cancer cells, referred to as cancer stem cells, is responsible for sustaining tumor growth. Cancer stem cells are considered as a distinct group of ste m cells because they share important characteristics with normal stem cells. They have the abilities of self-renewal, generating additional cancer stem cells, and differentiating into phenotypically diverse cancer cells with lower proliferative potential. Cancer stem cells have been characterized in human acute myeloid leukaemia, breast cancer and brain cancer and surface markers have been identified in these cancer types. For example, in human breast cancer, cancer stem cells were found to express CD44 but little or no CD24 (CD44 +CD24-/low) and have enriched tumor-initiating capacity; as few as 200 CD44+ CD24-/low cells were able consistently form tumors (Al-Hajj et al., 2003). In brain cancer, cancer stem cells were found to be those which express the human neural stem cell marker CD133 (CD133+), and they were accounted for almost all in vitro proliferat ive capacity (Singh et al., 2003). Collectively, these findings suggest that cancer stem cells play a crucial role in tumorigenesis and elimination of cancer stem cells is important for providing long-term disease-free survival in cancer patients. Eradication of cancer stem cells is still a major challenge for scientists mainly because they have stronger resistance to radiother apy and chemotherapy than ordinary cancer cells. This resistance may be attributed to better initiation of DNA damage response and overexpression of drug-resistance associated proteins within cancer stem cells (Pardal and Morrison , 2003). Because cancer stem cells lead to high tumorigenic potential and develop strong resistance to radio- and chemo-therapy, they may play a pivotal role in initiating the tumor recurrence. Thus, discovery of novel chemotherap eutic drugs which effectively or specifically target cancer stem cells are urgently needed. Gold-containing compounds have been shown to possess strong anti-tumor activities (Cagnoli et al., 1998; Marcon et al., 2002). However, compound containing gold in the +III oxidation state tend to be reduced in vivo to gold(I) and metal lic gold as the intracellular environment is generally reducing (Tiekink, 2002). In collaboration with Prof. C. M. Che at the Department of Chemistry, we have recently synthesized a series of gold(III) meso-tetraporphyrins that are stable at physiological conditions (Che et al., 2003). The porphyrins ligands in these compounds stabilize the gold(III) center and carry it to their cellular targets. Their cytotoxicity is approximatel y 100-fold higher than that of cisplatin, a commonly used chemotherapeutic drug, in several human cancer cell lines (Che et al., 2003). Among these gold-containing compounds, we have previously demonstrated that gold (III) meso-tetraarylporphyrin 1a (gold-1a) exhibits strong anti-tumor activity in hepatocellular carcinoma (HCC) (Lum et al., 2006). We also tested the anti-tumo r effect of gold-1a in other cancer types including nasopharyngeal carcinoma (NPC) and melanoma. In agreement with the findings in HCC, gold-1a also exhibits potent cancer-killing , anti-metastatic, and antiangiogenic actions in mice bearing NPC (Fig. 1). Therefore, we hypothesize that gold-1a may mediate its anti-cancer effects by targeting cancer stem cells and thereby significantly inhibiting tumor growth, angiogenesis, and metastasis. The primary goal of this project is to evaluate the chemocytotoxi c effects of gold-1a, the second-generation gold(III) meso-tetraarylporphyrins (synthesized based on the structure of gold-1a), and other chemotherapeutic drugs (e.g. cisplatin and dacarbazine) on cancer stem cells. We will use the human NPC C666-1 cell line and human melanoma B16 cell line as our cell models because we have already shown previously that gold-1a potently inhibits the growth and/or metastasis of C666-1 cells and B16 cells in vivo (Fig. 1). The specific aims of this project are: 1. To examine the effects of gold-1a, the second generation gold-1a, and other chemotherapeutic drugs on the expression of common stem cell markers in human NPC C666-1 and human melanoma B16 cell lines. 2. To determine the cytotoxic effects of gold-1a, the second-generation gold-1a, and other chemotherapeutic drugs on the cancer stem cells in vitro. References: Please refer to Section VII.


Project Title: Development of novel nanopolymers for cancer gene therapy
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 03/2009
Abstract:
Gene therapy is being developed as an alternative means of medical intervention for cancer and a variety of disorders (reviewed in 1, and references therein). Viral and non-viral vectors are the two principal gene delivery methods for gene therapy. Although a number of viral vectors such as adenovirus (Adv), adeno-associated virus (AAV), and lentivirus have been proposed, there are still concerns about their safety, immunogencity, and efficacy for therapeutic applications in humans (reviewed in 2). Therefore, non-viral gene delivery systems, which are based upon polymer/DNA complexes, are attracting increasing attention owing to their ease of structural modifications and potential in avoiding the problems associated with viral vectors (reviewed in 3). An ideal polymer-based gene delivery vehicle should be bio-absorbable, non-toxic, non-immunogenic, stable, and able to access target cells after administration . Among several non-viral vectors that are currently in use, polyethylenimine (PEI), a polycationic copolymer, has shown good transfection efficiency both in vitro and in vivo (reviewed in 4). PEI has been used in a diversity of processes for many years. The basic unit of PEI consists of a backbone of two carbons followed by on e nitrogen atom. PEI comes in two forms: linear and branched. The branched form is produced by cationic copolymerization from ethylenimine (aziridine) monomers via a chain-growth mechanism, with the branched sites arising from specific interactions between two growing copolymer molecules. Depending on its molecular weight, structure and dosages, PEI can be toxic to certain cells (reviewed in 5-7). It has been reported that branched PEIs with a molecular weight (MW) of 25,000 or greater display relatively high cytotoxicity, possib ly because of the formation of large aggregates on the cell surface. Low molecular weight PEIs ( <1,800) show much less toxicity, but have very low transfection efficiency. Cyclodextrins (CyDs) are cyclic (alpha-1,4)-linked oligosaccharides of alpha-D- glucopyranose containing a hydrophobic central cavity and hydrophilic outer surface. The most common CyDs are alpha-, beta- and gamma-CyDs, which are composed of six, seven, and eight D-glucopyranose units, respectively. It has be en well documented that CyDs lack toxicity and immunogencity, and they are able to form inclusion complexes with a variety of guest molecules both in solution and in solid states. Although CyDs themselves are not effective gene carriers, they can act as a viral dispersant by enhancing both viral binding and internalization, result ing in an increase in adenoviral transduction in human colon adenocarcinoma Caco-2 cells. CyDs can disrupt biological membranes by forming complexes with phospholipids and cholesterols, which can assist the cellular uptake of polyamidoamine dendrimer/DNA particles and intracellula r trafficking of DNA molecules. The major limitations of viral vectors as tools for gene therapy are the biosafety concerns and difficulties in preparing sufficient quantities of the viruses for clinical trials and future clinical use. In order to overcome these drawbacks, our team is focusing on developing nanoplymer for gene delivery. We have already formed a collaboration with Prof. Guping Tang at Zhejiang University on the development of novel nanopolymers as gene delivery system for the treatment of glioblastoma and melanoma (selected refs. 8-14). Recently, we have jointly characterized one of the most promising nanopolymers which has high effic iency and low toxicity (patent and manuscript in preparation). This nanopolymer consists of beta-cyclodextrin (beta-CyD) as the cross-linker for connecting low molecular weight polyethylenimine (PEI). We have further improved th e gene targeting efficiency of beta-CyD-PEI by conjugating it with folic acid (CyD-PEI-FA) (Fig. 1). The resulting polymer has no detectable toxicity and exhibits high transduction efficiency comparable to that of leading commercial transfection reagents (Figs. 2 and 3). These findings have laid down a solid foundation for the further developing CyD-PEI-FA and other novel nano-bi opolymers. The purpose of this research is to develop novel and highly efficient nanopolymers as gene delivery systems for cancer gene therapy. The specific aims of this proje ct are: 1. To characterize the 3-dimensional structure, toxicity and the DNA binding affinity of CyD-PEI-FA / plasmid DNA complex in vitro in cell culture systems. 2. To determine the tumor targeting ability, tissue distribution , gene expression level, and toxicity of CyD-PEI-FA / plasmid DNA complex in vivo in mice. 3. To determine the therapeutic efficacy of CyD-PEI-FA / plasmid expressing interleukin 2 (pIL2) for the treament of melanoma in vivo in mice. References: 1. Curiel, DT.; Gerritsen, Winald R.; Krul, Mark R. L. Progress in cancer gene therapy. Cancer Gene Therapy (2000), 7(8), 1197-1199 . 2. El-Aneed, Anas. An overview of current delivery systems in cancer gene therapy. Journal of Controlled Release (2004), 94(1), 1-14. 3. Vasir, Jaspreet K.; Labhasetwar, Vinod. Polymeric nanoparticles for gene delivery. Expert Opinion on Drug Delivery (2006), 3(3), 325-344. 4. Lungwitz, U.; Breunig, M.; Blunk, T.; Goepferich, A. Polyethylenimine-based non-viral gene delivery systems. European Journal of Pharmaceutics and Biopharmaceutics (2005), 60(2), 247-266. 5. Pietersz, Geoffrey A.; Tang, Choon-Kit; Apostolopoulos, Vasso. Structure and design of polycationic carriers for gene delivery. Mini-Reviews in Medicinal Chemistry (2006), 6(12), 1285-1298. 6. Hunter, A. Christy. Molecular hurdles in polyfectin design and mechanistic background to polycation induced cytotoxicity. Advanced Drug De livery Reviews (2006), 58(14), 1523-1531. 7. Pack, Daniel W.; Hoffman, Allan S.; Pun, Suzie; Stayton, Patrick S. Design and development of polymers for gene delivery. Nature Reviews Drug Discovery (2005), 4(7), 581-593. 8. Shilei, Tang Guping, Gao Shujun, Ma Yuexia, Liu Beih ui, Li Ying, Zhen Jieming, Ng Yee Kong, Kam Leong and Shu Wang. Repeared intrathecal administration of plasmid DNA complexed with polyethylene glycol-grafted polyethlenimine for prolonged transgene expression in the spinal cord. Gene Therapy. 2003;10:1179-1188. 9. Tang GP, Zeng JM, Gao SJ, Ma YX, Shi L, Li Y, Too H-P and Wang S. Polyethyene glycol-grafted polyetylenimine for improved CNS gene transfer: Effects of PEGylation extent. Biomaterials. 2003;24:2351-236218. 10. Y Li, J Wang, C Lee, C Y Wang, S J Gao, G.P.Tang, Y X Ma, Boon Soon, C T Lim, H Yu, H Q Mao, KW Leong and S Wang CNS gene transfer facilitated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes. Gene Therapy. 2004;11:109-114 11. G.P.Tang, Z.Yang and J.Yan A. A new biodegradable poly-amino acid: α,β-poly[(N-hydrox ypropyl/aminoethyl)-DL-asppartami A potential non-viral vector for gene delivery. Drug Delivery. 2005;12:89-9. 12. Huanghong liang, Guping Tang, Qingqing Wang, Da Li, Two novel non-viral gene delivery vectors: low molecular weight polytheylenimine cross-linked by (2-hydroxypropyl)-b-cyclodextrin or (2-hydroxypropyl)-r-cyclodextrin. ChemComm. 2006:2382- 2384 13. GP Tang, HY Guo, F.Alexis, X Wang, S.Zeng, T.M.Lim, J.Ding, Y.Y.Yang, S Wang Low molecular weight polyethylenimine linked by b-cyclodextrin for gene transfer into the nervous system. The Journal of Gene Medicine. 2006;8(6):736-744 14. Da Li, Jingzhong Li, Qingqing Wang, Guping Tang, Hai Yu, Xuetao Cao. Combined targeting of polyethylenimine to FGF receptors and integrins on cells surface improves gene transfer efficiency. J. Biomater. Sci. Polymer Edn. 2007;18:545


Project Title: The role of CCRK as a novel CDK-activating kinase in human glioblastoma
Investigator(s): Ng SM, Lin MC
Department: Chemistry
Source(s) of Funding: General Research Fund (GRF)
Start Date: 07/2009
Abstract:
1) To identify proteins that associate with CCRK-cyclin H complex by co-immunoprecipitation and Tandem Affinity Purification (TAP); 2) To determine whether cyclin H and/or the interacting protein subunits are essentia l for the CAK activity of CCRK; 3) To examine if the CCRK-cyclin H holoenzyme complex is a bona fide cancer target.


List of Research Outputs

An X. , Ng S.M. , Xie D., Zeng Y.X., Sze J. , Wang J. , Chen Y.C., Chow B.K.C. , Lu G., Poon W.S., Kung H.F., Wong B.C.Y. and Lin M.C. , Functional characterisation of cell cycle-related kinase (CCRK) in colorectal cancer carcinogenesis. , European Journal of Cancer . 2010, 46: 1752-1761.


Researcher : Ng SS

List of Research Outputs

Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.


Researcher : Ng WC

List of Research Outputs

Lui K.Y. , Leung T.Y. , Ng W.C. and Leung K.M.Y. , Genetic variation of Oratosquilla oratoria (Crustacea : Stomatopoda) across Hong Kong waters elucidated by mitochondrial DNA control region sequences, Journal of the Marine Biological Association of the United Kingdom . 2010, 90: 623-631.
Ng W.C. , Leung T.Y. and Williams G.A. , Comparative proteomic responses in two intertidal limpets (Cellana grata and Cellana toreuma) to summer low tides on tropical rocky shores, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limpet Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology . July 7-10, 2009. Beijing, China . 2009.


Researcher : Ng YLS

List of Research Outputs

Ng Y.L.S. , Lee T.O. and Chow B.K.C. , Insights into evolution of proglucagon-derived peptides and receptors in fish and amphibians. , Ann N Y Acad Sci. . 2010, 1200: 15-32.
Ng Y.L.S. , Chow B.K.C. , Kasamatsu J., Kasahara M. and Lee T.O. , Molecular cloning and characterization of a VPAC receptor in the inshore hagfish, Eptatretus burgeri, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan . 2009.


Researcher : Pan Q

List of Research Outputs

Yan A. and Pan Q. , The N- and C- terminal regions of E. coli global transcription factor FNR participate in regulation of FNR protein levels, Molecular Genetics of Bacteria and Phages Meeting 2009, August 4-9, Madison, WI, USA . 2009.


Researcher : Pang CC

List of Research Outputs

Pang C.C. and Saunders R.M.K. , Floral phenology and breeding system of Desmos chinensis (Annonaceae): protogyny and intra-individual floral synchronicity to promote out-crossing, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.


Researcher : Park TJ

List of Research Outputs

Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydrogen peroxide, The 3rd International Symposium of Integrative Zool ogy, July 7-10, 2009. Beijing, China . 2009.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothion ein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollut ion and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Park TJ

List of Research Outputs

Leung T.Y. , Park T.J. , Wang Y. and Leung K.M.Y. , Proteomic profiling of metallothionein isoforms in the green-lipped mussel exposed to cadmium and hydro gen peroxide, The 3rd International Symposium of Integrative Zoology, July 7-10, 2009. Beijing, China . 2009.
Park T.J. , Leung T.Y. , Wang Y. and Leung K.M.Y. , Cloning and characterization of a novel metallothionein gene in the green lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Partanen HA

List of Research Outputs

Partanen H.A. , El-Nezamy H.S. , Leppanen J.M., Woodhouse H.J. and Vahakangas K.H., Aflatoxin B1 Transfer And Metabolism In Human Placenta, Toxicological Sciences . 2010, 113: 216-225.


Researcher : Peng X

List of Research Outputs

Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Peng X

List of Research Outputs

Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Pointing SB

Project Title: Development of an on-line platform for problem-based learning in the interdisciplinary science subject ‘Origins of Life and Astrobiology’
Investigator(s): Pointing SB, Kwok S
Department: Ecology & Biodiversity
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 06/2007
Abstract:
Objectives To develop an on-line platform (also with CD-ROM) for problem-based learning in the interdis ciplinary science subject ‘Origins of Life and Astrobiology’. Key issues and problems to be addressed The course ‘Origins of Life and Astrobiology’ is the most popular electiv e course by enrolment in the Faculty of Science (181 students in the last academic year), and enjoys extremely high SET scores for both teacher effectiveness (77.5%) and course effectiveness (76.2%). The success of this course’s appeal lies in its interdisciplinary nature: The subject matter involves an integrative learning experience incorporating concepts from biology, chemistr y and physics. In this way, by considering problems in understanding the conditions required for life to survive on early Earth and other planets, students develop a more integrative view of the sciences and learn in a ‘fun’ way by addressing problems relevant to a topical and exciting concept. The course is already supported by a website designed by the PI that delivers all lecture material, links to relevant websites and other ‘housekeeping’ functions such as examination and coursework instructions, teacher-student chat forum etc (access via www.hku/ecology/extremophiles). The next step in continued improvement and evolution of this popular course is to develop interactive on-line content and this is the purpose of this application. This is perceived as a need that will directly benefit students on courses with high enrolment. Students currently engage in problem-based project work in groups and this is necessitated by the high enrolment on the course and constraints on the teacher’s time. Providing students with the opportunity for problem-based learning on an individual basis is therefore highly desirable and would further enrich the overall learning experience provided by this course. To this end, funding is sought to produce on-line problem based learning tools relevant to astrobiology that students may work through individually and in their own time, and then obtain feedback from the courseware and teacher. The Faculty has clearly stated a desire to further develop teaching efforts in interdisciplinary areas such as astrobiology, and so this endeavour fits well with this vision. It wi ll benefit the maximum possible number of students and also has value in providing a basis for future development of similar courseware in other courses. The co-investigator at NASA will provide copyright-released imagery and data from current Mars exploration missions for parts of the courseware and this will add authenticity to the overall experience for the student.


Project Title: Microbial composition of urban aerosols in Hong Kong and implications for environmental quality and public health
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 11/2007
Abstract:
Purpose of the project: Determine the prokaryotic microbial composition of urban aerosols in Hong Kong, including identification of potentially harmful taxa, and establish the extent of pollution and climate related temporal variation. Key Issues and problems to be addressed: Why study aerobiology? Microorganisms are responsible for beneficial, benign and harmful effects to man and the environment, and a common featu re of most microorganisms is that they are transported in the air. The study of aerobiology is therefore of key importance in understanding the dispersal, ecology and evolution of microorganisms. With the recent regional emphasis on emergent diseases, public health in relation to air quality, indoor air quality, and dust storms (that transport and protect aerial microorganisms) related to environmental degradation, plus the increasing threat of bio-terrorism worldwide, it is timely that an inventory of Hong Kong’s microbial aerosol is proposed. Remarkably little is actually known about atmospheric microbial composition, and indeed there is no data on the atmospheric aerobiology of Hong Kong or any other regional city or rural area, despite some focus on indoor air quality (e.g. Sci Total Env 273: 27-40 ; and the unpublished work of the Indoor Air Quality Association [IAQA] that mainly focuses on fungal spores and pollen). The increasing awareness of climate change also adds necessity to the need for an understanding of Hong Kong’s aerobiology. Dust storms associated with climate-related environmental degradation are increasingly more common in China, and similar dust storms in Africa have been linked to increased transport of human pathogens such as Neisseria meningitidis (WHO , 2003), those causing environmental damage such as coral reef disease (Geophys Res Lett 27: 3029-3032), and illness from non-specific cause such as pediatric asthma (Int J Biometeorol 49: 371-376). What do we already know? Very little is known about atmospheric aerobiology. Early studies showed that culturable bacteria were concentrated in aerosols created by plant canopy and the sea surface (Appl Environ Microbiol 50: 1229-1232; Science 197: 763-764; J Aerosol Sci 36: 801-812). Viable Fungi and bacteria have also been characterized from high altitudes of up to 20,000m (Aerobiologia 20: 135-140). Recent work has focused upon dust storms in Africa and as these travel in the atmosphere across oceans (Aerobiologia 20: 99-110; Aerobiologia 21: 1-19; Aerobiologia 22: 211-226). These studies have demon strated inter-hemispheric dispersal and viability among a range of cultivable fungi and bacteria, with a clear positive correlation between dust loading in the atmosphere and microbial occurrence. A problem with these approaches is of course it is now widely accepted that cultivable microorganisms represent only a fraction (and also a very skewed fraction!) of total diversity. The relative ease and affordability of metagenomic approaches to community analysis are just starting to be applied to aerobiology. These have the advantage that by removing the need for cultivation a much more representative picture of community structure can be obtained. One study used ARISA to form community genetic fingerprin ts of two air samples from rural France (Atmos Environ 39: 3687-3695). Clone library analysis of 16S rRNA genes from one sample revealed a predominance of proteobacteria, in contradiction to earlier cultivation studies. Earlier this year the first comprehensive metagenomic analys is of aerobiology was published for urban aerosols in two US cities (Proc Natl Acad Sci USA 104: 299-304). This approach used a combination of microarray and clone libraries to establish an extremely biodiverse aerosol with diversity levels approaching those of soil. Importantly they also identified numerous pathogenic taxa including some relatives of bio-terrorism agents. This study proposed that temporal and meteorological factors were more likely to shape aerosol diversity than geographic location between two US cities. What are the research gaps and how can they be addressed? Key questions for further work are: 1. What is the microbial composition of urban aerosols in a tropical seasonal climate such as Hong Kong? 2. What anthropogenic (i.e. respirable suspended particles) and climatic variables are significant over an annual seasonal cycle? 3. Is there a significant risk from pathogens in Hong Kong’s urban aerosol? These questions are proposed to be addressed in the Objectives section of this research proposal. The PI has extensive experience and a proven publication track record in the field of resolving microbial community structure using metagenomic (envir onmental phylogenetic) approaches, including recent papers in the leading journal within the field of environmental microbiology (Environmental Microbiology, impact factor 4.6) plus several others in journals ranked within the top 25% of their field. Objectives: 1. Conduct a regular sampling of urban aerosols in Hong Kong over a 12-month period at several locations and apply metagenomic analysis of microbial community str ucture (in Objective 2). Also concomitantly to collect climatic data including temperature, RH, respirable suspended particles, wind speed and direction data from EPD weather stations. 2. Carry out a culture-independent molecular survey of community structure for all samples, using TRFLP of 16S rRNA genes, and then construct representative clone libraries to establish phylogenetic identity of taxa. To give particular focus to the identification of potentially pathogenic taxa and risk assessment. 3. Establish temporal pollution and climate related patterns in aerosol microbiology by conducting multivariate analysis with regard to abiotic variables.


Project Title: Metagenomic and proteomic analysis of microbial colonization, productivity and adaptation to moisture stress in Chinas deserts'
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2008
Abstract:
(1) Elucidate microbial community composition at the metagenomic level for lithic crusts on quartz from desert locations along a well-defined environmental gradient of moisture stress in China and other reference locations worldwide; (2) Determine the extent of net primary productivity by lithic crusts at different aridity-defined locations and under controlled labor atory conditions simulating various environmental conditions; (3) Examine the response to desiccation stress and re-wetting at the proteomic level for membrane and cytosolic components of selected crust taxa isolated from the most dry-adapted communities.


Project Title: Microbial ecology of lithic communities in Antarctica's Dry Valleys
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
The key objectives of the proposed study are: 1. Establish distribution on a landscape-scale for lithic microbia l colonization in the Antarctic Dry Valleys Special Protected Area. 2. Quantitatively determine overall community diversity and the metabolically active fraction of communities. 3. Elucidate the phylogenetic history of communities in order to understand their origins and dispersal, thus contributing to the broader issue of resolving microbial biogeography. 4. Determine the effect of abiotic variables on diversity using multivariate analyses, in order to understand the abi otic drivers of microbial diversity in cold polar desert ecosystems. Key issues and problems to be addressed: The Antarctic Dry Valleys are a unique and endangered hyper-a rid ecosystem that has been poorly studied - The Antarctic Dry Valleys are unique on Earth, yet threatened by catastrophic ecosystem shift due to climate change. - A pilot survey in January 2008 by the PI identified for the first time lithic microbial communities throughout Dry Valleys locations. - There is no existing information on landscape scale ecology for such communities, thus the actual distribution of the main biotic component of the Dry Valleys is unknown. - Species composition of these communities is not understood, especially which taxa are metabolically active. The Antarctic Dry Valleys provide an ideal natural observatory for testing fundamental ecological hypotheses of broader relevance to microbial ecology - This terrestrial Antarctic ecosystem is ideal for studies of relevance to broader issues in microbial ecology: It is dominat ed by microbial processes and characterized by low-complexity microorganism-driven food-webs, with a relatively limited range of abiotic drivers affecting diversity but high selective pressure due to extreme conditions. - The degree to which microorganisms exhibit phylogeography remains unresolved, and the isolated Antarctic location is ideal for phylogeographic studies. The PI has the only global collection of samples from arid and hyper-arid deserts on every continent on Earth for comparison, thus giving true global significance to the study. - There is currently no consensus on the evolutionary origins of Antarctic microbiota, and the phylogenetic dataset proposed by this study will address this. - Landscape scale studies that allow meaningful statistical inferences of abiotic variables at the community level are lacking, and an Antarctic model would have far-reaching applications in other areas of microbial ecology.


Project Title: Xth SCAR International biology Symposium Dry permafrost polygonal terrain in the Antarctic Dry Valleys supports multiple lithic microbial niches
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Metabolically active microbial community in semi-arid, arid and hyper-arid soils in China's Taklimakan Desert
Investigator(s): Pointing SB
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 02/2010
Abstract:
The objectives of the proposed study are to: 1. Establish metabolically active fractions of total microbial community (archaea, bacteria, eukarya) in semi-arid, arid and hyper-arid regions of the Taklimakan Desert in western China. 2. Determine the influence of abiotic factors on microbial community development, with particular focus on the role of salinity-related variables. 3. Elucidate the ability of soil communities to fix carbon and nitrog en in situ and under simulated stress in laboratory conditions. Key issues and problems to be addressed 1. Deserts constitute the most abundant biome in China (>30% land mass) and on a global scale are the most prevalent terrestrial ecosystem (>16% global land mass). Desertification (creation of new desert) is an increasing concern in China and worldwide, with serious economic consequences. 2. Desert soils are poorly understood in terms of their microbiota and their ecological role in soil conditioning. The few studies undertaken have focused upon morphology and DNA-based biodiversity and so no indication of which microbes are active is available. This is especially pertinent given the ability of many desert microbes to produce resting structures. 3. Microbial carbon and nitrogen input to desert soils are critical steps in creating conditions suitable for higher plants and the contribution of soil microorganisms requires quantifying. 4. Soil Salinization and catastrophic ecosystem shift resulting from long term water stress is a major environmental concern in China, and evidence is emerging that microbial colonization may mitigate this process. The major studies undertaken on desert microbiology in recent years have been published by the PI and so he is well-placed to move forward this field of research: 1. Pointing SB, Warren-Rhodes K, Lacap DC, Rhodes KL and McKay CP (2007) Hypolithic community shifts occur as a res ult of liquid water availability along environmental gradients in China’s hot and cold hyperarid deserts, Environmental Microbiology 9: 414-424 (impact factor 4.9). 2. Warren-Rhodes KA, Rhodes KL, Boyle LN, Pointing SB, Chen Y, Liu S, Zhou P and McKay CP (2007) Cyanobacterial ecology across environmental gradients and spatial scales in China's hot and cold deserts, FEMS Microbiology Ecology 61: 470-482 (impact factor 3.3). 3. Warren-Rhodes K, Rhodes KL, Pointing SB, Ewing S, Lacap DC, Gómez-Silva B, Amundson R, Friedmann IE and McKay CP (2006) Hypolithic cyanobacteria, dry limit of photosynthesis and microbial ecology in the hyperarid Atacama Desert, Chile, Microbial Ecology 52: 389-398 (impact factor 2.8).


List of Research Outputs

Pointing S.B. , Ecology of terrestrial thermophiles: insights from field sites in Tibet, Thermophiles 2009, Beijing, China . 2009.
Pointing S.B. , Chan Y., Bugler-Lacap D.C. , Lau C.Y. , Jurgens J.A. and Farrell R.L., Highly specialized microbial diversity in hyper-arid polar desert, Proceedings of the National Academy of Sciences . 2009.
Pointing S.B. , Service Contribution Award, Faculty of Science, HKU . 2009.
Wong F.K.Y., Bugler-Lacap D.C. , Lau C.Y. , Aitchison J.C. and Pointing S.B. , Hypolithic colonization of quartz pavement in the high altitude tundra of central Tibet, Microbial Ecology . 2010.
Wong K.Y. , Lau C.Y. , Bugler-Lacap D.C. , Aitchison J.C. , Cowan D.A. and Pointing S.B. , Endolithic microbial colonization of limestone in a high-altitude arid environment, Microbial Ecology . Springer Science, 2009, 59: 689-699.


Researcher : Sadovy YJ

Project Title: 6th Indo-Pacific Fish Conference The Society for the Conservation of Reef Fish Aggregation (SCFRA) Perplexing Problems of Sexual Patterns in the Genus Paralabrax
Investigator(s): Sadovy YJ
Department: Ecology & Biodiversity
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 05/2001
Abstract:
N/A


Project Title: Molecular population structure of three commercially important groupers in the Indo-Pa cific
Investigator(s): Sadovy YJ
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) Determine whether the populations of the three species are open or closed, And if closed, what the degree of connectivity among regions; (2) As the spawning aggregation dynamics of the two target species differ in spatial scale, our comparative analysis will help to discriminate any relationship between patterns of aggregation behavior and genetic connectivity in aggregating reef fishes of relevance to both management and an understanding of population demography.


Project Title: Population genetic structure of an exploited marine aquarium fish, the mandarinfish, Synchiropus splendidus revealed using microsatellite markers
Investigator(s): Sadovy YJ, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2009
Abstract:
World popularity in the marine aquarium hobby ha s been increased since 1990s (FAO 1995). Although hundreds of different species may be taken for marine aquaria, the most intensely targetted marine fish for the aquarium industry are represented by are relatively few species. Among 4000 coral reef fishes with less than 7.5% speci es collected (FAO 1995). Most of these species are demanded because of their conspicuous colour or special fin morphology, and because of their small size. Until now, 95% of these species are wild-caught from the coral reef environment (Polunin & Roberts 1996; Chan & Sadovy 1998). The mandarinfish or mandarin dragonet (Synchiropus splendidus), is a small and colourful member of the dragonet family (Callionymidae), which is one of the favorite choices in the marine aquarium trade including in Hong Kong (Chan & Sadovy 1998). The mandarinfish is native to the west Pacific region, distributed from the Ryukyu Islands of southern Japan to New Caledonia (Myers 1999). Because of their spectacular fin morphology fishing pressure particularly focused on the males, especially the large ones (Sadovy et al. 2001) and about 70% of caught individuals were recorded to be males. Despite their popularity in the aquarium trade, mandarinfish are considered difficult to maintain in captivity as their feeding habits are very specific (Wilkerson 1996), and their mortality in captivity is typically very high. The Philippines is an important source of the mandarinfish for the aquarium trade (Debelius & Baensch 1994), and exploitation has been particularly high from a circumscribed geographic area located centrally the island of Batasan (Sadovy et al. 2001). The mandarinfish was a major source of income for this Island, and during the peak fishing period (1987-1995), fishers were able to capture at least 1000 fish in 3 hours. Notable reductions in fish size (from average 60 mm TL to 30 mm TL, close to the size of sexual maturation) and abundance was recorded by 1990 (Sadovy et al. 2001). The fishing activity for the mandarinfish is still active although it is not as high as in 1990s, and the fish abundance has not yet recovered back to former levels. In recent years, concerns have been expressed in relation to heavily exploited fish species because of the possibility that exploitation pressures could become a powerful selection pressure if fishing mortality is much more than natural mortality rates or is highly selective (Consuegra et al. 2005). Potential impacts of genetic changes of the exploited populations could be: alteration of population subdivision, loss of genetic variation, and selective genetic changes such as?? (Allendorf et al. 2008). Understanding the genetic changes and evolutionary responses of exploited populations is crucial for management designs aimed at sustainable exploitation of natural populations (Walsh et al. 2006). The mandarinfish is a valued marine aquarium fish subjected to a heavy sex-selective fishery on larger males for their higher attractiveness to aquarists and better value to fishers. Being one of the smallest of all marine pelagic spawners, the mandarinfish has a low fecundity (egg batch size ranges from 12-205), spawns in sheltered inshore waters and has very short larval durations (about 14 days) (Sadovy et al. 2001). In some ways similar to clownfish, this species is likely to show higher population structure than other pelagic spawners (Buston et al. 2007). In addition to its life history, the male-based selective fishery on the mandarinfish could affects mating systems because females prefer to spawn with large males (PI’s unpublished data), and thus potentially affect the recruitment (Vincent & Sadovy 1998; Allendorf and Hard 2009). In this proposed study, we will use a population genetic approach to investigate potential discrepancies between population s subjected to different levels of fishing pressure over a meso-geographical spatial scale across the central Philippines using microsatellite markers. Microsatellites are genetic markers, which have been applied and shown to be very sensitive (Ng et al. 2003) and ideal for population structure analyses in different organisms (Rhodes et al. 2003; Ng et al. 2009). By examining for population genetic sub-structuring in a commerciall y important marine fish, within a relatively circumscribed geographic area and including areas under high and low fishing pressure, the results from the proposed research could have important conservation and management implications (Vincent & Sadovy 1998). Research objectives: (1) To isolate and characterize novel polymorphic microsatellite markers for population analysis of the mandarinfish. (2) To investigate genetic sub-structuring of the mandarinfish across the Philippines using newly developed polymorphic microsatellite marker from objective (1). Allendorf FW, England PR, Luikart G, Ritchie PA, Ryman N (2008) Genetic effects of harvest on wild animal populations. Trends in Ecology & Evolution 23(6):327-337. Allendorf FW, Hard JJ (2009) Human-induced evolution caused by unnatural selection through harvest of wild animals. Proceeding of the National Academy of Sciences of the United States of America 106: 9987-9994 Suppl. 1. Buston PM, Bogdanowicz SM, Wong A, Harrison RG (2007) Are clownfish groups composed of close relatives? An analysis of microsatellite DNA variation in Amphiprion percula. Molecular Ecology 16: 3671–3678. Chan TTC, Sadovy Y (1998) Profile of the marine aquarium fish trade in Hong Kong. Aquarium Sciences and Conservation 2:197-213. Consuegra S, De Leaniz CG, Serdio A, Verspoor E (2005) Selective exploitation of early running fish may induce genetic and phenotypic changes in Atlanti c salmon. Workshop on Genetic Protein Variation in the Atlantic Salmon pp129-145. Debelius H, Baensch HA (1994) Marine Atlas. Mergus, USA. FAO (1995) Review of the State of World Fishery Resources: Aquaculture. FAO Fisheries Circular, Rome. Myers RF (1999) Micronesian Reef Fishes. 3rd edn. Coral Graphics, Guam. Ng WC, Sadovy Y, Leung FCC (2003) Mating system of the rockfish, Sebastiscus marmoratus as revealed by DNA fingerprinting. Ichthyological Research 50(4): 339-348. Ng, W.C., Chan, M.N., Slingsby, G., Williams, G.A. & Leung, F.C.C., 2009. Isolation and characterization of microsatelli te markers from the limpet Cellana grata. Molecular Ecology Resources 9(3): 902-904. Polunin NVC, Robert CM (1996) Reef Fisheries. Chapman and Hall, London. Rhodes KL, Lewis RI, Chapman RW and Sadovy Y (2003) Genetic structure of camouflage grouper, Epinephelus polyphekadion (Pisces: Serranidae), in the western central Pacific. Marine Biology 142: 771-776. Sadovy Y, Mitcheson G, Rasotto MB (2001) Early development of the mandarinfish Synchiropus splendidus (Callionymidae), with notes on its fishery and potential for culture. Aquarium Sciences and Conservation 3: 253-263. Vincent, ACJ, Sadovy Y (1998). Reproductive ecology in the conservation and management of fishes. In Behavioural Ecology and Conservation Biology (T Caro ed.). Oxford University Press, New York, pp. 209-245. Walsh MR, Munch SB, Chiba S, Conover DO (2006) Maladaptive changes in multiple traits caused by fishing: impediments to population recovery. Ecology Letters 9: 142–148. Wilkerson J (1996) C-Quest Hatchery-Innovations in captive ornamental marine fish culturing. Freshwater and Marine Aquarium 19(4): 123ff.


List of Research Outputs

Albins M. .A., Hixon M. .A. and Sadovy Y.J. , Threatened fishes of the world: Epinephelus striatus (Bloch, 1792) (Serranidae), Environmental Biology of Fishes . 2009, 86: 309-310.
Rasotto M. .B., Sadovy Y.J. and Mitcheson G.R. , Male body size predicts sperm number in the mandarinfish, Journal of Zoology . 2010, 281: 161-167.
Sadovy Y.J. , Liu M. and Suharti S., Gonadal development in a giant threatened reef fish, the humphead wrasse Cheilinus undulatus, and its relation ship to international trade, Journal of Fish Biology . 2010, 77: 706-718.


Researcher : Saunders RMK

Project Title: Systematics and phylogenetics of Uvaria (Annonaceae) and related genera: an integrated morphological, molecular and ecological approach
Investigator(s): Saunders RMK, Su YCF
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2006
Abstract:
(1) analysis of morphology, ultrastructure and anatomy: delimitation of taxonomic characters and preliminary assessment of character homology (based on Uvaria species from western Malesia); (2) Development of a species-level classification of Uvaria species in western Malesia; (3) Gene sequencing and phylogenetic analysis (selected Uvaria species); (4) analysis of phenology and reproductive biology (selected Uvaria species); (5) analysis of species conservation status (for Uvaria species from western Malesia)


Project Title: Molecular phylogenetics of Cananga, Cyathocalyx and Drepananthus (Annonaceae): implications for generic delimitation, morphological evolution, and historical biogeography
Investigator(s): Saunders RMK, Su YCF
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2007
Abstract:
(1) To reconstruct the phylogeny of the Cyathocalyx group using a ‘multigene’ approach in order to assess generic monophyly and delimitation, and recognise supraspec ific taxa within genera. (2) On the basis of the generic delimitation achieved, to prepare the unpublished species-level classification of Cyathocalyx sensu lato for publication as a monograph (or as separate monographs of Cyathocalyx sensu stricto and Drepananthus, as appropriate) in the Systematic Botany Monographs series. (3) Using the phylogeny developed, to assess morphological homologies and examine the evolution of morphological characters and selected ecological processes. (4) To interpret the historical biogeography of the group using cladistic methods, parsimony analysis of endemism (PAE), and event-based methods.


Project Title: Homeotic mutation and floral evolution in the Dasymaschalon-Desmos-Friesodielsia clade (Annonaceae) of basal angiosperms
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
The Annonaceae is a species-rich pantropical family of trees and woody climbers. The family is of phylogenetic significance as they possess many apomorphic characteri stics despite being ‘basal angiosperms’, derived from lineages that appeared before the evolution of the eudicots. Recent phylogenetic research by the PI’s research group has highlighted confusion in the existing delimitation of three closely related genera, Dasymaschalon (27 species), Desmos (25–30 species) and Friesodielsia (40–60 species). Phylogenetic relationships between Dasymaschalon and Desmos remain unresolved, with Dasym aschalon species represented by two clades that form a polytomy with a clade composed of Desmos species. In addition, Friesodielsia is shown to be polyphyletic, with a clade of Asian representatives (consisting of F. desmoides and F. kingii) sister to one of the Dasymaschalon clad es; the other Friesodielsia species sampled are not closely related. This research proposal focuses on this Dasymaschalon-Desmos -Friesodielsia clade, with the objective of increasing resolution and investigating morphological character evolution, with particular reference to floral structures. Preliminary data generated by members of the PI’s research group (J. Wang, Y.C.F. Su & R.M.K. Saunders, unpubl. data) consists of sequences of two coding and two non-coding chloroplast DNA regions: matK, psbA-trnH spacer, rbcL and trnL-F spacer. Although Dasymaschalon has been extensively sampled, with 22 of the total 27 species (c. 80%), the other genera have been comparatively poorly sampled, with only eight species of Desmos and four species of Friesodielsia. Further sampling of the latter genera is clearly essential, although for the purposes of this study only representatives of the Friesodielsia clade associated with Dasymaschalon will need to be sampled. The close phylogenetic relationship between Dasymaschalon, Desmos and Fries odielsia (pro parte) is superficially surprising, since they possess markedly divergent floral forms. The flowers of all three genera have a partially enclosed ‘pollination chamber’ associated with pollination by small beetles, although the anatomical structure of this chamber var ies. Desmos flowers have six subequal petals in two whorls of three; the inner petals are basally constricted around the androecium and gynoecium, with small apertures (enabling access by pollinators) at the base of the inner petals partly obstructed by the base of the outer petals. Friesodielsia flowers also have six petals in two whorls of three, but the pollination chamber is formed by apically connivent inner petals; the apert ures between the base of the inner petals are again partly obstructed by the base of the outer petals. Dasymaschalon shows a very different floral structure, however, with only three petals in a single whorl; the position of these petals indicate that they are unequivocally homolo gous with the outer petals of Desmos and Friesodielsia. Despite the different developmental origin of these petals, they are structurally identical to the inner petals of Friesodielsia. This suggests that floral evolution in the Dasymaschalon-Desmos-Friesodielsia clade may have involved a disruption to the genetic control of floral organ development. Early studies of the genetics of floral development were focused on the model flowering plants Arabidopsis (Brassicaceae) and Antirrhinum (Plantaginaceae). These studies enabled clarification of the ‘ABC model’, which suggests tha t the identity of floral organs is specified by at least three classes of homeotic genes, A, B and C; expression of the B-function genes provides the critical difference between sepals (A) and petals (AB), and between stamens (BC) and carpels (C) (e.g., V.A. Albert et al. in D.E. Soltis et al., eds., Molecular Systematics of Plants, vol. 2: 349–374; 1998). Alternative hypotheses have been derived to explain the control of floral development in basal angiosperms, which generally show poor differentiation between sepaloid outer tepals and petaloid inner tepa ls (e.g., D.E. Soltis et al., Ann. Bot. 100: 155–163; 2007). Unlike most basal angiosperms, however, the Annonaceae have flowers that show clear differentiation between sepals and petals. Despite the lack of homology between the sepal-petal distinction in eudicots and the Annonaceae, floral development in Asimina (Annonaceae) appears to be controlled by an ABC model paralleling that described for eudicots (S. Kim et al., Pl. J. 43: 724–744; 2005). An elaboration of this ABC model presumably operates in most Annonaceae genera, including Desmos and Friesodielsia, which show a morphological distinction between the inner and outer whorls of petals. Recognition of the extensive morphological differences between the perianths of Dasymaschalon, Desmos and Friesodielsia flowers as a series of distinct characte rs and character states does not enable identification of a parsimonious explanation of evolutionary change. It can be hypothesised, however, that the extensive changes in perianth structure are the product of homeotic mutations, in which inner petal development in Dasymaschalon is suppressed, with outer petal development controll ed by the genes previously responsible for inner petal development. Circumstantial support for this hypothesis is found in two Dasymaschalon species, D. macrocalyx and D. trichophorum, which form a well-supported clade (1.00 posterior probability) in preliminary Bayesian phylogenetic analyses (J. Wang, Y.C.F. Su & R.M.K. Saunders, unpubl. data). These species both have sepals that are large and resemble the outer petals of Friesod ielsia, in contrast with all other Dasymaschalon species which have very small sepals. As with most Annonaceae, the sepals only enclose the flower buds in the very earliest developmental stages and hence do not protect the develop ing floral organs. Given the apparent absence of any functional explanation for the enlarged sepals of D. macrocalyx and D. trichophorum, it is possible that their evolution is also the result of a homeotic mutation, with developm ent controlled by genes previously responsible for outer petal development. The proposed research aims to clarify problems of generic delimitation in the Dasymaschalon-Desmos-F riesodielsia clade by generating phylogenetic hypotheses with improved resolution and statistical support, based on a more comprehensive level of taxon sampling. The reconstructed phylogeny will enable interpretation of morphological character evolution, with emphasis on floral evolution. In particular, the phylogeny will be used to interpret the possibility of homeotic mutations as an explanation for changes in perianth structure.


Project Title: Molecular phylogenetics of Polyathia (Annonaceae): identifying clades and morphological synapomorphies in a large polyphyletic genus
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2009
Abstract:
1) To increase the taxonomic breadth of the phylogenetic analyses by incorporating more species than sampled previously, including species of Polyalthia and relat ed genera; 2) To increase the resolution and support of the phylogenetic reconstructions of Polyalthia sensu lato by assessing the utility of other gene regions for multiple-gene analyses; 3) To identify morphological synapomorphies for each of the constituent clades in order to enable taxonomic recognition as distinct genera; 4) To resolve outstanding nomenclatural problems and validate new generic names and species combinations as required; 5) To estimate divergence times for individual clades and elucidate patterns of historical biogeography.


Project Title: Molecular phylogenetics of the Fitzalania-Meiogyne clade (Annonaceae): taxonomic and biogeographical implications
Investigator(s): Saunders RMK
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2010
Abstract:
The Annonaceae is a species-rich pantropical family of flowering trees and woody lianas. The family is of phylogenetic significance as they possess many apomorphic characteristics despite being ‘basal angiosperms’, derived from lineages that appeared before the evolution of the eudicots. The PI’s research group is now one of the leading international teams studying the phylogeny of the family, and using the results to address ques tions in higher-level systematics, evolutionary diversification and historical biogeography. The genus Fitzalania consists of only two species from Queensland, Australia (Jessup, Fl. Australia 2: 18-57; 2007), whereas Meiogyne consists of 15 described species, ranging from southern India to New Caledonia (van Heusden, Blumea 38: 487-511; 1994; van Heusden, Bull. Mus. Natl. Hist. Nat., B, Adansonia 18: 75-83; 1996; Jessup, l.c.). The PI is currently preparing descriptions of two previously unknown species for publication. Mols et al. (Amer. J. Bot. 91: 590-600; 2004) included four Meiogyne species and one Fitzalania species in a broad-ranging molecular phylogenetic analysis (based on rbcL and trnL-F regi ons), and showed that the Fitzalania species was nested within a clade composed of the Meiogyne species. Additional sequences for the second Fitzalania species and another Meiogyne species have since been generated in the PI’s lab, and a similar topology retrieved following phylog enetic analysis. Although the levels of taxon sampling are inadequate, the topology indicates that Fitzalania and Meiogyne are likely to be congeneric. One of the initial aims of this project will therefore be to increase the number of species sampled and the range of gene regions sequenced to ensure a well-resolved and well-suppo rted phylogeny. It will then be possible to validate the new nomenclatural combinations arising from the transfer of the Meiogyne species names to the older generic name, Fitzalania, as necessary. Most of the species in the Fitzalania-Meiogyne clade occur east of Wallace’s line, with one species in New Britain (off the east coast of New Guinea), five species in Queensland, Aust ralia, and five species in New Caledonia. This centre of diversity in Australasia is unusual within the Annonaceae, although similar distribution patterns have been observed in a few other genera, such as Pseuduvaria (Su & Saunder s, Syst. Bot. Monogr. 79: 1-204; 2006; Su & Saunders, BMC Evol. Biol. 9: article 153; 2009). Several large-scale biogeographical studies of the Annonaceae have indicated a probable origin in South America and/or Africa, with subsequent dispersal into Asia, either via India and/or southern Europe and central Asia (e.g., Doyle et al., Int. J. Pl. Sci., 165, suppl. 4: S55-S67; 2004; Richardson et al., Philos. Trans. Roy. Soc. Lond., B 359: 1495-1508; 2004). This is consistent with the observation that most Asian Annonaceae genera have a centre of diversity in western Malesia. The unusual geographical distribution of the Fitzalania-Meiogyne clade raises several interesting questions relating to the timing of the presumed dispersal events. Preliminary biogeographical optimizations suggest that early representatives of the Fitzalania-Meiogyne clade are likely to have dispersed eastwards across Malesia, towards Australia and New Caledonia. The best opportunity for biota to “island hop” across Wallacea appears to have been during the last 5 million years, due to: (1) the formation of a substantial landmass in Sulawesi from ca. 5 Mya (Hall, in Metcalfe et al., eds., Faunal and Floral Migrations and Evolution in SE Asia-Australasia, 35-56; 2001); (2) the connection between New Guinea and Sundaland via the Banda and Sunda arcs (Hall, in Hall et al., Biogeography and Geological Evolution of SE Asia, 99-131; 1998); (3) the increasing number of volcanic islands in East Indonesia (Barby & Pierce, Syst. Entomol. 32: 2-25; 2007); (4) the exposure of the Sunda and Sahul Shelves caused by falling sea levels (up to 120 m lower than present levels) during the Pleistocene glaciations (Inger & Voris, J. Biogeogr. 28: 863-891; 2001); and (5) the accretion of microcontinental island arc fragments at the northern edge of the Australian craton portion of New Guinea (Hall in Metcalfe et al., l.c.). We will use uncorrelated lognormal (UCLD) relaxed molecular clock methods to estimate diversification times of the relevant nodes within the phylogeny, with the objective of ascertaining whether the estimated ages are consistent with the geological and palaeoclimatic data available. The taxonomic diversity in New Caledonia is also of considerable biogeographical interest. Analysis of the phytogeographical relationships of the rainforests of New Caledonia (Mora t et al. in Radovsky et al., eds., Biogeography of the Tropical Pacific, 71-128; 1984) suggests that there are two main floristic elements, reflecting associations with Australia and Malesia. The Australian floristic component was previously hypothesized to have resulted from ancient Gondwanan lineages that existed prior to the tectonic separation of New Caledonia from Australia (which occurred approximately 75 Mya according to Ha ll, J. Asian Earth Sci. 20: 353-431; 2002), whereas the Malesian floristic component was regarded as the result of later long-distance dispersal events (Morat et al., l.c.). The New Caledonian representatives of the Annonaceae have been cited as an example of a lineage derived from the break-up of Gondwana (Lowry in Peng & Lowry, eds., Rare, Threatened, and Endangered Floras of Asia and the Pacific Rim, 181-206; 1998; Jaffré et al., Composition et Caractéristiques de la Flore Indigène de la Nouvelle-Calédonie; 2001). Recent geological research, however, has indicated that New Caledonia was completely submerged during the Palaeocene (Aitchison et al., Geology 23: 161-164; 1995), suggesting that all existing lineages in the island’s flora are likely to have been derived by long-distance dispersal with subsequent diversification. Estimates of the ages of the nodes in the phylogeny will again be compared with the available geological and palaeoclimatic data, and will clarify when representatives of the Fitzalania-Meiogyne clade first migrated to New Caledonia.


List of Research Outputs

Attanayake M.A.S...A... , Ratnayake R.M.C. and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Attanayake M.A.S...A... and Saunders R.M.K. , Pollination ecology and breeding system of Uvaria semecarpifolia (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.
Chatrou L.W., Richardson J.E., Erkens R.H.J. and Saunders R.M.K. , Natural History of the Annonaceae . 2009.
Ho G.W.C., Mar S.S. and Saunders R.M.K. , Thismia tentaculata (Burmanniaceae tribe Thismieae) from Hong Kong: first record of the genus and tribe from continental China, Journal of Systematics and Evolution . 2009, 47: 605-607.
Pang C.C. and Saunders R.M.K. , Floral phenology and breeding system of Desmos chinensis (Annonaceae): protogyny and intra-individual floral synchronicity to promote out-crossing, 1st Meeting of Biosyst EU 2009 & 7th Biennial Confe rence of the Systematics Association, Leiden, 10-14 August . 2009.
Ratnayake R.M.C.S., Gunatilleke I.A.U.N. and Saunders R.M.K. , Phenology of Xylopia championii in an aseasonal rainforest of Sri Lanka and its correlation with climate, 5th International Canopy Conference, Bangalore, 25-31 October . 2009.
Ratnayake R.M.C.S. and Saunders R.M.K. , Vegetative and reproductive phenology of Polyalthia coffeoides in Sri Lanka, 29th Annual Session of the Institute of Biology, Sri Lanka . 2009.
Ratnayake R.M.C.S., Gunatilleke I.A.U.N. and Saunders R.M.K. , Vegetative and reproductive phenology of Polyalthia korinti and correlation with weather pattern in Sri Lanka, 5th International Canopy Conference, Bangalore, 25-31 October . 2009.
Saunders R.M.K. and Su Y.C.F. , A Late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent diversification in New Guinea, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Saunders R.M.K. , Associate Editor, , Botanical Journal of the Linnean Society . 2010.
Saunders R.M.K. , Homeotic mutations and floral evolution in the Annonaceae, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Saunders R.M.K. , Journal of Systematics and Evolution . 2010.
Saunders R.M.K. , Member of editorial board, Thai Forest Bulletin . 2009.
Saunders R.M.K. , Specialist Adviser, Registrar of Plant Variety Rights, Intellectual Property Department, Hong Kong Government . 2010.
Su Y.C.F. and Saunders R.M.K. , A late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent dispersal in New Guinea, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Su Y.C.F. , Chaowasku T. and Saunders R.M.K. , An extended phylogeny of Pseuduvaria (Annonaceae), with descriptions of three new species and a reassessment of the generic status of Oreomitra, Systematic Botany . 2010, 35: 30-39.
Su Y.C.F. and Saunders R.M.K. , Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea, BMC Evolutionary Biology . 2009, 9: art. 153 (19 pp).
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annon aceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.
Wang J. , Chalermglin P. and Saunders R.M.K. , The genus Dasymaschalon (Annonaceae) in Thailand, Systematic Botany . 2009, 34: 252-265.
Weerasooriya A.D. and Saunders R.M.K. , Monograph of Mitrephora (Annonaceae), Systematic Botany Monographs . Ann Arbor, Michigan, American Society of Plant Taxonomists, 2010, 90: 1-167 + 4 colour plates.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cyathostemma, Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodor um, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Shan B

List of Research Outputs

Shan B. , Cai Y. , Brooks J.D. and Corke H. , Antibacterial and antioxidant effects of five spice and herb extracts as natural preservatives of raw po rk, Journal of the Science of Food and Agriculture . 2009, 89 (11): 1879-1885.


Researcher : Shi M

List of Research Outputs

Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Shih CH

List of Research Outputs

Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyantho cyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Shih CH

List of Research Outputs

Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocya nidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Lo C.S.C. , Yu K.Y. , Shih C.H. , Du Y. and Chu H. , Molecular dissection of pathogen-inducible flavonoid pathway in sorghum, XIV International Congress on Molecular Plant-Microbe Interactions . 2009.


Researcher : Sin YT

List of Research Outputs

Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscylliu m plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Sit WH

List of Research Outputs

Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wan J.M.F. , Sit W.H. and Yang X., Polysaccharopeptide of Coriolus versicolor enhances the Anticancer Activity of Camptothecin (CPT) on Human Leukemic HL-60 Cells, The 5th International medicinal Mushroom Conference . 2009, 691-702.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.
Zhong W. , Sit W.H. , Wan J.M.F. and Yu A.C.H. , Sonoporation-induced apoptosis and cell-cycle arrest: initial findings, International Symposium on Therapeutic Ultrasound . 2010, D3-1.


Researcher : Su X

List of Research Outputs

Su X. and Tsang J.S.H. , Identification of a second haloacetic acid transporter in a haloacetate degrading bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . 2010.


Researcher : Su YCF

List of Research Outputs

Saunders R.M.K. and Su Y.C.F. , A Late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent diversification in New Guinea, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Su Y.C.F. and Saunders R.M.K. , A late Miocene origin of the basal angiosperm genus Pseuduvaria (Annonaceae) in Sundaland, with subsequent dispersal in New Guinea, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Su Y.C.F. , Chaowasku T. and Saunders R.M.K. , An extended phylogeny of Pseuduvaria (Annonaceae), with descriptions of three new species and a reassessme nt of the generic status of Oreomitra, Systematic Botany . 2010, 35: 30-39.
Su Y.C.F. and Saunders R.M.K. , Evolutionary divergence times in the Annonaceae: evidence of a late Miocene origin of Pseuduvaria in Sundaland with subsequent diversification in New Guinea, BMC Evolutionary Biology . 2009, 9: art. 153 (19 pp).
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cy athostemma, Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodorum, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Sun M

Project Title: Molecular evolution of SSIIa gene during domestication and SNP markers for rice breeding
Investigator(s): Sun M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2009
Abstract:
Oryza sativa is one of the oldest domesticated crop species in the world, and O. rufipogon, found widely in Asia, is believed to be the wild progenitor of domesticated rice (Khush 1997). The two species differ in a variety of quantitative traits, including panicle and spikelet structure, seed weight, and seed dormancy. Two major subspecies, O. sativa ssp. indica and O. sativa ssp. japonica, together account for most of the rice cultivars and landraces currently grown. Domestication of wild rice probably started about 11,000 years ago. Domestication in Asia could have occurred independently and concurrently at several sites (Khush 1997). A recent phylogeographic study has shown that cultivated rice was independently domesticated at least twice from different O. rufipogon populations, which resulted in the two subspecies, indica and japonica (Londo et al 2006). The subspecies indica was domesticated within a region south of the Himalaya mountain range, likely eastern India, Myanmar, and Thailand, whereas japonica was domesticated from wild rice in southern China (Londo et al 2006). During the long history of rice domestication and cultivation, divergent starch qualities of the grain may be selected and selection could have acted on the starch biosynthesis genes. For example, the splice-site mutation of Wx gene has been under selection in most low-amylose rice landraces cultivated widely in Northeast Asia. And sequence analysis has suggested that selection pressures associated with crop domestication can even exceed those observed for genes under strong natural selection. Our previous work has shown that two continuous single-nucleotide polymorphisms (SNPs), GC/TT of starch synthase IIa (SSIIa) in cultivated rice, have a very strong associ ation with gelatinization temperature (GT) of starch, and can be used to differentiate high or intermediate GT rice from low-GT rice. Other cereal crops, such as wheat, barley and maize, all captured the same amino acid associated with high-GT as rice, suggesting that the related SNP allele GC is most likely the ancestral or wild type in rice. However, polymorphisms at the SNP sites could also exist in wild rice O. rufipogon. Similarly, another important SNP (A/G, 31 bp upstream of the GC/TT SNPs) was found to be crucial for SSIIa activity in cultivated rice. In this project, we will investigate the molecular evolution of SSIIa in relation to GT during rice domestication and breeding. The eating, cooking and processing qualities of rice and rice products are mainly influenced by physicochemical properties of its starch, which accounts for about 90% of milled rice. Starch is composed of amylose and amylopectin, and apparent amylose content has been well recognized as one of the most important determinan ts of rice quality. In addition, differences in amylopectin structure affect rice eating and textural qualities. Gelatinization temperature, one of the most important indicators of cooking quality and processing characteristics of rice starch, is controlled by the fine structure of amylopectin. The project objectives are: 1. To study GC/TT, A/G, and other related polymorphic SNPs in different wild rice populations and their relationship with gelatinization temperature. Wild populations of O. rufipogon from Yunnan, Guangxi and Jiangxi provinces of mainland China will be genotyped and used for measur ement of gelatinization temperature following the methods already developed in our laboratories. 2. To compare SSIIa gene sequence diversity among wild rice, landraces, and cultivars to investigate genetic consequences of domestication. Comparative analysis of gelatinization temperature and other physicochemical properties will also be conducted for these rice samples. 3. To determine the effect of domestication on the other genes up- and down-stream of SSIIa. Domestication and artificial selection on the target genes may have a strong hitchhiking effect on the genes nearby, which can be detected by the sequence diversity analysis. 4. To determine association of SNPs with gelatinizati on temperature in wild rice and compare with the findings in cultivated rice, and to develop PCR-based molecular markers for rice breeding.


Project Title: Botany & Mycology 2009 Molecular identification of hybridization and introgression in Bruguiera (Rhizophoraceae)
Investigator(s): Sun M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Sun M. , Molecular identification of hybridization and introgressi on in Bruguiera (Rhizophoraceae). , Botany & Mycology 2009, Snowbird, Utah, USA . 2009.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemica ls of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.


Researcher : Sun Z

List of Research Outputs

Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Sun Z

List of Research Outputs

Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproduc ts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.


Researcher : Surveswaran S

Project Title: 7th Biennial Conference of the Systematics Association Phylogeny of the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group
Investigator(s): Surveswaran S
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Abstract:
N/A


List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Surveswaran S

List of Research Outputs

Huang W. , Cai Y. , Surveswaran S. , Hyde K.D. , Corke H. and Sun M. , Molecular phylogenetic identification of endophytic fungi isolated from three Artemisia species. , Fungal Diversity . 2009, 36: 69-88.
Surveswaran S. , Cai Y. , Xing J., Corke H. and Sun M. , Antioxidant properties and principal phenolic phytochemicals of Indian medicinal plants from Asclepiadoideae and Periplocoideae, Natural Product Research . 2010, 24(3): 206-221.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Molecular phylogeny and character evolution in the Cananga-Cyathocalyx-Drepananthus (Annonaceae) group, 1st Meeting of Biosyst EU 2009 & 7th Biennial Conference of the Systematics Association, Leiden, 10-14 August . 2009.
Surveswaran S. , Kamble M.Y., Yadav S.R. and Sun M. , Molecular phylogeny of Ceropegia (Asclepiadoideae, Apocynaceae) from Indian Western Ghats. , Plant Systematics and Evolution . 2009, 281: 51-63.
Surveswaran S. , Wang R.J. and Saunders R.M.K. , Phylogenetics of Cananga-Cyathocalyx-Drepananthus (Annonaceae), Annonaceae Workshop, Leiden, 7-9 August . 2009.


Researcher : Tam CY

List of Research Outputs

Lui W.Y. and Tam C.Y. , Itch interacts with the pre-initiation complex for gene transcription, The 34th Federation of European Biochemical Socie ties (FEBS) Congress. Jul 4-9, 2009. Prague, Czech Republic . 2009.


Researcher : Tam KV

List of Research Outputs

Lee T.O. , Tam K.V. and Chow B.K.C. , Analysis of a putative VPAC2 receptor from sturgeon shed light on molecular and functional evolution of VPAC2R in vertebrates, 9th International Symposium on VIP, PACAP and Related Peptides, Kagoshima, Japan. . 2009.


Researcher : Tan-Un KC

Project Title: Molecular and functional character isation of Cytoglobin (CYGB), a hypoxia inducible gene
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2008
Abstract:
(1) To investigate the roles of Sp1 and Sp3 proteins in the regulation of CYGB gene; (2) To characterise the potential regulatory regions that are located distal and proximal to the CYGB gene; (3) To perform a detailed study on the methylation and histone modification stautus of the corresponding CpG islands in order to better understand the underlying molecular mechanism of CYGB gene regulation (4) To analyse the activation of CYGB gene by HIF(hypoxia-inducible factors) through siRNA mediated knockdown of HIF genes; (5) To delineate the biological role of CYGB in the context of oxidative stress; (6) To investigate the association of CYGB expression and its implication in the pathogenesis of chronic obstructive pulmonary disease (COPD).


Project Title: The study of the regulatory regi ons of the human neuroglobin gene
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2009
Completion Date: 08/2010
Abstract:
Globins are oxygen-binding heme proteins found in bacteria, fungi, protists, plants and animals. In vertebrates, two well-known globins, hemoglobin(Hb) and myoglobin(Mb) have been studied for over than a century and are the representatives of the globin family. So far, the vertebrate globin family consists of Hb, Mb, neuroglobin (Ngb), cytoglobin (Cygb), globin E (eye-specific in chicken) and globin X (found in amphibians and fish). Ngb was first discovered in the brains of vertebrates [1]. It is expressed predominantly in the central and peripheral nervous systems, in the retina and in some endocrine tissues [1, 2]. In the brain, Ngb is present in neurons but absent in glia cells [3]. Ngb is hexa-coordinated whilst Hb and Mb are penta-coordinated. Small ligands such as O2, CO and NO can reversibly bind with the heme of Ngb. Phylogenetics analysis indicates that Ngb belongs to a branch of globin family which diverged early in evolution [5]. Current studies imply that Ngb may be a scavenger of NO and reactive oxygen species (ROS) and protect cells from oxidative stress [7]. It has been proposed that Ngb may have a sensoring role for O2/NO in the signal transduction pathway thus acting as a guanine-n ucleotide dissociation inhibitor (GDI) or suppressing apoptosis by reducing ferric cytochrome c [8,9]. To date, the precise function and regulation of Ngb are still unclear. In this study we propose to characterise the analyze a 2kb 5’promoter region of the human Ngb gene. We will search for potential transcription factor binding sites that mediate the regulation of Ngb gene expression.


Project Title: King's/HKU Fellowship Awards 2010-11
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: King's/HKU Fellowship Awards
Start Date: 06/2010
Abstract:
To visit the Division of Genetics and Molecular Medicine of the School of Medicine at King's College London to conduct research and to learn techniques that will assist in the investigation of mapping of regulatory regions and DNA methylation and histone modification in the cytoglobin gene locus, and to develop a new research project in Nutrigenomics.


Project Title: A conditional knockout mouse for cytoglobin
Investigator(s): Tan-Un KC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
OBJECTIVES Cytoglobin (Cygb) is a recently discovered member of the vertebrate globin superfamily. It is found in all tissues, albeit at varying levels, implicating a general function of this ubiquitously expressed protein. Key issues: Liver fibrosis is a common complication of chronic liver disease and end-stage fibrosis (cirrhosis) is a health problem in Hong Kong and world wide. It has been shown that over-expression of Cygb reduces oxidative stress, suppresses extracellular matrix de position in liver fibrosis and promotes the recovery from damage induced fibrogenesis. As a new member of the globin superfamily, cytoglobin(Cygb) was first discovered in hepatic stellate cells(HSCs) of the fibrotic liver and duly named “stellate cell activated protein” (Kawada et al.,2001 J. Biol. Chem. 276 (2001) 25318–25323.). Cygb has been characterized as a respiratory protein in connective tissues and we and others have found it to be up-regulated during hypoxia(low oxyg en) (Fordel et al., Biochem. Biophys. Res. Commun. 319 (2004) 342–348). This suggests that Cygb may play a role in the protection of the cells against oxidative stress by acting as a scavenger for ROS.. Findings from our group (Guo et al.,2007 Biochem Biophys Res Commun. 2007 Dec 7;364(1):145-50) showed that the up-regulation of Cygb was an acute response to hypoxia and was mediated by Hypoxia-inducible factor-1(HIF-1) transcription factor. Our group (Man et al.,2008 Toxicol Lett. 2008 Dec 15;183(1-3):36-44) also showed that Cygb was expressed in hepatic stellate cells(HSC) and found an increase accumulation of Cygb-positive cells during the development of CCl4-induced liver fibrosis. In fibrogenesis, stellate cells proliferate and undergo transition into myofibroblast-like cells.. As CCl4 is known to generate reactive oxygen species (ROS) we suggest that Cygb may play a crucial role in the detoxification of ROS in the pathogenesis of liver fibrosis. Noteworthy, cytoglobin has been identified to be a candidate tumor suppressor gene, as down-regulation of cytoglobin expression is observed in lung tumors. (Xinarianos et al., Hum Mol Genet. 2006 Jul 1;15(13):2038-44.) . Interestingly, we have shown that reduced expression of cytoglobin is correlated with the severity of chronic pulmonary diseases(COPD ) (unpublished data). To date, the physiological function of Cygb is still controversial. Objectives: The primary goal of this project is to understand the functional role of cytoglobin in vivo, and secondarily to address the role of Cygb in the pathogenesis of liver fibrosis. This project will generate a unique and proprietary knockout mouse for the Cygb gene which will provide a useful genetic resource for future tissu e specific KO mice and for the cytoglobin research community. Strategy: As Cygb is expressed ubiquitously in all tissues, a germ line knock out may have defects in numerous tissues or is embryonic lethal. To circumvent this problem, we propose to employ an in vivo conditional knockout Cygb mouse model to investigate the functional role of Cygb. A conditional null allele for Cygb will be generated by homologous recombination in ES cells using the the Cre-loxP and Flp-Frt systems. These conditional knockout mice should facilitate the study of the indivi dual consequences of Cygb deficiency in various tissues. Potential outcomes The expected outcomes of this study will be (figure 1): (a) the generation of Cygb fn/+ (fn denotes floxP-neo) mice carrying the targeted allele with the β-galactosidase-neomycin(β-geo) cassette as a marker. Studies from these mice will give us a global expression profile of cytoglobin during develo pment and in tissues. (b) the generation of a conditional KO heterozygous Cygb fx/+(fx denotes floxP) mice which will serve as an excellent candidate for studies on the role of Cygb in various tissues (c) the generation of GFAP(Glial fibrilliary acidic protein) conditional Cygb△/△ mice where ablation of Cygb expression is restri cted in hepatic stellate cells. It will be a model to study the relevance of Cygb in liver fibrosis. (d) the avail of generating a Cygb fn/fn homozygous KO mice as a knock-out mouse model for further investigation of the function of Cygb. The generation of a knock-out Cygb mouse will allow us to directly examine the function of this protein in vivo in the context of cellular homeostasis. Future work: The conditional knock-out mouse model will be challenged with CCl4 to induce liver fibrogenesis. This latter part of the study will be according to the method that we have previously performed (Man et al., 2009). Results from this experiment will shed light as to whether the absence of Cygb may lead to the accelerated progression to liver fibrosis.


List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.


Researcher : Tang KS

List of Research Outputs

Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptosi s resistance of non-adherent ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 1722) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptotic resistance of ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular- signal regulated kinase 1/2, Neoplasia . 2010, 12: 128-138.


Researcher : Tang WK

List of Research Outputs

Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.


Researcher : Thomson DL

List of Research Outputs

Bonner S.J., Thomson D.L. and Schwarz C.J., Time-Varying Covariates and Semi-Parametric Regression in Capture-Recapture: an Adaptive Spline Approach, Monograph, Environmental and Ecological Statistic s . 2009, 3: 657-675.
Thomson D.L. , Bird-watching and the study of environmental change, Hong Kong Bird Watching Society . 2009.
Thomson D.L. and Lebreton J.D., Conference session organiser/chair, EURING 2009 Analytic al meeting and workshop, Pescara, Italy. http://www.phidot.org/euring2009/, 2009.
Thomson D.L. , Cooch E.G. and Conroy M.J., Modeling Demographic Processes in Marked Populations, New York, Springer, 2009.
Thomson D.L. , Stability and the Habitable Planet - What does it mean for wildlife populations?, Emerging SRT Workshop - Earth as a Habitable Planet, Swire Institute of Marine Science . 2010.
Thomson D.L. , Conroy M.J., Anderson D.R., Burnham K.P., Cooch E.G., Francis C.M., Lebreton J.D., Lindberg M.S., Morgan B.J.T., Otis D.L. and White G.C., Standardising terminology and notation for the analysis of demographic processes in marked populations, Monograph, Environmental and Ecological Statistics . 2009, 3: 1099-1106.


Researcher : Tian R

List of Research Outputs

Tian R. and Tsang J.S.H. , Mutagenic analysis of the upstream regulatory region of a dehalogenase gene in Burkholderia sp. MBA4, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 76.


Researcher : To TKJ

List of Research Outputs

Wang M. , Chu I.K. and To T.K.J. , Application of epigallocatechin gallate to prevent DNA interstrand cross-links caused by reactive carbony l species, 239th ACS national Meeting, San Francisco, CA, USA, March 21-25, AGFD-84 . 2010.


Researcher : Tsang JSH

Project Title: Molecular characterization of a novel bacterial permease that transport haloacid
Investigator(s): Tsang JSH
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2006
Completion Date: 03/2010
Abstract:
(1) Confirmation of the expression of the putative permease gene; (2) confirmation of the putative gene as a second member of a haloacid operon; (3) functional analysis of the putative permease; (4) structural ana lysis of the putative permease protein.


Project Title: Utilization of a microfluidic system for teaching of biotechnology, microbiology and mole cular biology
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Run Run Shaw Research and Teaching Endowment Fund - Teaching Grants
Start Date: 08/2008
Abstract:
The beginning of the twenty-first century can be described as the decade for biological sciences. Since the year 2000 The Nobel Prizes in Medicine have been award to researchers working on many disciplines of biological systems. These include genetic regulations of programmed cell death and cell cycle control, signal transduction in the nervous system, gene silencing by means of double-stranded RNA, discovery of the bacterium Helicobacter pylori and most recently on the use of embryonic stem cells. Moreover, four of the seven Nobel Prizes in Chemistry since the beginning of the decade were also given to researchers in the biological fields. These include methods used for structural analysis of biological macromolecules, channels in cell membranes, ubiquitin-mediated protein degradation and the molecular basis of eukaryotic transcription. In order to teach students enrolled in the biologica l sciences programmes it is necessary to ensure that the most updated information will be delivered to these students. Today the major techniques used for analysis of biological systems involve the studies of DNA, RNA and protein. Preparative and analytical electrophoresis systems were normally used for these investigations. Traditionally, agarose and polyacrylamide gel electrophoresis systems were used for separation of these biomolecules. Since these biomolecules have different abundance and properties in the cell it is naturally necessary to enhance the detection of these substances with the addition of specific reagents. Ethidium bromide is usually used to bind to nucleic acids and help visualize the presence of DNA and RNA. In this detection method the samples in the gel were identified with the illumination of ultraviolet light. Since the visualization processes depended on the binding of the chemical to the biomolecules this reagent is unavoidably hazardous. Ethidium bromide is a chemical carcinogen and has been one of the chemical pollutants being transmitted easily without any notice. Ultraviolet light has also been used as a physical mutagen. It can also causes sever damage to the eyes when no protection was provided. The skins can also get burnt without any tanning effect when exposed to ultraviolet light. This obviously posed certain level of danger to the user and to the workers in the surrounding environment. Polyacrylamide has been used for the separation of proteins and for small sized DNA and/or RNA. In the old times people used to use their finger to check whether the acrylamide gel has been set or not. It has later been found that acrylamide is a neurotoxin. The use of these chemicals in teaching biological sciences subjects has to be exceptionally careful in order not to radiate their harmful effect. The use of a microfluidic automated electrophoresis system has the advantage of maintaining the separation functions while removing the hazardous aspect. No harmful che mical is used in the automated system and students will be able to appreciate the safety and usefulness of this kind of technology. When the traditional electrophoresis systems were used for analysis of DNA, RNA and protein, the sensitivities of these detection methods required the use of relatively large amount of materials. Samples containing DNA or RNA with less than 100 nanograms may not be readily visualized by the ethidium bromide staining method. Protein samples with less than micrograms of protein may not be visible in the Coomassie blue stained polyacrylamide gels. This will require the researcher to prepare more starting material and end s up in a much bigger volume that is difficult to handle. Moreover, due to the limitation of the detection chemicals the amounts of the biomolecules may not be quantified in these systems. The florescence of the ethidium bromide bound nucleic acids and the intensity of the Coomass ie blue stained proteins do not necessarily show a linear relationship with the quantity loaded into the gel. The automated electrophoresis system uses a microfluidic technology that is much more sensitive than these traditional methods. The system is able to detect as less as nanogram of DNA, RNA and protein. This is hundred times more sensitive than the conventional method. The volume required is also minimized. This will increase the accuracy of the analysis and decrease the material that is required. Moreover, the microfluidic system makes use of highly sensitive non-harmful fluorescent dyes. This allows the abundance of the individual biomolecul es to be detected and quantified. Today, we do not just talk about teaching; we will also have to talk about learning. It is necessary to provide more actual hands-on practices to the students because it can help the students to acquire and memorize the knowledge better. With the students knowing what the established methods can do, innovative and more accurate methods will be introduced for the students to compare the differences. This will train the students to learn and think more critically. In this proposal I would like to request for funding for the purchase of a microfluidic automated electrophoresis system for teaching of courses offered for the biology, biotechnology and microbiology programmes.


Project Title: IUMS 2008 XII International Congress of Bacteriology and Applied Microbiology Cloning of a putative regulator of the haloacid operon of Burkholderia cepacia MBA4
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2008
Abstract:
N/A


Project Title: Cloning and characterization of a transcriptional regulator of the haloacid operon of Burkholderia sp. MBA4
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2009
Completion Date: 12/2009
Abstract:
Burkholderia sp. MBA4 was enriched from soil using monobromoacetic acid as the sole carbon and energy source. This bacterium contains a haloacid operon, which encodes for a dehalogenase (Deh4a) and an associated permease (Deh4p). The expression of the operon has been found to be regulated. The gene products were detected only in the presence of haloacids and not when the cells were grown in pyruvate-containing or rich medium. The physical and biochemical properties of Deh4a have been well characterized and the investigation of Deh4p has also been initiated. The study on the regulation of the operon, however, is far from sufficient due to intrinsic difficulty to work on the genetics of the natural isolates. We have initiated the study by using a green fluorescent protein (GFPuv) as a report er and showed that a DNA fragment containing 100 bp of upstream non-coding sequence of the deh4a gene was sufficient for regulated expression. In silico analysis of this fragment has identified the presence of a -35 and a -10 boxes, typical of sigma-70 dependent RNA-polymerase type promoters. The use of overlapping bandshift assay showed that this 100-bp region is necessary and sufficient for the formation of retardation complexes. The biological importance of these -35 and -10 boxes was also confirmed by site-directed mutagenesis and quantitative reverse -transcriptase PCR analysis of a reporter gene. Replacement of the -10 box abolished gene expression completely. Mutation of the -35 box affected the transcriptional efficacy of the promoter. In order to obtain more information on the regulatory protein of this promoter the 100-b p fragment was ligated to form a trimer and used for making of a DNA affinity column. Cell extracts prepared from un-induced cells (grown in LB without NaCl) were fractionated by ammonium sulphate precipitation, Heparin Sepharose column and the DNA-affinity column. Fractions containing the DNA-binding ability were analyzed by SDS-PAGE gel. A 28-kDa protein was purified from the gel and digested with trypsin. The digestion products of this protein were resolved by tandem mass spectrometry and a peptide mass fingerprint was obtained. A peptide with an ion score of 100% confidence interval was also used for comparative analysis with the protein databases. The amino acids sequence of this peptide is FVLTS SVLEL SNGFL R and has been identified as part of a protein from a well-studied polychlorinated biphenyl degrader Burkholderia xenovorans LB400. This orthologous protein in LB400 has been identified as a member of the COG1414, which contains many transcriptional regulators. In this proposal I would like to clone and characterize this transcriptional regulator of the haloacid operon of Burkholderia sp. MBA4. Gene specific oligonucleotide primers will be designed according to the DNA sequences of the regulator genes in closely related species whose genomic sequences are available. These primers will then be used to amplify the corresponding gene in MBA4. The cloned gene will then be expressed in an appropriate Escherichia coli to produce sufficient amount of protein for structural and functional characterization. The expression of this regulator in MBA4 will also be investigated by quantitative reverse-transcriptase PCR to see if it were produced constitutively or in a regulated manner .


Project Title: 34th FEBS Congress Mutagenic analysis of the conserved residues of a haloacid permease
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 07/2009
Completion Date: 07/2009
Abstract:
N/A


Project Title: Purification and characterization of a DNA-binding protein of a dehalogenase producing Burkholderia
Investigator(s): Tsang JSH
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Haloacetic acids can be found in the natural environmental because of chemical and biological activities. However, most of the haloacetic acids that we detected nowada ys were produced via various human activities such as water disinfection, pesticide production and refrigerant production. Haloacetates are mutagenic and/or cytotoxic and inhibit enzyme activities in the general metabolic pathways. One of the haloacetates, monochloroacetic acid, has been used regularly in the chemical industry for making of human commodities. Monochloroacetic acid affects the citric acid cycle, gluconeogenesis and cause damages to liver and kidney. The indiscrim inate use of monochloroacetic acid has causes environmental concerns. Haloacetic acids are also produced as a result of the biodegradation of other halogenated compounds such as methyl chloride and polychlorinated biphenyls. Microorganisms have been recognized as one of the major player in remediating these harmful chemicals. Microorganisms capable of degrading these halogenated compounds usually possess an enzyme, dehalogenase, that cleaves the carbon-h alogen bond and mediate the metabolic products utilizable. The genus Burkholderia is a group of microbes with versatile metabolic capability. This group of bacteria has been found in various niches. They have been isolated as animal and plant pathogens. B. cepacia and B. cenocepac ia are clinically important species because of their association with cystic fibrosis patients. Some species have been acted as pathogen antagonists and others have been categorized as plant growth-promoting species. Many others have been isolated as important organisms responsibl e for the bioremediation of environmental pollutants. B. xenovorans LB400 has been well studied as one of the most versatile degraders that metabolize polychlorinated biphenyls. My group has been working on the degradation of halogenated alkanoic acids for many years. A Burkholder ia sp. was isolated from soil for its ability to produce a dehalogenase, Deh4a, which degrades 2-haloacids. The enzyme has been purified and the active enzyme has been found to be a dimer of 45 kDa. The gene encoding for this enzyme has been isolated and cloned into Escherichia coli. By means of domain-swap experiments with anothe r dehalogenase, the region responsible for the dimerization of the protein has been identified. Site-directed mutagenesis has also been used to find the residues essential for the structure and activity of the enzyme. A crystal structure of the enzyme has also been resolved. Since haloacetic acids are toxic it would be reasonable to assume the production of the dehalogenase as a detoxifying enzyme and, if necessary, the making of an efflux protein to decrease the availability of the compound inside the cell. During the characterization of the genomi c organization of the dehalogenase gene, we have identified the presence of an associated transporter protein gene. This permease, Deh4p, transported the haloacetic acids into the cell and the gene is located downstream of the dehalogenase gene. The gene encoding for Deh4p has been cloned and sequenced. This permease is 552 residues long and has a putative molecular weight of 59,414 and an isoelectric point of 9.14. Comparative analysis of the primary structure of Deh4p with proteins in the protein family (Pfam) database has designated it as a member of the Major Facilitator Superfamily. It looks like the dehalogenase and the permease genes form an operon responsible for the degradation and uptake of the haloacetates into the cell and converted the harmful chemicals to utilizable substrates. In order to confirm that these two genes were organized as an operon the upstream non-coding region of the dehalogenase gene has been explored. This region has the structural features of typical bacterial housing -keeping genes. Traditional -10 and -35 boxes required for the binding of a sigma-70 RNA polymerase were identified. While the expression of the gene, in multiple copies, in E. coli was minimal, it can be induced more than 200-fold by haloacetic acids in Burkholderia sp. MBA4. The gene encoding Deh4a was isolated in a 1.6-kb EcoR I fragment, which include 832 bp of upstream non-coding sequence. When this upstream sequence was truncated, progressively, and used to drive the expression of a reporter gene, it showed that 100-bp of upstream sequence is sufficient for the haloacetate induction mechanism. DNA fragment containing this 100-bp was amplified and labeled with radioisotope for electrophoretic mobility shift assay. Cell extracts were prepared from cells grown on pyruvate or monochloroacetate. The results showed the presence of retardation complex in cell extract prepared from pyruvate-grown cells and not on monochloroacetate-grown cells. This suggest ed that there is a DNA-binding protein that binds the regulatory region of the dehalogenase gene and prevented it from expressing when there were no haloacetic acids in the medium. This DNA-binding protein is most likely a repressor molecule exhibiting negative effect on the promoter. A proposal has been written and submitted to RGC for purification and characterization of this DNA-binding protein. However, the reviewers would like to see the protein purified and its DNA-binding ability confirmed. In this proposal I would like to ask for funding to purify this DNA-binding protein from MBA4. When the purified protein is available its DNA-binding ability will be confirmed by bandshift assay and the recognition-sequence/region determined by footprinting. The protein will also be subjected to tryptic digest and the digestion products analyzed by tandem mass spectrometry. This would be able to provide some preliminary information of the protein. The immediate goal is obtain sufficient background information on this molecule so that it can be cloned from MBA4 for further characteriza tion. A proposal on the cloning and characterization of this regulatory protein will be submitted to RGC for a GRF grant in 2010. The ultimate aim of the research is to understand the regulatory mechanism for the dehalogenase.


List of Research Outputs

Su X. and Tsang J.S.H. , Identification of a second haloacetic acid transporter in a haloacetate degrading bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . 2010.
Tian R. and Tsang J.S.H. , Mutagenic analysis of the upstream regulatory region of a dehalogenase gene in Burkholderia sp. MBA4, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 76.
Tsang J.S.H. , Kong K.F. and Faan Y.W. , Cloning of a two-component system that affects the expression of a haloacid operon of a Burkholderia species bacterium. , 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 75-76.
Tsang J.S.H. and Tse Y.M. , Mutagenic analysis of the conserved residues of a haloacid permease., FEBS Journal . 2009, 276 supplement 1: 168.
Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.
Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.
Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Tse YM

List of Research Outputs

Tsang J.S.H. and Tse Y.M. , Mutagenic analysis of the conserved residues of a haloacid permease., FEBS Journal . 2009, 276 supplement 1: 168.
Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.


Researcher : Vengatesen T

Project Title: Marine calcifiers and Climate change: response of economically important juvenile benthic calcifiers to ocean acidification
Investigator(s): Vengatesen T, Williams GA, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 02/2009
Completion Date: 08/2010
Abstract:
The increase in global carbon dioxide (CO2) emis sions is not just causing global warming and climate change, but also threatening the marine organisms (Zeebe et al. 2008). CO2 emitted to the atmosphere is being absorbed by the oceans and subsequently causes not only an increase in the partial pressure of CO2 (pCO2) but also a reduction in seawater PH and carbonate ion, called “ocean acidification”. This dramatic change in seawater chemistry is likely to have a large impact on coastal productivity and biodiversity (Fabry 2008), hence assessing the impact of ocean acidification on marine organisms has been identified as a high priority (Iglesias-Rodriguez et al. 2008). The decrease in the saturation state of carbonate ions critically affects the uptake and/or dissolution of calcified shells. Marine organisms has survived large climate and acidification variations in the past, but the projected rates of climate change and ocean acidification over the next century are much faster than experienced by the planet in the past. Recent evidences from a variety of scientific disciplines indicates that calcification rates of many ecological ly important marine organisms are likely to decrease (and dissolution rates increase) in response to ocean acidification by up to 60% within this century (Hunt et al. 2008). However, these estimated rates often do not include other environmental effects (e.g., rising temperature and variable precipitation), nor do they address the effects on different life-stages or organism fitness. Over the past few years, ocean acidification effects have been investigated in very few marine organisms, e.g. corals and phytoplantons, primarily using traditional microscopic-based methods. However, recent advances in molecular biology techniques (e.g. real-time PCR, in-situ hybridization, and proteomics) now allowing us to explore physiological and molecular basis of ocean acidification effects. Majority of sessile marine invertebrates have a pelagic larval stage for dispersal and colonization of new habitats. After a period of development (from minutes to days), larvae enter a competent stage wherein they have developed the ability to attach onto substratum and metamorphose into juveniles. Larval metamorphosis and juvenile development in several species is a dynamic process (completed in few minutes) involving, tissue remodeling, and differentia tion, in addition to numerous biochemical and physiological alterations mediated by differential gene and protein expression. That is why these early-life stages are believed to be highly vulnerable to ocean acidification than their adult counterparts (Albright et al. 2008). Therefore, understanding the effects and underlying physiological and molecular basis of ocean acidificatio n on juvenile development is integral to marine ecology, fisheries biology, aquaculture and environmental biology. Current challenging questions related to ocean acidification effects on marine organisms that are related to this proposal are 1) Can early-life stages (e.g. juvenile s) adapt (e.g. by changing their calcification process) to ocean acidification over the next 100 years? 2) How does a change in calcification rate of early juvenile stages affect their metamorphic success and growth performance? and 3) How is the larval-juvenile-adult transition process mediated at acidified seawater? Answers to these questions will have far-reaching implications for fishery science, on-shore traditional aquaculture, and modeling and monitoring technology. Therefore, in the first part of this project, the effects of ocean acidification on the calcification rates of juvenile marine calcifiers will be quantitatively measured using controlled laboratory experiments. Calcified shells of marine calcifiers consist of both organic matrix materials (primarily proteins) and inorganic crystalline substances (primarily CaCO3). In fact, proteins in mineralized shells play a key role in the growth of shells and also determine the physical characteristics of shells. Besides these integral shell-proteins, calcium transport proteins (e.g. calreticulin), ion-transport membrane proteins, and signal transduction proteins are also all involved in shell formation and growth (“calcification process”). Analysis of expression response of all these proteins to ocean acidification is very crucial for our understating of organisms adaptat ion to present and predicated climate change scenarios. Recently, proteomics technology has emerged to be a highly useful tool to study protein expression pattern in whole organisms at a particular developmental stage or time (Carpentier et al. 2008). Recently, this tool has been successfully applied to marine samples (Thiyagaraja n and Qian 2008). Using similar methodology, here we will test the hypothesis that effects of ocean acidification on juvenile development are mediated through differential expression of proteins associated with calcification, metamorphosis, and stress tolerance. We are confident that this new approach will allows us to determine how juvenile stages of various marine benthic organi sms are able to biochemically cope and respond to these emerging new environmental stressors. It can also show the degree of variability in protein expression (“proteome plasticity”) to ocean acidification. Our primary objectives are: • To determine the effects of ocean acidification on juvenile stages (growth, survival, and calcification) of the economically important marine benthic organisms, and • To identify key similarities and differences in proteins relevant to calcification and/or ocean acidification stress in diverse benthic organisms (molecular mechanisms) by proteomics technology. References Albright R, Mason B, Langdon C (2008) Coral Reefs 27: 485–490 Carpentier SC, et al. (2008) Mass Spectrometry Reviews27:354–77 Fabry (2008) Science 320: 1020–1022 Hunt BPV, et al. (2008). Progress in Oceanography 78: 193–221 Iglesias-Rodriguez MD, et al. (2008) Science 320: 336–340 Thiyagarajan V, Qian PY (2008) Proteomics 8: 3164-3172 Zeebe RE, et al. (2008) Science 321: 51–52


Project Title: Physiological and molecular respon ses of the Pacific oyster larvae to ocean acidification at warm and low-saline seawater: Immediate and latent effects
Investigator(s): Vengatesen T
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To reveal the impacts of increasing pCO2, temp erature extremes and high precipitation (singly and in combination) on larvae of the commercially important shellfish; 2) To determine the long-term consequences of larval exposure to increased pCO2; 3) To test the hypothesis that exposure of larvae to increased pCO2 during mid-su mmer in Hong Kong (elevated temperature and low-salinity) would greatly negate larval metamorphic success and thus fishery; 4) To clarify the mechanisms underlying the observed physiological and ecological effects with the application of proteomics technology.


Project Title: Climate change effects on larval metamorphosis: lessons from biomineralization
Investigator(s): Vengatesen T, Shih K, Williams GA, Dudgeon D
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2010
Abstract:
The life cycle of many marine organisms includes two major stages: swimming larval and benthic (attached on hard/soft substrate) adult stage. After a period of time or attaining a physiological competency, the pelagic (swimming) larvae select a suitable habitat/substra te based on substrate properties, attach on it and then metamorphose into benthic adults (reviewed in Thiyagarajan, in press; See Fig. 2). This pelagic-benthic transition (henceforth referred to “larval metamorphosis”) is perhaps the most crucial, challenging, rapid process, involving intensive biomineralization (a process that form CaCO3 shell) and is therefore, energetically exp ensive. Larval biomineralization is one of the emerging interdisciplinary studies that examines biomaterials such as shells and skeletons produced by larval forms of marine organisms and the processes that lead to the formation of these hierarchically structured organic-inorganic composites. The biomineralization process during larval metamorphosis is not caused by adventitious precipitation; instead, it is highly regulated in a species specific manner (Gower 2008). As a consequence of natural environmental changes (e.g. rainfall), coastal regions are frequently becoming undersaturated with respect to carbonate ions, aragonite and calcite and consequently they are becoming alarmingly vulnerable to CaCO3 shell forming larvae (Findlay et al. 2009, O’Donnell et al. 2009, our studi es). Within this century, human activates (i.e. increasing CO2) are expected to exacerbate this carbonate chemistry variability (CCV). This swing in carbonate chemistry, here termed as “ocean acidification”, is relatively new to scientists and has quickly become part of global climate change issues (reviewed in Doney et al. 2009). Although this research field is rapidly advancing our knowledge, much of the available information is concerned with (1) adult organisms (rather than their larvae), (2) temperate species (subtropical climate is often neglected), (3) corals and planktonic organisms (with only few studies on calcifying shellfish), (4) calcification rates (as opposed to mechanism and biomineralization aspects), and (6) open ocean (as opposed to coastal waters) (e.g. Dupont & Thorndyke 2009). Nevertheless, the majority of these studies highlight the fact that CCV impacts are species-specific (Miller et al. 2009), larvae are more sensitive to CCV than the adults (Kurihara et al. 2009), biomineralization and skeletal structures are impaired by CCV (Cohen et al. 2009). As biomineral precipitation depends on their saturation levels, any decrease in carbonate saturation due to climate change or natural environmental change is expected to affect the ability of larvae to build their CaCO3 shells. There is an urgent need to examine this hypothetical correlation between larval metamorphosis and CCV. One of the main questions that remain to be answered is whether changes in CCV lead to significant differences in biomineralization when the magnitude of these cha nges is much smaller than the large fluctuations in CCV that occur at the site of biomineralization? Larvae of intertidal organisms (e.g. oysters and barnacles) appear very tolerant to a wide range of CCV, i.e. growth rate and developmental pattern are unaffected. Our recent work (fully funded by our ongoing HKU seed grant and partially by just awarded GRF grant) suggests, however, that physiological quality, metamorphic rate, expression of several metabolic enzymes and metamorphic success are reduced in carbonate regimes near or below aragonite saturation levels ( <Ωarag;; this level is expected in 2100 due to climate change or during heavy precipitation in summer months in Hong Kong). In such scenarios, stressed larvae ten d to uptake more CaCO3, which may impose significant costs. We, therefore, hypothesize that <Ωarag will affect larval biomineralization sequence and composition during metamorphosis, possibly through eliciting energetically costly biochemical and physiolo gical responses. According to our preliminary data, the decreasing Ωarag decreases the protein synthetic capacity and biochemical energy available for larval metamorphosis, and consequently impairing their ability to select the right substrate for attachment and metamorphosis. Therefore, we predict that the effects listed above may be due to efforts of larvae to maintain relativel y natural aragonite and/or calcite precipitation rates (biomineralization) with increased effort to cope with decreasing Ωarag . In this proposal, we will test this hypothesis using the commercial barnacle (Balanus amphitrite) by exposing their larvae to various treatments mimicki ng natural and projected carbonate chemistry regimes in Hong Kong’s coastal waters. The X-ray diffraction (XRD) microscopy is a useful technique for investigating the biomineralization process in larvae. Recently, we have been successfully using XRD to trace the composition of biominerals and their precipitation rate during larval development and metamorphosis in barnacles, green mussels and oysters (XRD patterns of swimming and metamorphosed larvae are shown in Fig. 1). This pioneering work started providing us new insight into the possible mechanisms of larval biomineralization. Through this proposal, we would proceed further to investigate the effect of CCV on the development of calcium carbonate polymorphs. Since biomineralization is genetically controlled, we hypothesize that the mineralization sequence may not be altered; however, the rate of biomineralization and the rate of mineralogical change could be affected. Since this technique (XRD) allows analysis of sample with a relatively small quantity (Medaković 2000), it would be a convenient method to detect the calcium carbonate polymorph dynamic in larval exoskeleton during their metamorphosis. To achieve our ultimate goal of understanding the causes and effects of climate change on larvae, it is essential to understand what happens to them during larval metamorph osis at biomineralization level. Also, our preliminary data and link with a crystallographer in our engineering department are tempting us to examine the larval biomineralization response to climate change. This seed grant project is designed to generate preliminary data to examine the effects as well as the mechanisms through which biomineralization in settling larvae of the commercially important and a model barnacle species, B. amphitrite, respond to environmental/climate change. Our primary objective of this proposal is to study the exceptional crystalline properties of larval CaCO3 shell, to character ize climate change variables that control their formation and composition to search for fundamental mechanisms used by early life stages of marine organisms to ongoing environmental/climate change. Specifically, 1. To determine larval metamorphic success under changing carbonate chemistry regimes (CCV) driven by natural and anthropogenic activities in coastal regions, larval attachment rate and response to natural substrates will be examined using choice bioassay method, 2. To determine larval biomineralization sensitivity/response to CCV, sequential changes in biomineral composition and their precipitation rates during larval metamorphosis will be examined using XRD.


List of Research Outputs

Li H., Vengatesen T. and Qian P.Y., Response of cyprid specific genes to natural settlement cues in the barnacle Balanus (= Amphibalanus) amphitrite , Journal of Experimental Marine Biology and Ecology . 2010, 389(1-2): 45-52.
Sun J., Zhang Y., Vengatesen T. , Qian P.Y. and Qiu J.W., Protein expression during the embryonic development of a gastropod, Proteomics . WILEY-VCH Verlag, 2010, 10(14): 2701-2711.
Vengatesen T. , A review on the role of chemical cues in habitat selection by barnacles: New insights from larval proteomics, Journal of Experimental Marine Biology and Ecology . 2010, 392: 22-36.
Vengatesen T. , Larval proteomics: a novel approach to study the effects of ocean acidification at molecular level, South China Sea Institute of Oceanology, Chinese Academy of Sciences (CAS), Guangzhou, on September 13th to 14th, 2009 . 2009.
Vengatesen T. , Lau S.C.K., Mandy T., Zhang W. and Qian P.Y., Monitoring Bacterial Biodiversity in Surface Sediment Using Terminal Restriction Fragment Length Polymorphism Analysis (T-RFLP): Application to Coastal Environment , In: A. Ishimatsu, Lie,H.J. , Coastal Environmental and Ecosystem Issues of the East China Sea . Japan, TERRAPUB and Nagasaki University, 2010, 151-163.
Vengatesen T. , Tsoi M.M.Y., Zhang W. and Qian P.Y., Temporal variation of coastal surface sediment bacte rial communities along an environmental pollution gradient, Marine environmental research . 2010, 70(1): 56-64.
Zhang Y., Sun J., Xiao K., Arellano S.M., Vengatesen T. and Qian P.Y., 2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans , Journal of Proteome Research . American Chemical Society, 2010, In press.


Researcher : Wai TC

Project Title: Stock and Ecological Status of Echinoderms in Hong Kong: Evaluation of Effectivenes s of Marine Protected Areas using Sea Urchins as Model Organism
Investigator(s): Wai TC, Ng WC, Leung KMY, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: Environment and Conservation Fund
Start Date: 04/2008
Abstract:
To conduct a comprehensive literature review of the diversity, abundance, distribution and habitat preference of echinoderm species in the Hong Kong marine environment; to conduct underwater surveys to investigate the diversity, abundance, distribution and habitat preference of commercially exploited species (Anthocidaris crassispina), and other urchin species in rocky, coral and sandy habitats; to conduct an ecological study to test the hypothesis that the number of size classes (i.e. size range) and abundance of urchin populations within MPAs are higher than those unprotected outside MPAs.


Project Title: Food source utilization of groupers (Serranidae: Epinephelinae) in rocky communities in Hong Kong: the significance of trophic subsidies to top predators
Investigator(s): Wai TC, Williams GA
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 01/2009
Abstract:
Hong Kong lies on a continental shelf with mean water depth < 20m and is characterized by rocky coasts and numerous rocky islands (> 200). The long and complex coastline of Hong Kong supports a wide range of marine habitats, from soft shores at stream mouths to rocky intertida l/subtidal and coral communities, to offshore, soft-bottom communities. These habitats support a diverse fish fauna and more than 300 reef fish species have been recorded in rocky and coral communities (Sadovy and Cornish 2000). The distribution, abundance and biodiversity of fish in various marine habitats have been well-documented in recent years (Leung 1994, Leung et al. 1997, Cornish 2000a and b, Sadovy and Cornish 2000, Lam 2002, Leung 2003, Liu 2003, Qiu 2005, Situ 2007, Fok 2008) although the biology and ecology of most reef fish species are still poorly understood. Among the reef fish species in Hong Kong, many studies have focused on commercially important grouper species (Serranidae: Epinephelinae; e.g. reproductive biology, habitat assoc iation, social structure, etc; Chan and Sadovy 2002, Liu and Sadovy 2001, 2004a, 2004b, 2005, Chan unplubl) of which there are 20 species from five genera reported in Hong Kong waters. Given that heavy fishing pressure has removed most of the larger groupers (with maximum total length, TL >50cm), and that the value of live reef fish for food in local markets continues to grow (Sad ovy 1997), only relatively small species (max. TL <30cm) such as Cephalopholis boenak, Epinephelus fas ciatomaculosus, E. merra, and E. quoyanus are still commonly found in Hong Kong (Liu and Sadovy 2005, Chan unplubl). In order to conserve the remaining grouper species and manage a sustainable fish stock, in addition to studies on the population structure and reproductive biology, studies on the trophic status of fish assemblages and their associated habitats are needed to provide information on how energy flow within and between habitats will affect these fish populations (Darnaude et al. 2004, Darnaude 2005). Most species show some plasticity in their diets, which are affected by many biological and physical factors such as body size, season and habitat/region (Kulbicki et al. 2005). Although grou per species inhabiting rocky and coral habitats are presumed to be predators (Sadovy and Cornish 2000), the ontogenetic and spatial/temporal variation in prey consumption of local groupers are not known. It is hypothesized that local species will show ontogenetic shifts in diets as do other grouper species (Linde et al. 2004, Machado et al. 2008). Juvenile groupers may mainly consume small herbivores and detritivores (e.g. worms, fish and crustaceans), whilst adult groupers may rely more on large prey, which are mainly predators (e.g. cuttlefish, squids, predatory fish and crabs). The relative importance of these different trophic linkages which support grouper populations are, therefore, likely to vary with fish size. As Hong Kong experiences a monsoonal climate, the supply of food sources and the relative importance of autotrophic and detrital pathways are temporally variable on rocky coasts. In most food webs, detritus is an important energy and nutrient source for organisms via the detrital pathway, as most primary production is not consumed and is recycled and returned to the environment as detritus (Wetzel, 1995; Moore et al., 2004). Recently, the importance of detrital pathways in driving local rocky intertidal and subtidal communities has been explored using dual stable isotope ratios and fatty acid signatures as dietary tracers (Wai et al. 2008). Feeding guilds at lower trophic levels such as deposit-feeders, suspen sion-feeders and gastropod and echinoid grazers generally depend on autotrophic sources but rely much more on detrital pathways during the summer monsoon, when the availability of terrestrial-, benthic algal- and phyto-detritus peak (Wai et al. 2008). Whilst factors influencing the structure and seasonality of rocky communities in Hong Kong have been investigated (e.g. Kaehler and Williams 1996, Wai and Williams 2006, and references therein), little is known about the importance of seasonal changes and bottom-up effects of these detrital sources on production of consumers at higher trophic levels (e.g. groupers) in local rocky subtidal food webs. As only small grouper species (e.g. Cephalopholis boenak with maximum total length < 30cm) are still abundant in Hong Kong (Liu 2003, Liu and Sadovy 2005), it is hypothesized that small prey which rely on detrital pathways will be more im portant in supporting the remaining grouper populations. This project will investigate the pathways by which organic materials enter the higher trophic level of food webs in rocky communities and will elucidate the relative importance of exogenous (episodic supply of detritus) and endogenous (autotrophic) organic sources in local marine ecosystems. The main objective is to investigate the spatial and temporal variation in energy utilization of higher trophic level species, specifically grouper species in Hong Kong. This project will therefore: I. identify the potential feeding guilds consumed by local groupers; II. determine the ontogentic, spatial and temporal variation in the relative contri bution of different organic sources to groupers; III. reveal trophic pathways utilized by groupers in rocky communities. Ultimately, this project will identify the possible trophic pathways of detrital sources ut ilized by the prey of predatory fish in rocky habitats and highlight the potential importance of trophic subsidies (i.e. episodic supply of detritus) to higher trophic levels in Hong Kong marine ecosystems. This knowledge of energy transfer between and within habitats can be used to inform environmental conservation and management models of Hong Kong’s marine ecosystem. References cited: Please see additional information attached.


List of Research Outputs

Leung K.M.Y. , Wai T.C. , Chan K.Y. and Lau C.P. , Eutrophic waters can serve as nutritious "soup" for the predatory gastropods: a direct botton-up ecological effect, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.


Researcher : Wan JMF

Project Title: Effects of tumor necrosis factor-[alpha]TNF-[alp ha] on cyclins and related cell cycle proteins expressions in human tumor cell lines as determined
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 07/1995
Abstract:
To investigate: a) the effect of TNF on cyclins: D, E, A, B expression by flow cytometry; b) the effec t of TNF on P21, PCNA expression by cytometric studies; c) the effect of TNF on tumor cell lines proliferation and apoptosis studied by flow cytometry.


Project Title: The role of free radicals and antioxidants in motor neuron degenerative disease
Investigator(s): Wan JMF, Vacca-Galloway LL
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 07/1995
Abstract:
There are increasing evidence indicating the involveme nt of free radicals damage in many chronic diseases such as Parkinson's disease, Alzheimer's disease and neurondegenerative disease. By using a motor neuron degenerative disease mouse model, to investigate the roles of free radicals in the disease process and investigating whether antioxidants such as vitamins E and C can be any therapeutic use by naturalizing the free radicals.


Project Title: The effects of antioxidants on small cell lung cancer cell line, NCI-H446
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1995
Abstract:
Lung cancer is almost certainly the most common cancer in the world today. Over the past several years , work has focused on characterizing the prevention, inhibition and regression of lung cancer by [beta]-carotene, vitamin C and vitamin C which act as antioxidants. This study aims to investigate the antiproliferative potential of [beta]-carotene and retinoids by flow cytometry technology. The data will help us to understand how antioxidants prevent lung cancer formation and progression.


Project Title: The effects of different dietary fatty acids on the development of mammary tumors in female fischer 344 rats
Investigator(s): Wan JMF
Department: Zoology
Source(s) of Funding: Other Funding Scheme
Start Date: 09/1995
Abstract:
Exciting evidences demonstrated that the quality of dietary fatty acids, especially W-6 and W-3 polyunsatura ted fatty acids affect the development of cancers such as the colon, breast, and prostate. This project aims to investigate the effect of saturated, monosaturated W-3, and W-6 polyunsaturated fatty acids on breast cancer cells proliferation by using flow cytometry technology. The data in this study will help us understand the mechanisms involved in more depth.


Project Title: Molecular Structural Determination of Protein-bound Polysaccharide peptide (PSP) isolated from the Chinese Medicinal Mushroom Coriolus versicolor (Cov-1)
Investigator(s): Wan JMF, Sze KH, Che CM
Department: Zoology
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 05/2006
Abstract:
Purpose: The goal of this project is to determine the molecular structure of Cov-1 PSP molecule dervies from the Chinese Medicine mushroom Yun Zhi. Key Issues: Polysaccharide peptide (PSP) isolated from the mycelia of fungus Coriolus versicolor (Cov-1 str ain) or Yun Zhi is Chinese Medicine best known for its anticancer and immunomodulatory properties. PSP is classified as a biological response modifier (Ng TB 1998 review) with the ability to induce gamma-interferon, intelerukin-2 production, T-cell proliferation in cancer patients. A small peptide with a molecular weight of 16-18 kDa originating from PSP has been produced with antiproliferative and antitumor activities (Yang et al 1992). We have recently published the cellular and molecular detailed cell death induction pathways of PSP on human leukemic cells by flow cytometry (Yang &Wan 2005, Hui and Wan 2005) and cDNA arrays (Zeng, Leung &Wan 2005). The ability of the Cov-1 PSP to distinguish cancerous cells from non-cancerous cells as recently determined by us (Yang & Wan 2005) and previously by others (NT 1998 review), indeed suggesting its uniqueness potential in its development into anticancer agent. Cov-1 PSP possesses a molecular weight of approximately 100 kDa. The polysaccharide moiety is a heteropolysaccharide made up of monosccharides with alpha-1, 4 and beta-1, 3 glucosidic linkages consisting of glucose, glactose, mannose, xylose, arabinose and trace amount of rhamno se (NT 1998 review). The polypeptide unit contains glutamic and aspartic acids as the abundant amino acids. PSP is presently used as over-the-counter dietary health supplement with multiple health claims such as anti-cancer, anti-inflammatory, antioxidant, anti-allergic and ant i-viral. Our preliminary work on separation and purification of PSP by HPLC technology has identified two factions: a small molecular fraction of < 5000 Da and a macro-molecular fraction of > 5000 Da. The former fraction exhibited anticancer effect onhuman leukemia and the latter fraction exhibited immunomodulatory effect on healthy normal human T-lympho cytes. Despite the promising potentials of PSP, pharmaceumatical industry is not willing to invest into its therapeutic development unless the molecular structural information is apparent. It is urgent to identify the molecular structure of the PSP molecules as soon as possible since this unqiue Cov-1 strain medicinal mushroom exh ibits most promising anticancer and immunomodulatory properties. The Cov-1 PSP strain is currently in Phase III clinical testing for anti-cancer properties in China with sucessful outcomes. Up-to-now, there are no clear structural determination of the PSP parent molecule and its fractions. The present propoal thus sought to reveal the molecular structure of PSP. Issues to be addressed: Additional experiments are also required to more thoroughly assess the molecular structure of the compounds that are responsible for the immunomodulatory effect and that which posses anticancer activities. Purpose of this proposed project: The goal of this project is to determine the structure of Cov-1 PSP molecule by carrying out the following objectives: 1. to purify fractions of PSP by DEAE Anion-exchange HPLC system 2. to elucidate the molecular structure of PSP by spectroscpic analysi s, NMR and/or X-ray crystallograpghy. We believe that the structural determination of the molecular structure of PSP is urgently needed as to provide important insight into its distinct functions/roles in treatment of cancer and infectious diseases. References Cited: Yang MM et al (1992). The anticancer effect of a small polypeptide from Coriolus versicolor. Am J Clin Med 20: 221-32. Ng TB (1998). A review or research on the protein-bound polysaccharide PSP from the mushroom Coriolus versiolor. Gen Pharmacol 30: 1-4. Zeng F, Leung F and Wan JMF (2005). Molecular characterization of Coriolus versi color in human promyelotic leukemic HL-60 cells using cDNA microarray. In J of Oncology 26: 10-16. Hui K.P.Y& Wan JMF (2005) Induction of S phase cells arrest and caspase activation by polysaccharide peptide (PSP) isolated from coriolus versicolor enhanced the cell-cycle-dependent activity and apoptotic cell death of Doxorubicin and Etoposide but not Cytarabine in HL-60 cells. Oncology Reports. 14(1): 145-165. Yang X and Wan JMF (2005). The Cell Death Process of the Anticancer Agent Polysaccharide-peptide (PSP) in Human Promyelocytic Leukemic HL-60 Cells. Oncology Reports 13(6): 1201-1221.


Project Title: The 5th International Medicinal Mushroom Conference Polysaccaropeptide of Coriolus versicolor Enhances the Anticancer Activity of Camptorhecin (CAM) on Human :eukemic HL-60 cells
Investigator(s): Wan JMF
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 09/2009
Completion Date: 09/2009
Abstract:
N/A


List of Research Outputs

Ding W.J., Yan S.L., Zeng Y.Z., Li W.H., Duan A., Zheng T.E., Liu M., Tan C.E., Teng X. and Wan J.M.F. , Insufficient Activity of MAPK Pathway Is a Key Monitor of Kidney-Yang Deficiency Syndrome, The Journal of Alternative and Complementary Medicine . 2009, 15(6): 653-660.
Lee C.L. , Jiang P. , Sit W.H. , Yang X. and Wan J.M.F. , Regulatory properties of polysaccharopeptide derived from Coriolus versicolor and its combined effect with ciclosporin on the homeostasis of human lymphocytes., Journal of Pharmacy and Pharmacology . 2010, 62(8): 1028-36.
Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Wan J.M.F. , Sit W.H. and Yang X., Polysaccharopeptide of Coriolus versicolor enhances the Anticancer Activity of Camptothecin (CPT) on Hum an Leukemic HL-60 Cells, The 5th International medicinal Mushroom Conferen ce . 2009, 691-702.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.
Zhong W. , Sit W.H. , Wan J.M.F. and Yu A.C.H. , Sonoporation-induced apoptosis and cell-cycle arrest: initial findings, International Symposium on Therapeutic Ultrasound . 2010, D3-1.


Researcher : Wan LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.


Researcher : Wang M

Project Title: Preventive potential and mechanism of fruit phytochemicals on the formation of mutagenic heterocyclic amines
Investigator(s): Wang M
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 09/2007
Completion Date: 08/2009
Abstract:
To identify potent inhibitors for HA formation from pineapple and elderberry extracts using chromatog raphic and spectroscopic methods and to clarify whether their intervention can really lower overall mutagenicity in meats; to tentatively clarify the roles of several phenolic compounds in the formation of HAs and to elucidate the detailed inhibitory mechanisms involved.


Project Title: Natural tyrosinase inhibitors as skin whitening agents
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Fund Internship Programme
Start Date: 10/2007
Abstract:
The basic aim of this study is to develop patentable tyrosinase inhibitors (purified compounds, standardi zed concentrated plant extracts) from edible and Chinese medicinal plants, and evaluate their appliction as skin whitening/lightening agents in cosmetic products.


Project Title: Natural Phenolics for Ameliorating Carbonyl Stress
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 04/2008
Completion Date: 09/2009
Abstract:
Non-enzymatic modifications of proteins have been implicated in the pathogenesis of diabetes, atherosc lerosis, and neurodegenerative diseases as well as in normal aging. The modifications can arise from direct exposure to reactive oxygen related species, chlorine, nitrogen species and from reactive with low molecular weight reactive carbonyl compounds, which originate from a multitude of mechanistically related pathways, like glycation, sugar autoxidation, lipid peroxidation and uv-photodamage. The accumulation of various reactive carbonyl species derived from either carbohydrate or lipids, as well as their subsequently induced protein modifications is proposed to constitute a state of “carbonyl stress”. It’s well known that a group of dicarbonyl compounds, including 3-deoxyglucosone (3-DG), glyoxal (GO) and methylgoxal (MGO) will be formed in Maillard reaction (glycation). The increased electrophilicity of these 1,2-dicarbonyl compounds results in their relatively fast reactions with amino, sulfhydryl and guanidine functional groups of intracellular and extracellular proteins. Lipoxidation mainly generates a burst of unsaturated aldehydes, such as 4-hydroxy-trans-2-nonenal (HNE), acrolein (ACR), and malondialdehyde (MDA). Meanti me lipoxidation is also known to produce GO. In contract to glycation-related carbonyl compounds, less is known about protein modification by lipoxidation-derived RCS. However a large body of evidence indicates that many of the effects of vascular dysfunction on cardiovascular diseases are mediated by lipid-derived RCS and the emerging role of lipid-derived RCS in hyperglycemia and in development of complication of diabetes is now well documented. Recently, the involvement of lipid-derived RCS as products and propagators of oxidative damage in neurodegenerative diseases, mainly AD, is also becoming elucidated. Under carbonyl stress, not only advanced glycation end-products (AGEs) derived from carbohydrate s but also advanced lipoxidation end-products (ALEs) derived from lipid accumulate in parallel. AGEs and ALEs might be merely end-results of protein structural modifications, alternatively they might play an active role in the development of various age-related diseases. In addition, compared to free radicals, RCS are stable and can diffuse within and even escape from cell and attack target far from the site of the original forma tion. Therefore they are not only end-products of glycation/lipoxidation, they also act as “second cytotoxic messengers”, induce different aspects of cellular stress. Thus there is a need to develop strategy to deal with carbonyl stress, to ameliorate various age-related diseases. A very limit number of inhibitors of cellular reactive carbonyl species have been identified to date and their therapeutic potential are recognized only recently. Some inhibitors interfere with the reaction by trapping carbonyl compounds, while others act merely as antioxidants and transition metal chelators. As free radicals and oxidation are known to be in the process of glycation and lipoxidation, it’s not a surprise that antioxidants may be effective in in vitro assays. However it’s questionable of the effects of antioxidant against carbonyl stress, AGE and ALE formation in the real biological system. As an example, the capability of pyridoxamine (PM) to delay development of diabetic complications in animal models has been well documented. The biological effects of PM, notably its inhibition of development of renal and vascular disorders in both diabetic and Zucker rats, may be chiefly attributable to its function as an inhibitor of AGE/ALE formation through a carbonyl-tr apping mechanism. Although PM is known to be an antioxidant, it has been shown to be incapable of preventing oxidative loss of linoleate or arachidonate in phosphate buffer, even at 1mM concentration. On the other hand, it can significantly inhibit the formation of CML, CEL and MDA-Lys, and of HNE-Lys (2-hydroxylhexanal-lysine co mplex) in the presence of ribonuclease, suggesting that it does not function primarily as an antioxidant. It is an attractive hypothesis that antioxidation may not be the dominant action mechanism of other compounds found to have inhibitory activity against AGE formation. In addition, numerous clinical trials have failed to provide conclusive evidence for the efficacy of antioxid ant therapy in several chronic diseases, questioning the effects of antioxidant against carbonyl stress. Thus the chemical agents which can directly trap reactive carbonyl species will be more promising and have real clinical application. Natural products have been shown to be safer for human consumption than synthetic compounds. In this regard, some plant extracts have been evaluated for their inhibitory effects on reactive carbonyl induced protein structural modification. However, only a very limited number of natural produ cts have been found to have reactive carbonyl-trapping capacity. Lo et al. in 2006 reported the MGO trapping reaction of green tea catechins and black tea theaflavins under simulated physiological conditions. The reaction products of EGCC and methylglyoxal were separated by chiral column and the structures were confirmed by 2D-NMR analysis. This study provided the first solid evidence that certain groups of phenolic antioxidants can directly trap reactive carbonyl species, and com pelled a reconsideration of the anti-glycation mechanism of phenolic antioxidants. The findings suggested that certain phenolics possessing dual mechanisms of action, namely antioxidation and RCS scavenging, maybe potentially more effective in preventing reactive dicarbonyl compo unds induced protein glycation. Our recent research also found procyanidin B2 can effectively trap MGO, with better trapping capacity than aminoguanidine (AG), the first AGE inhibitor explored in clinical trials. Careful examining the structures of catechins, procyanidin B2, we found they contained unique nucleophilic moiety which might contribute to their MGO trapping capacity. However little is known whether other types of phenolic compounds can trap MGO (an intermediate carbonyl compound produced during glycation) or not, and whether phenolic compounds can direct trap lipoxidation-related unsaturated carbonyl compounds or not. All these demand further scientific clarification. The basic aims of this study are to elucidate the RCS trapping capacities of various phenolic compounds, evaluation their trapping mechanism through detection of conjugated compounds and structural elucidation, and evaluation of their effects on the formation of AGEs and ALEs. In brief, the study seeks to make a significant contribution to the amelioration and prevention of several chronic diseases by discovery of specific phenolic RCS-trapping agents.


Project Title: Citrus Flavonoids as Food Additives for Reducing the Formation of Hazardous Substances in Processed Food Products
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 12/2008
Completion Date: 12/2009
Abstract:
A large portion of our disposable income is spent on food, only second to housing. Foods provide humans essential nutrients for growth and health maintenance. On the other hand, it is estimated that up to 50% of cancers are diet related. The potential harmful effects of foodborne toxicants have been well recognized. In addition to the well-known hazardous substances such as pesticides, heavy metals, antibiotics, environmental contaminants in foods, a group of compounds including heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), reactive carbonyl species (RCS), advanced glycaion end products (AGEs) and akrylamide might also contri bute to the mutagenicity, carcinogenicity and other toxic effects of certain food products. These compounds can be regarded as by-products of food heat processing, such as roasting, baking, broiling and frying, which are essential for food safety and improvement of organoleptic properties of foods. Further studies showed that fund amental food components including carbohydrates, amino acids, proteins and lipids undergo degradation, oxidation, caramelization and/or interact through Maillard reaction and various adduction reactions, giving rise to these toxicants. Mutagenicity/carcinogenicity of many of these compounds has been established. The good side is that there have been continuous research approaches aiming to reduce the formation of these compounds in foods. In the past, a combination of temperature, pH, cooking time, water activity and precursor compositions/concentration s were central determinants for the final toxic products formed. In other words, these have been targets for developing inhibitory strategies. However, the viewpoint has changed ever since the growing popularity of incorporating various food additives, plant extracts or tissues in to different cuisines and the realization of the importance of natural antioxidants in food systems. A variety of synthetic and natural agents have been examined using both simple chemical model and real food systems. The major pitfall is that most of these inhibitors were tested only for their activity against the formation of a very limited number of genotoxic substances. Consid ering the fact that the above mentioned classes of toxicants are formed from similar primary food components and that the reaction pathways, though differ, may be concurrent under many food processing conditions, it is believed that intervention with one of these pathways would have significant impact on the chemistry of others. This led us to initiate the research effort to ident ify natural additives which are active against the formation of a wide spectrum of toxic compounds formed during of thermal preparation of foods, thus minimizing the overall toxicity load of the final food products. Our recent basic research work supported by RGC has demonstra ted that certain phytochemicals can significantly inhibit the formation of mutagenic HAs in foods. One of them, naringenin, which widely occurs in citrus fruits and other plants such as tomato and apple, was found to be especially potent. Our mechanistic study has brought a new insight into the mechanism of inhibition by natural phenolic compounds, whose inhibitory mechanisms were frequently attributed to antioxidation by others. In other words, we proved that alternative key inhibitory mechanism(s) exist and the findings have been published in several top journals in the field of food science and technology. We currently has got a breakthrough discovery that naringenin probably inhibits formation of HAs, in particular, PhIP (the most abundant HA in foods) by directly trapping RCS which are critical HA intermediates. However, much further research has to be continued to realize our ultimate goal of the project – development of a commercial food additive with inhibitory activity against a broad spectrum of toxic compounds in processed foods. This will include evaluating the effect of potential flavonoids, especially naringenin, on the formation of other types of hazardous substances in foods, identification of synergistic or counteracting phytochemicals in the citrus extracts of interest, processing of by-products from citrus juice production into extracts which, ideally are to be selectively concentrated in favor of the principal inhibitors as well as synergistic components, and finally assessment of the effect of such additive on the sensory properties of the food products examined. It is hoped that commercialization of such natural extract would contribute significantly to reduction in human exposure to food-borne toxicants. The specific aims of this project are: Objective 1: Development of sensitive analytical methods for analysis of PAHs, RCS, akrylamide, and AGEs in model systems and real food products. Objective 2: Preparation of different citrus extracts using differe nt technologies and evaluating the effects of these extracts on formation of toxic substances in processed foods. Objective 3: Development of citrus extract(s) of interest into commercial food additive which is selectively concentrated in favor of potent inhibitors identified.


Project Title: The 237th ACS National Meeting & Exposition Tyrosinase inhibitors from Artocarpus heterophyllus as antibrowning agents for apple slices
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 03/2009
Abstract:
N/A


Project Title: Integrated approaches to evaluate the bioactivities of process-induced novel flavonoid derivatives in thermally processed food systems
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 06/2009
Completion Date: 11/2010
Abstract:
Almost all food items consumed are processed to some extent. Thermal treatment is among the most popular ways of processing. During heating, a complex array of chemical reactions take place which play a pivotal role in determining the quality attributes (sensory, nutritional and safety) of the process foods. While some compounds are destroyed during food processing, many more new compounds might be introduced into the food system. Some of these compounds contribute sig nificantly to the organoleptic properties of foods, such as color and flavor. On the other hand, compounds with various biological activities could also be resulted from the heat-induced reactions. Some of them have been shown to be potential antioxidative and chemopreventive agen ts. In contrast, some are harmful and might pose significant health risks for human beings in the long term. Representative members of such food-borne toxicants include heterocycl ic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), reactive carbonyl species (RCS), advanced glycaion end products (AGEs) and acrylamide. The formation of these compounds involves complex networks of reactions, though many start with fundamental food components such as glucose, amino acids/proteins, and lipids. Other ingredients such as flavonoids may interact with these reactions. Flavonoids, in the broad sense, are virtually universal plant pigments. They are respons ible or partially responsible for the color of flowers and sometimes leaves. When they are not directly visible, they contribute to coloration by acting as copigments. Flavonoids have a common biosynthetic origin and possess the same basic structural element, namely the 2-phenylch romane skeleton. They fall into about a dozen classes depending on the degree of oxidation of the central pyran rings; best known flavonoid skeletons are flavone, flavonol, flavanone, flavan, anthocyanin and chalcone. Most of these skeletons (with the exception of anthocyanin) are quite stable. Flavonoids have been well known for their antioxidant activity. Recently, they have been recognized as a class of natural products which could be utilized to fortify various food products with powerful antioxidants either for health benefits or pure marketing strategy. In addition, flavonoids or plant extracts with high concentration of flavonoids are quite popular as novel food additives for food products to reduce the formation of mutagenic and carcinogenic heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs) and acrylamide by interaction with one key chemical reaction in food science, Maillard reaction. Our former research work has demonstrated that two flavonoids, naringenin and EGCG can significantly inhibit the format ion of mutagenic HAs in foods. Our mechanistic study has also brought a new insight into the mechanism of inhibition of HA formation by flavonoids, whose inhibitory mechanisms were frequently attributed to antioxidation. We curren tly have got a breakthrough discovery that naringenin and EGCG mainly inhibits the formation of HAs, in particular, PhIP (the most abundant HA in foods) by directly trapping Strecker aldehyde, phenylacetaldehyde which is a key intermediate PhIP formation. Novel adducts are formed between the reaction of flavonoids and phenylacetaldehyde. In case of naringenin, inhibition of PhIP formation gave rise to 8-C-(E-phenylethenyl)naringenin and 6-C-(E-phenyletheny l)naringenin in high concentrations. Independent of this, we also discover that phloridzin, a chalcone-type flavonoid and epicatecin, a flavan can effectively trap methylglyoxal, another key Maillard reactive intermediate even at room temperature to form some novel adducts. All these findings suggest that certain flavonoids could directly participate in the Maillard reaction (the reaction between sugar and amino acid/proteins, the most important chemical reaction in food), and consequently lead to the formation of flavonoid derivatives that are structurall y distinct from the parent flavonoids. It is therefore anticipated that these derivatives might have distinctive bioactivities, too. In addition, drastic heat treatment could also cause degradation of flavonoids, thus introducing further potentially bioactive compounds into the food systems concerned. Many of them will likely remain in the food products and be taken into the human body upon consumption of the food products. Ideally, these newly formed compounds could confer beneficial effects, such as enhanced antioxidant, and antimutagenic/anticarcinogeni c activities to human beings. Yet, it is probable that some of these derivatives are toxic. The impact of these thermal treatment-induced derivatives of natural products should by no means be neglected. Surprisingly, this area of enormous significance to food quality remains largely untouched. In the current study, we plan to address the above issues from a multitude of approaches: chemical, molecular pharmacological, and metabolomics approaches. With advanced analytical tools in place, we aim to characterize key thermal treatment-induced derivatives of flavonoids as well as to evaluate their biological activities. Specific objectives of this research work include: 1. Metabolomics approach to evaluate the chemical profile of the selected flavonoids in food system. Isolation and structural characterization of thermal process-induced degradation products of these flavonoids and new derivatives formed from the reaction between these flavonoids with other food ingredients, particularly formed in a few of important Maillard reaction chemical systems (glycine with glucose, phenylalanine with glucose, asparagine with glucose, and tryptophan with glucose). 2. Evaluation of the mutagenicity and toxicity of the newly formed deriva tives (adducts) or degradation products of flavonoids in different Maillard reaction systems. 3. Evaluation of antioxidant and anti-carcinogenic activities of the newly formed adducts. Their selective cytotoxicity in normal versus cancer cells will be examined, and potential anti-cancer mechanisms will be tackled with molecular approaches.


Project Title: American Chemical Society Fall 2009 National Meeting & Exposition Dietary phenolics: New roles in disease prevention and food application
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Development of Novel Skin Whitening Cosmetic Products with Natural Tyrosinase Inhibitors as Key Ingredients
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Innovation and Technology Support Programme (Tier 2)
Start Date: 04/2010
Abstract:
The basic aim of this study is to develop patentable tyrosinase inhibitors (purified compounds, standardized concentrated plant extracts) from Chinese medicinal plants, evaluate their application as skin whitening/lig htening agents in cosmetic products, and develop cosmetic formulas with these novel ingredients as key ingredients. The specific objectives are: Objective 1. To develop a highly purified and concentrated Artocarpus heterophyllus extract, with the overall content of steppogenin, artocarpesin, norartocarpetin, artocarpanone, and isoartocarpesin to reach 20%. Objective 2. To isolate, purify and elucidate the structures of tyrosinase inhibitors from Morus australis root extract and Cudrania tricuspidata twig extract and evaluate their effects on melanin synthesis and cell viability in melan-a cell culture. Objective 3. To formulate Artocarpus heterophyllus extract into real cosmetic products (cream, lotion, serum and paper mask) and test their safety, and efficacy.


Project Title: Establishing a Quality Control Platform for Popular Nutraceutical Products in Hong Kong Market
Investigator(s): Wang M
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Applied Research
Start Date: 06/2010
Abstract:
The term "nutraceuticals" is a combination of the words nutrition and pharmaceuticals, and refers to substances which possesses physiological benefits or provides protection against chronic diseases. Nutraceu ticals may include fortified foods, functional foods, specific diets, genetically engineered foods, herbal products, dietary supplements, and processed foods such as cereals, soups, and beverages. Specific examples of nutraceutica ls are resveratrol from red grape products as an antioxidant, soluble dietary fiber products, such as psyllium seed husk for reducing hypercholesterolemia, broccoli (sulforaphane) as a cancer preventive agent, soy or clover (isoflavonoids) to improve arterial health, and vitamins and minerals for general health management. In recent years, consumers have become more health conscious. The concept of takin g nutraceuticals to promote health and prevent diseases such as heart disease, cancer, osteoporosis, arthritis, and type 2 diabetes mellitus is widely recognized. As a consequence, there has been a rapid increase in the demand for nutraceuticals which has been the major driving force for the development of nutraceutical products to suit the need of different groups of customers. The nutraceutical industry is booming and the sales of for the global nutraceutical industry is over 180 billion USD annually. There are different types and forms of nutraceuticals on the market. As for different commercial purposes, there are different quality control and quality assurance standards. But usually they follow some general rules, the raw materials must be authentic ated, safe to use, with a limit of foreign materials, heavy metals, aflatoxins and pesticides. The pH value, ash contents, moisture contents and particle size should be in a reasonable range. Also the microbiological tests must be passed. The general quality control standards are usually able to be met. But specific standards for nutraceutical products are usually lacking, and this is one of the major challenges that face the nutr aceutical industry. Instrumental methods, especially HPLC (high pressure liquid chromatography) are well known to be good methods for quality control and fingerprinting nutraceutical as well as pharmaceutical products. HPLC coupled with photodiode array detector, MS/MS and ELSD (Evaporative light scattering detector) are suitable for the analysis of various nonvolatile components in nutraceutical products and GC (Gas Chromatography) and GC/MS are good for analysis of volatile compounds, fatty acids and sterols. By careful development and validation, these instrumental methods can be used to systematically control the quality of various nutraceutical products. A recent market research pointed out that based on broad applications and increasing clinical evidence of health benefits and safety of nutraceutic als, the following types of products will likely have the best growth opportunities: soy protein nutrients; lutein, lycopene, omega-3 fatty acids, probiotics and sterol esters which can easily used as functional food and beverage additives; essential minerals calcium and magnesium; herbal extracts, garlic (for improving cardiovasc ular functions), green tea (for cancer prevention and weight loss), bilberry (for eye health), saw palmetto (for benign prostatic hyperplasia) and black cohosh (for postmentopausal symptoms); and the non-herbal extracts chondroitin, glucosamine and coenzyme Q10. In addition, global demand for nutraceutical vitamin ingredients will continue to increase. These products have already been very popular in Hong Kong and Mainland China. Together with classic Chinese healthy foods such as Reishi mushroom, bird nest, these products are the key healthy products in Hong Kong. However, in Hong Kong, we are lacking of quality control procedures and methods for these nutraceutical products, there is no lab which can perform and provide quality control analysis for them although they are very popular products in the market. This is different from the status of traditional Chinese herbal medicines, for which the government has invested a lot of resources to develop quality control procedures and this scheme has been one of major strategies for modernization of traditiona l Chinese herbal medicines. In this project, we want to establish a quality control platform for nutraceutical products. A survey of popular nutraceutical products in Hong Kong will be conducted, and methods will be developed and validated for the quality control of these products. These methods can be adopted by governmental agencies for regulation of nutraceutical products in HK, by local nutraceutical companies for production of high-quality nutraceutical products, and by the commercial testing labs in Hong Kong to provide service to local and international companies in the nutraceutical business.


List of Research Outputs

Chang R.C.C. , Chao J. , Ho Y.S. and Wang M. , Neurodegeneration: the Processes, Hong Kong Medical Journal . 2009, 15(6) Suppl. 7.
Chang R.C.C. , Chao J. , Yu M.S. and Wang M. , Neuroprotective effects of oxyresveratrol from fruit against neurodegeneration in Alzheimer's disease, In: Charles Ramassamy and St é phane Bastianetto, Recent Advances on Nutrition and the Prevention of Alzheimer's Disease, 2010 . Kerala, India, Transworld Research Network, 2010, 155-168.
Chao J. , Lau K.W. , Huie M.J. , Ho Y.S. , Yu M.S. , Lai S.W. , Wang M. , Yuen W.H. , Lam W.H., Chan T.H. and Chang R.C.C. , A pro-drug of the green tea polyphenol (-)-epigallocatechin-3-galla te (EGCG) prevents differentiated SH-SY5Y cells from toxicity induced by 6-hydroxydopamine, Neuroscience Letters . 2010, 469: 360-364.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Neuroprotective effects of methylated resveratrols in an vitro Parkinson's disease model , Society for Neuroscience 2009 . Program No. 144.2: Poster No. G10.
Chao J. , Cheng K.W. , Yu M.S. , Chang R.C.C. and Wang M. , Protective effect of pinostilbene, a resveratrol methylated derivative against 6-hydroxydopamine-induced neuroto xicity in SH-SY5Y Cells, Journal of Nutritional Biochemistry . 2010, 21: 482-489.
Chao J. , Li H. , Cheng K.W. , Yu M.S. , Wang M. and Chang R.C.C. , Resveratrol methylated derivatives as neuroprotective agents in 6-hydroxydopamine-induced SH-SY5Y cells, 5th International Symposium on Healthy Aging . 2010, Page 53.
Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Cheng K.W. , Yang R.Y., Tsou S.C.S., Lo C.S.C. , Ho C.T., Lee T.C. and Wang M. , Analysis of antioxidant activity and antioxidant constituents of Chinese toon, Journal of Functional Foods . 2009, 1: 253-259.
Cheng K.W. , Ou S.Y., Wang M. and Jiang Y., Effects of fruits extracts on the formation of acrylam ide in model reactions and fried potato crisps, Journal of Agricultural and Food Chemistry . 2010, 58: 309-312.
Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.
Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Du Y. , Chu H. , Wang M. , Chu I.K. and Lo C.S.C. , Identification of flavone phytoalexins and a pathogen-inducible flavone synthase II gene (SbFNSII) in sorghum, Journal of Experimental Botany . 2010, 61: 683-694.
Ho C.T., Sang S.M. and Wang M. , Reactive carbonyl species and advanced glycation end-products in foods, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-60 . 2010.
Law Y.K. , Wang M. , Ma D.L. , Al-Mousa F., Michelangeli F., Cheng S.H., Ng M., To K.F., Mok O.Y.F., Ko Y.Y. , Lam S.K. , Chen S.F. , Che C.M. , Chiu P. and Ko B.C.B., Alisol B, a novel inhibitor of the SERCA pump, induce s autophagy, ER-stress and apoptosis, Molecular Cancer Therapeutics . 2010, 9: 718-730.
Li H. , Wu W.K.K., Li Z.J., Chan K.M., Wong C.C.M., Ye C.G., Yu L., Sung J.J.Y., Cho C.H. and Wang M. , 2,3',4,4',5'-Pentamethoxy-trans-stilbene, a resveratrol derivative, inhibits colitis-associated colorectal carcinogenesis in mice , British Journal of Pharmacology . 2010, 160: 1352-1361.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Liu H. , Du Y. , Chu H. , Shih C.H. , Wong Y.W., Wang M. , Chu I.K. , Tao Y. and Lo C.S.C. , Molecular Dissection of the Pathogen-inducible 3-Deoxyanthocyanidin Biosynthesis Pathway in Sorghum., Plant and Cell Physiology . 2010, 51: In Press.
Ma J. , Peng X. , Cheng K.W. , Kong R., Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard Reaction between lactose and phenylalanine, Food Chemistry . 2010, 119: 1-6.
Ma J. , Peng X. , Cheng K.W. , Kong P.W. , Chu I.K. , Chen S.F. and Wang M. , Effects of melamine on the Maillard reaction between lactose and phenylalanine, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-137, poster. . 2010.
Peng X. , Ma J. , Chao J. , Sun Z. , Chang R.C.C. , Tse I., Li E.T.S. , Chen F. and Wang M. , Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption, Journal of Agricultural and Food Chemistry . 2010, 58: 6692-6696.
Peng X. , Ma J. , Cheng K.W. , Jiang Y., Chen S.F. and Wang M. , Grape seed extract fortification leads to bread with stronger antioxidant activity and acceptable quality attributes, Food Chemistry . 2010, 119: 49-53.
Peng X. , Ma J. , Chao J. , Chen S.F. and Wang M. , Protective effects of proanthocyanidins on insulin signaling pathways impaired by methylglyoxal in 3T3-L1 adipocytes, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, 2010, AGFD-162, poster . 2010.
Sun Z. , Peng X. , Liu J. , Fan K.W. , Wang M. and Chen S.F. , Inhibitory effects of microalgal extract on the formation of advanced glycation endproducts (AGEs), Food Chemistry . 2010, 120: 261-267.
Wang M. , Dietary phenolics: New roles in disease prevention and food application. , 238th ACS National Meeting, Washington, DC, United States, August 16-20 . 2009.
Wang M. , Chu I.K. and To T.K.J. , Application of epigallocatechin gallate to prevent DNA interstrand cross-links caused by reactive carbonyl species, 239th ACS national Meeting, San Francisco, CA, USA, March 21-25, AGFD-84 . 2010.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vitamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-85 . 2010.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Wang Y

Project Title: EGFR Ligands in the Chicken Ovary --- How Are They Involved in the Proliferation, Differentiation, and Apoptosis of Ovarian Granulosa Cell?
Investigator(s): Wang Y, Leung FCC
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2008
Abstract:
Although the actions of EGFR ligand and EGFR (EGF network) in mammalian ovary have been extensively studied (Conti et al., 2006), their roles in the ovaries of vertebrates are yet to be fully understood. Using chicken as an experimental model, the proposed project aims to address the following issues: 1) Where and when are EGFR ligands expressed in the chicken ovary? Using real-time quantitative PCR (or semi-quantitative PCR) and in situ hybridization (or immuno-histochemistry), we will examine the expressions of all EGFR ligands during (a) ovarian development, (b) prehierarchal foll icle growth and selection, and (c) rapid growth of preovulatory follicle. This experiment aims to I) provide the complete information on spatio-temporal expression pattern of ovarian EGFR ligand and II) establish a basis to inter pret the roles of EGFR ligand in the ovary. 2) What are the roles of EGF ligands in controlling granulosa cell proliferation, differentiation and apoptosis? Since mature EGFR ligands may have similar biological actions on target cells, this study will investigate their roles, particularly that of EGFR and two EGFR ligands (Epigen and HB-EGF), in granulosa cell prolifera tion, differentiation and apoptosis. a) Roles of EGFR ligand in granulosa cell proliferation, differentiation and apoptosis. In vitro evidences in chickens suggest that exogenous EGF (or TGF-α) stimulates granulosa cell proliferation and prevents its differentiation and apoptosis. However, it remains unclear if both mature and membrane-anchored forms of EGFR ligands are involved in these processes. Over-expression of chicken HB-EGF and Epigen with mutated proteolytic cleavage sites in cultured granulosa cells, together with studies on the roles of recombinant HB-EGF and Epigen, will shed light on this interesting issue. b) Roles of EGFR in granulosa cell proliferation, differ entiation and apoptosis We will knockdown the expression of EGFR by RNA interference to probe or confirm the roles of EGFR and EGFR ligand in the proliferation, differentiation and apoptosis of granulosa cells in the absence or presence of gonadotropins. Meanwhile, the inhibition of EGFR tyrosine kinase activity by Tyrphostin AG1478 will be performed to substantiate these findings. This experiment aims to address: I) whether EGFR is essential for granulosa cell proliferation, differentiation and apoptosis; II) how the EGF network and gonadotropins act in concert to determine the fate of ovarian granulosa cell. 3) Are the expressions of EGFR ligands regulated by gonadotropin and intra-ovarian factors in granulosa cell? To determine whether the EGFR ligand could mediate part of the actions of gonadotropins and local ovarian factors in granulosa cells, the regulation of EGFR ligand and EGFR expressions by gonadotropins (FSH and LH) and intra-ovarian factors (IGF-I, activ in, TGF-β1 and gonadal steroids) will be examined in cultured granulosa cells from prehierarchal and preovulatory follicles.


List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness , The 35th FEBS Congress Molecules of LIfe. June 26-July 1, 2010. . 2010.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-related Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Wang Y

List of Research Outputs

Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning And Characterization Of Chicken Galanin Type I Receptors, Poultry Science . 2009, 88: 122.
Ho C.W.J. , Zhao D., Kwok H.Y.A. , Wang Y. and Leung F.C.C. , Cloning and characterization of chicken galanin type I receptors, Poultry Science Association 98th Annual meeting 2009 Raleigh, North Carolina . 2009, 88 (supplement ): 122.
Wang Y. and Lui W.Y. , A correlation between TGF- b 1-mediated JAM-A downregulation and cell invasiveness, The 35th FEBS Congress Molecules of LIfe. June 26-July 1, 2010. . 2010.
Wang Y. , Li J., Wang C.Y., Kwok H.Y.A. , Zhang X. and Leung F.C.C. , Characterization Of The Receptors For GHRHAnd GHRH-rela ted Peptides: Identification Of A Novel Receptor For GHRH And The Receptor For GHRH-LP (PRP)., Domestic Animal Endocrinology . 2009, 38: 13-31.


Researcher : Williams GA

Project Title: Trophic links between terrestrial and marine ecosystems: the source and fate of detrital materials driving intertidal and subtidal communities
Investigator(s): Williams GA, Dudgeon D, Leung KMY
Department: Ecology & Biodiversity
Source(s) of Funding: General Research Fund (GRF)
Start Date: 10/2007
Abstract:
(1) Determine the spatial and temporal distribution and abundance of allochthonous detrital materials in coastal habitats. (2) Document the spatial and tempo ral variation in the relative contribution of different organic sources to both intertidal and subtidal communities. (3) Reveal the potential trophic pathways of detrital sources between terrestrial and coastal ecosystems.


Project Title: Proteomic responses of the inter tidal limpet, Cellana grata, to environmental stresses.
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2007
Completion Date: 11/2009
Abstract:
The objectives of this proposal are 1. To reveal protein profiles of intertidal limpets, Cellana grata, under extreme environmental stresses during summer low tide conditions; 2. To identify potential protein markers associated with these stresses, and elucidate the possible pathways associated with the stress response. Research Background All around the world, the intertidal zone represents a highly dynamic environmental gradient. During a tidal cycle, organisms living on this gradi ent experience the stable, buffering effects of submersion in seawater and then rapidly changing conditions when uncovered and exposed to hot, drying air (Little & Kitching, 1996). This is especially true for tropical intertidal environments, which are extremely stressful, as marine organisms have to spend part of their lives out of water under the tropical sun (Garrity, 1984). Hong Kong shores experience a monsoonal climate, and as such have a physically harsh environment, varying between cool, dry temperate winters and hot and wet tropical summers (Kaehler & Williams 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams, 1994). This kind of regular death event has not been documented on other tropical shores, although anecdot al records exist. This regular phenomenon indicates the environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. Organisms can tolerate these stressful conditions in a number of ways. If they are mobile, they can move to hide from the sun, living in refuge habitats which are damp and cool (Williams & Morritt, 1995) and timing their activity patterns to avoid stressful periods (Ng & Williams, 2006). Non-mobile species, and those mobile species which cannot find safe refuges, utilize physiological responses to minimize stresses; varying heart rate (Chelazzi et al. 1999), water evap oration (Williams & Morritt, 1995; Harper & Williams, 2001) and haemolymph osmolality (Chan et al. 2006). In extreme cases animals can adopt extreme, last-gasp responses – lifting their shells and opening their opercula to rapidly cool, but with the risk of mortality due to water loss (Williams et al. 2005). The induction and outcome of these behavioural and physiological responses are mainly driven by a series of reactions at the cellular and subcellular level. Knowledge at this level is limited and investigations have mainly focused on measurement of selected stress related proteins. One of the well known examples are the heat-shock proteins (Hsps, Feder & Hofmann, 1999; Lindquist, 1986), which have been widely studied in different taxa, habitats and localities (see Feder & Hofmann, 1999). In local investigations, we have shown species level differences in Hsp expression between limpet species, as well as variation in induction rate and timing (Lai, 2005; Dong et al. unpublished data). Further advances in our understanding of the underlying cellular mechanisms and their interactions, however, are limited by the inability to simultaneously measure multiple proteins. The development of proteomics overcomes this problem, providing a high-throughput analyzing system for rapid measurement and identification of known or unknown protein mixtures (Nunn & Timperman 2007). This allows investigators to determine how organisms are able to biochemically cope and respond to varying environmental stresses through the analysis of the expressed proteome in particular environmental conditions. Proteomics have been extensively applied in questions dealing with anthropogenic stress (e.g. pollution, see López- Barea & Gómez-Ariza 2006), although the utilization of this approach to assess natural environmental stress, particularly in marine systems, is still minor. This study is, therefore, designed to investigate, using a well-studie d and common intertidal limpet, Cellana grata, as a model organism, the proteome expression at different phases of the tidal cycle during stressful, summer spring tides. The study will identify the protein markers and pathways associated with the stress response. We plan future extension of this baseline information to other members of the intertidal community, allowing us to examine interspecific variation with respect to species’ distributions and ecologies. References: Chan BKK, Morritt D, De Pirro M, Leung KMY, Williams GA. 2006. Summer mortality: effects on the distribution and abundance of the acorn barnacle Tetraclita japonica on tropical shores. Marine Ecology Progress Series 328: 195-204 Chelazzi G, Williams GA, Gray DR. 1999. Field and laboratory measurement of heart rate in a tropical limpet, Cellana grata. Journal of Marine Biological Association of U.K. 79: 749-751. Garrity SD. 1984: Some adaptations of gastropods to physical stress on a tropical rocky shore. Ecology 65: 559–574. López-Barea J, Gómez-Ariza JL. 2006. Environmental proteomics and metallomics. Proteomics 6: S51-S62 Harper KD, Williams GA. 2001. Variation in abundance and distribution of the chiton Acanthopleura japonica and associated molluscs on a seasonal, tropical, rocky shore. Journal of Zoo logy 253:293-300 Kaehler S, Williams GA. 1996. Distribution of algae on tropical rocky shores: spatial and temporal patterns of non-coralline encrusting algae in Hong Kong. Marine Biology 125: 177-187 Lai CH. 2005. Heat shock protein expression in limpets on Hong Kong rocky shores. M.Phil thesis. The University of Hong Kong. Hong Kong. Little, C, Kitching, J. 1996. The Biology of Rocky Shores. New York: Oxford University Press Ng JSS, Williams GA. 2006. Intraspecific variation in foraging behaviour: influence of shore height on temporal organization of activity in the chiton Acanthopleura japonica. Marine Ecology Progress Series 321: 183-192 Nunn BL, Timperman AT. 2007. Marine proteomics. Marine Ecolo gy Progress Series 332: 281-289 Sanders BM, Hope C, Pascoe VM, Martin LS. 1991. Characterization of the stress protein response in two species of Collisella limpets with different temperature tolerance. Physiological Zoology 64: 1471-1489 Williams GA. 1994. The relationship between shade and molluscan grazing in structuring communities on a moderately-exposed tropical rocky shore. Journal of Experimental Marine Biology and Ecolo gy 178: 79-95 Williams GA, Morritt D. 1995. Habitat partitioning and thermal tolerance in a tropical limpet, Cellana grata. Marine Ecology-Progress Series 124:89-103. Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Physiolo gical responses to heat stress on a tropical shore: the benefits of mushrooming behaviour in the limpet Cellana grata. Marine Ecology Progress Series 292: 213-224


Project Title: Comparative proteomic responses of the intertidal limpet, Cellana grata, to heat and hypo-osmotic stress: a laboratory verification
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2008
Completion Date: 05/2010
Abstract:
The objectives of this proposal are 1. To reveal protein profiles and identify potential protein markers of intertidal limpets under heat and rain stress and 2. elucidate the possible pathways associated with these physiological responses. Research Background Located at the fringe of terrestrial and marine environments, the intertidal zone inherits extreme environmental conditions from both sources. Over a tidal cycle, organisms living on this gradient experience cool, high salinity seawater during submergence, followed by rapidly changing conditions when uncovered and exposed to hot, drying air (Little & Kitching, 1996). During emergence, individuals may also experience rainfall, resulting in these marine organisms being stressed from immersion in freshwater (Morritt et al, 2007). Such a situation is especially true in tropical intertidal environments, which are extremely stressful due to high temperatures (air temperatures > 35 ºC) and monsoonal rains in the summer months (Garrity, 1984). More impo rtantly, the extent and frequency of these extreme environmental conditions is expected to be exacerbated based on climate change projections of elevated temperature (+3.3 ºC by 2100 in East Asia) and precipitation (+9% by 2100 in East Asia, IPCC 2007). Hong Kong shores experience such a monsoonal climate, and therefore have a physically harsh environment, varying between cool, dry almost temperate winters and hot and wet tropical summers (Kaehler & Williams 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams 1994; Williams et al. unpublished data, where > 50% of all individuals on a shore can be killed). This mass mortality is known to be associated with heat and desiccation stress during hot, summer low tides (Garrity 1984, Williams et al. 2005). Interspersed among these hot desiccating conditions (when animals experience hyper-osmotic stress due to dehydration), the intertidal biota are also stressed by intensive monsoonal rains which can exceed 500mm per day or >100mm per hour (Hong Kong Observatory ) and which result in hypo-osmotic stress (Morritt et al. 2007). This regular phenomenon illustrates that environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of many intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. To survive these environmental stresses, organisms can perform a number of behavioural or physiological strategies. If they are mobile, th ey can avoid excess heat by hiding from the sun, living in refuge habitats which are damp and cool (Williams & Morritt, 1995) and timing their activity patterns to avoid stressful periods (Ng & Williams, 2006). Non-mobile species, and those mobile species which cannot find safe refuges, utilize physiological responses to minimize stresses; varying heart rate (Chelazzi et al. 1999), water evaporation (Williams & Morritt, 1995; Harper & Williams, 2001) and haemolymph osmolality (Chan et al. 2006). In extreme cases animals can adop t final, last-gasp, responses – lifting their shells or opening their opercula to rapidly cool, but with the risk of mortality due to water loss (Williams et al. 2005). To cope with osmotic stress, marine invertebrates can handle moderate salinity change by cell volume regulation involving changes in intracellular amino acid and inorganic ion concentrations (Gainey 1994). In the case of prolonged / intensive hypo-saline exposure, animals often resort to “behavioural osmoregulation” whereby they isolate their soft tissue from the osmotically stressful environment, such as shutting the valves in bivalves or in snails by closing their aperture with their operculum. Such behavioural isolation, however, can often only be sustained for a short-time due to the expenses of depressed metabolism and adverse physiol ogical effects (Sokolova et al. 2000). The induction and outcome of these behavioural and physiological responses are mainly driven by a series of reactions at the cellular and subcellular level. Knowledge at this level is limited and investigations have mainly focused on meas urement of selected stress related proteins. The development of proteomics overcomes this problem, providing a high-throughput analyzing system for rapid measurement and identification of known or unknown protein mixtures (Nunn & Timperman 2007). This allows investigators to determine how organisms are able to biochemically cope and respond to varying environmental stresses through the analysis of the expressed proteome in particular environmental conditions. This study is, therefore, designed to investigate, using a well-studied and common intertid al limpet, Cellana grata, as a model organism, the physiological responses and proteome expression under laboratory controlled heat and rain stresses. The study will specifically identify the protein markers and pathways associated with the stress response. We plan future extension of this baseline information to other members of the intertidal community, allowing us to examine interspecific variation with respect to species’ distributions and ecologies. References: Chan BKK, Morritt D, De Pirro M, Leung KMY, Williams GA. 2006. Marine Ecology Progress Series 328: 195-204 Chelazzi G, Williams GA, Gray DR. 1999. Journal of Marine Biological Association of U.K. 79: 749-751. Gainey LF. 1994. Journal of Experimental Marine Biology and Ecology 181:201-21 Garrity SD. 1984: Ecology 65: 559–574. Harper KD, Williams GA. 2001. Journal of Zoology 253:293-300 Hong Kong Observatory Monthly meteorological normals and extremes for Hong Kong. http://www.hko.gov.hk/wxinfo/climat/normals.ht m. IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marqui s, K.B. Avery, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. Kaehler S, Williams GA. 1996. Marine Biology 125: 177-187 Little, C, Kitching, J. 1996. The Biology of Rocky Shores. New York: Oxford University Press Morritt D, Leung KMY, De Pirro Maurizio, Yau C, Wai TC, Williams GA (2007) Journal of Experime ntal Marine Biology and Ecology 352: 78-88 Ng JSS, Williams GA. 2006. Marine Ecology Progress Series 321: 183-192 Nunn BL, Timperman AT. 2007. Marine Ecology Progress Series 332: 281-289 Sanders BM, Hope C, Pascoe VM, Martin LS. 1991. Physiological Zoology 64: 1471-1489 Sokolova, I.M., Bock, C., Pörtner, H.-O., 2000. Journal of Comparative Physiology B 170: 91–103 Williams GA. 1994. Journal of Experimental Marine Biology and Ecology 178: 79-95 Williams GA, Morritt D. 1995. Marine Ecology-Progress Series 124:89-103. Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Marine Ecology Progress Series 292: 213-224


Project Title: Effect of metabolic rate regulation on heat shock response of the high shore snail Echinolit torina malaccana
Investigator(s): Williams GA, Ng WC
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 12/2009
Abstract:
The objectives of this proposal are 1. To investigate the physiological response (heart rate) of Echinolittorina malaccana to thermal stress under different metabolic states (active, short and long aestivation periods) 2. To investigate the expression profile of HSP70 during thermal stress and recovery phases. 3. To link HSP70 expression to physiological response shown to thermal stress at the different metabolic states Research Background Located at the fringe of terrestrial and marine environments, the intertidal zone inherits extreme environmental conditions from both sources. Over a tidal cycle, organisms living on this gradient experience cool, high salinity seawater during submergence, followed by rapidly changing conditions when uncovered and exposed to hot, drying air (Little et al., 2009). Hong Kong shores experience such a monsoonal climate, and therefore have a physically harsh environment, varying between cool, dry almost temperate winters and hot and wet tropical summers (Kaehler & Williams, 1996). During calm, low waters in the transition between summer and winter, mass mortalities of organisms can occur (Williams 1994; Firth and Williams, 2009; Willi ams et al. unpublished data, where > 50% of all individuals on a shore can be killed). This mass mortality is known to be associated with heat and desiccation stress during hot, summer low tides (Williams et al. 2005). This regular phenomenon illustrates that environmental conditions on Hong Kong rocky shores are at, or beyond, the survival limits of many intertidal organisms, and hence make it an excellent place to investigate the strategies utilized by species to survive these conditions. Species living at the upper intertidal zone, encounter a more prolonged emersion period which can extend to days or weeks without supply of sea water, depending on the tidal regime. These animals may undergo metabolic rate depression in order to reduce energy consumption, as well as to avoid excessive thermal and hypoxic stress (Storey & Storey 1990). Upon the metabolic rate depression or aestivation, animals undergo a series of internal physiological processes to reduce energy-producing and energy consuming reactions and marine molluscs are known to be able to depress metabolic rates by 70 to 98%. The snail Echinolittorina malaccana is a common intertidal grazer at the upper littoral zone of Western Pacific rocky shores. This species has a wide geographic distribution along the Indo-West Pacific from temperate to tropical regions in both hemispheres (~30°N to 25ºS), and longitudinally from the east Australian coast in the east to the Indian coast on the west (Reid 2006). As such this species is an ideal model organism to investigate potential variation in physiological responses in a single species over a wide range of environmental conditions, with a view to understanding if tolerances of the same specie s may vary over latitudinal gradients in association with climatic conditions. This species is dominant on Hong Kong shores where it is an important grazer of the epilithic biofilm (Mak & Williams, 1999). It is the highest vertically distributed marine gastropod on Hong Kong shores and can survive for weeks without immersion (Uglow & Williams, 2001), as such it should experience the most harsh environmental conditions of all intertidal species. Metabolic rate depression in littorinids is known to be an important physiologica l response, with evidence of suppression of heart rate and oxygen consumption (Marshall unpublished data). In Echinolittorina malaccana, depression in metabolic rate is triggered by prolonged emersion and metabolic rate can be reduced to 20% when snails adopt a state of aestivation as compared with their normal active state. The differential physiological response to thermal stress in the normal and aestivation state, however, has never been reported in this and other taxa with a similar capacity of metabolic regulation. Of the potential physiological responses, the production of specific stress compensating proteins is a widely adopted strategy. Heat shock proteins (HSPs) are a class of functionally related proteins whose expression is increased when cells are exposed to elevated temperatures or other stress (Abe & Latchm an 1999). Among the HSPs, HSP70 is an important protein which takes part in the cell's machinery for protein folding, and helps to protect cells from stress. Its expression with respect to thermal stress has been well characterized in local intertidal animals (Lai 2005), and is considered suitable to quantify the level of stress response in gastropods (Dong et al 2008) This study is, therefore, designed to investigate, using Echinolittorina malaccana as a model organism, the potential responses to laboratory controlled heat stress under different metabolic states (active, short-term and long-term aestivation). Considering the wide geographic distribution of the species, the findings of this study will form the base for future extension to conspecifi cs located along similar latitudinal distribution, allowing us to evaluate the intraspecific plasticity of the stress response and the potential differential effect of temperature change on species biogeography. References: Abe H, Latchman DS. 1999. Stress proteins. Springer, New York. Dong YW, Miller LP, Sanders JG, Somero GN 2008. Heat-shock protein 70 (Hsp70) expression in four limpets of the genus Lottia: Interspecific variation in constitutive and inducible synthesis correlates with in situ exposure to heat stress. Biological Bulletin 215:173-181 Firth LB, Williams GA. 2009. The influence of multiple environmental stressors on the limpet Cellana toreuma during the summer monsoon season in Hong Kong. Journal of Experim ental Marine Biology and Ecology (in press) Chelazzi G, Williams GA, Gray DR. 1999. Field and laboratory measurement of heart rate in a tropical limpet, Cellana grata. Journal of Marine Biological Association of U.K. 79: 749-751. Kaehler S, Williams GA. 1996. Distribution of algae on tropical rocky shores: spatial and temporal patterns of non-coralline encrusting algae in Hong Kong. Marine Biology 125: 177-187 Lai CH. 2005. Heat shock protein expression in limpets on Hong Kong rocky shores. M.Phil thesis. The University of Hong Kong. Hong Kong. Little, C, Williams GA, Trowbridge C 2009 The Biology of Rocky Shores. 2nd Edition: Oxford University Press Mak, YM, Williams GA 1999 Littorinids control high intertidal biofilm abundance on tropical, Hong Kong rocky shores. Journal of Experimental Marine Biol ogy and Ecology 233:81-94 Reid DG, Lal K, Mackenzie-Dodds J, Kaligis F, Littlewood DTJ, Williams ST 2006 Comparative phylogeography and species boundaries in Echinolittorina snails in the central Indo-West Pacific. Journal of Biogeography 33:990–1006 Storey KB, Storey JM. 1990. Metabolic rate depression and biochemical adaptation in anaerobiosis, hibernation and estivation. The Quarterly Review of Biology 65:145-174 Uglow RF, Williams GA. 2001. The effects of emersion on ammonia efflux of three Hong Kong Nodilittorina species. Journal of Shellfish Research 20:489–493 Williams GA. 1994. The relationship between shade and molluscan grazing in structuring communities on a moderately-exposed tropical rocky shore. Journal of Experimental Marine Biology and Ecology 178: 79-95 Williams GA, De Pirro M, Leung KMY, Morritt D. 2005. Physiological responses to heat stress on a tropical shore: the benefits of mushrooming behaviour in the limpet Cellana grata. Marine Ecology Progress Series 292: 213-224


List of Research Outputs

Firth L.B. and Williams G.A. , The influence of multiple environmental stressors on the limpet Cellana toreuma during the summer monsoon season in Hong Kong, Journal of Experimental Marine Biology and Ecology . 2009, 375: 70-75.
Ng W.C. , Leung T.Y. and Williams G.A. , Comparative proteomic responses in two intertidal limpets (Cellana grata and Cellana toreuma) to summer low tides on tropical rocky shores, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Ng W.C. , Leung F.C.C. , Chak S.T.C. , Slingsby G. and Williams G.A. , Temporal genetic variation in populations of the limp et Cellana grata from Hong Kong shores, Marine Biology . 2010, 157: 325-337.
Poon D., Chan K.K. and Williams G.A. , Spatial and temporal variation in the diets of the crabs Metopograpsus frontalis (Grapsidae) and Perisesarma bidens (Sesarmidae): implications for mangrove food webs., Hydrobiologia . 2010, 638: 29-40.
Wai T.C. , Sin Y.T. , Cornish A., Leung K.M.Y. , Dudgeon D. and Williams G.A. , Food source utilization of the bamboo shark, Chiloscyllium plagiosum, in Hong Kong: the significance of trophic subsidies to top predators?, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Wai T.C. , Ng S.S. , Leung K.M.Y. , Dudgeon D. and Williams G.A. , The source and fate of organic matter and the significance of detrital pathways in a tropical coastal ecosystem: diet shifting of benthic invertebrates during the wet season , 3rd International Symposium of Integrative Zoology. July 7 -10, 2009. Beijing, China . 2009.
Wai T.C. , Chak S.T.C. , Ng W.C. , Leung K.M.Y. and Williams G.A. , Where and when to fish sea urchins? Spatial and temporal variation in sea urchin population structure, gonad yield and food source utilization within and outside Marine Protected Areas, 3rd International Symposium of Integrative Zoology. July 7-10, 2009. Beijing, China . 2009.
Williams G.A. , Guest Professor, Xiamen University, China . 2009.


Researcher : Wong AOL

Project Title: Novel actions of somatostatin in grass carp pituitary cells: inhibition of growth hormone synthesis through up-regulation of CREB Gene expression
Investigator(s): Wong AOL
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2006
Completion Date: 12/2009
Abstract:
To demonstrate the presence of somatostatin (SRIF) immunoreactivity in the grass carp pituitary; to confirm that SRIF can inhibit GH production and GH gene expression in grass carp pituitary cells; to test if SRIF can interact with other GH-releasing factors to regulate GH gene expression at the pituitary level; to study the role of GH transcript stability and gene transcription in SRIF inhibition of GH mRNA expression; to test if SRIF can modulate CREB production and CREB gene express ion in grass carp pituitary cells; to examine the role of transcript stability and gene transcription in SRIF-induced CREB mRNA expression; to check for spatial and temporal correlations between CREB and GH mRNA expression after SRIF treatment; to elucidate the post-receptor signa ling events mediating SRIF actions on CREB and GH mRNA expression; to test if SRIF treatment and CREB over-expression can affect the promoter activity of grass carp GH gene; to map the location(s) of SRIF and CREB responsive sequence(s) in grass carp GH promoter by 5' deletion; to identify the cis-acting element(s) in GH promoter for SRIF and CREB regulation of GH gene transcription.


Project Title: CREB co-ordinates the differential actions of c-Fos and Jun-B in PACAP-induced growth hormone gene expression in grass carp.
Investigator(s): Wong AOL
Department: Zoology
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2007
Abstract:
To establish the spatial and temporal correlation of c-Fos and Jun-B expression with PACAP-induced CREB phosphorylation & GH gene expression in carp somatotrophs; to elucidate the functional role of cAMP/PKA, PLC/PKC, Ca2+/CaM cascades in PACAP-stimulated c-Fos and Jun-B gene expression in carp somatotrophs; to characterize the genomic organization and 5’promoters of grass carp c-Fos and Jun-B genes by molecular cloning and sequence matching; to confirm that c-Fos and Jun-B promoters can be activated by PACAP through appropriate signaling mechanisms and CREB phosphorylation; to test the functi onal role of CRE sites in c-Fos and Jun-B promoters in PACAP-induced c-Fos & Jun-B gene transcription via CREB activation.


Project Title: Pituitary D1/D1A Receptor in Dop amine-Stimulated Growth Hormone Gene Expression in Grass Carp.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To establish the structural identity of grass carp D1/D1A receptor by molecular cloning and confirm its expression in carp somatotrophs isolated by laser capture microdissection; (2) To characterize the rece ptor binding specificity and functional properties of grass carp D1/D1A receptor by expression studies in mammalian cell line; (3) To examine the local actions of GH and LH on both basal as well as DA D1-stimulated D1/D1A gene expression in carp somatotrophs; (4) To elucidate the functional coupling of the cAMP/PKA pathway with MAPK- and PI3K-dependent cascades in DA D1-stimulated GH gene expression in grass carp pituitary cells; (5) To unveil the functional role of cAMP/PKA-, ERK1/2-, P38 MAPK-, and PI3K-dependent cascades and CREB phosphorylation in DA induction of GH promoter activity through D1/D1A receptors.


Project Title: Negative Modulation of Intrapituitary Feedback Loop in Grass Carp by Insulin-like Growth Factors through down-regulation of pituitary growth hormone receptor expression.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2010
Abstract:
1) To establish the structural identity of IGF-I & -II expressed in the carp pituitary and characterize their expression patterns in different pituitary cell types; 2) To examine the local actions of LH and GH on IGF-I & -II expression in grass carp pituitary cells, both at the transcript level and protein level; 3) To confirm the functional involvement of locally produced IGFs in LH- and GH-induced GHR down-regulation in ca rp pituitary cells; 4) To elucidate the functional role of ERK1/2-, P38 MAPK-, JNK- and PI3K-dependent cascades in IGF-I & -II modulation of GHR mRNA & protein expression in carp somatotrophs.


Project Title: The 92th Annual Meeting & Expo of the Endocrine Society (ENDO 2010) Functional Interactions of Activin with PACAP and GnRH in regulating Grass Carp LH beta Gene Transcription.
Investigator(s): Wong AOL
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Huo L. and Wong A.O.L. , structure and transcriptional regulation of grass carp calmodulin gene. , Biochem Biophys Res Commun . 2009, 390: 827-833.
Wong A.O.L. , Award for Teaching Excellence (2009, HK$20,000), Faculty of Sciences, University of Hong Kong . 2009.
Wong A.O.L. , GRF Merit Award (2008, HK$50,000), University Research Committee, Univeristy of Hong Kong . 2009.
Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeti ng of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Wong AST

Project Title: Outstanding Young Researcher Award 2006-2007
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Outstanding Young Researcher Award
Start Date: 11/2007
Abstract:
Nil


Project Title: The molecular basis of anoikis resistance in ovarian cancer cells.
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 10/2008
Completion Date: 09/2009
Abstract:
Ovarian cancer is a highly metastatic cancer charac terized by widespread peritoneal dissemination and ascites formation, which constitute the major cause of death in ovarian cancer patients. Current therapeutic approaches for advanced-stage or metastatic ovarian cancer have little effect and the five-year survival rates of this group of patients are only 16-28% (1). Thus, there is a need for new therapeutic targets and a better understanding of the molecular mechanisms underlying the progression of ovarian cancer. In addition to gaining functions of invasion, cell resistance to anoikis plays an important role in tumor progression and metastasis as tumor cells lose matrix attachment during metastasis (2). Anoikis, also known as suspension-induced apoptos is, is a term used to describe programmed cell death (apoptosis) of epithelial cells induced by loss of matrix attachment (2). This process is particularly relevant to ovarian cancer as unlike many tumors, ovarian cancer metastasi ze by peritoneal dissemination where tumor cells lack appropriate cell matrix contacts while in ascitic fluid during metastasis. Thus, new findings involved in the regulation of anoikis in human tumor cells may provide new insight into mechanism of tumor metastasis. However, although significant progress has been made in understan ding apoptotic signaling, little is known regarding regulation of anoikis by growth factors. Moreover, many studies on anoikis are performed in primary or immortalized rodent cells, which may be irrelevant to human cancers. We and others have demonstrated that the expression of hepatocyte growth factor (HGF) and its receptor Met play an important role in ovarian tumor progress ion and metastasis. Met is found to be overexpressed in ovarian cancer and its expression is inversely correlated with patients' survival (3-5). HGF is significantly increased in ovarian cancer ascites and cystic fluids (6, 7). HGF strongly induces proliferation, migration, and invasion of ovarian cancer cells (6, 8-10). Moreover, blocking the HGF effects using monoclonal antibodies or antagonistic framents, or inhibiting Met by siRNA abrogates ovarian cancer cell migration in vitro and delays intraperitoneal tumor growth and dissemination in vivo (5, 11, 12). Upon HGF stimulation, Met activates multiple downstream signals through its multifunctional docking site located at its carboxyl-terminal tail. A wide range of signal transducers involved in cell motility induced by HGF have been identified in several cell lines. However, the contribution of signaling pathway triggered by Met appears to be highly dependent on the cellular context. Because HGF-Met signaling is clinically associated with metastasis of ovarian cancer cells, we performed experiments to determine whether HGF provides protection against apoptosis induced by a loss of matrix attachment, and the molecular mech anisms underlying this process. References: 1. Tingulstad S, Skjeldestad FE, Halvorsen TB, Hagen B. Survival and prognostic factors in patients with ovarian cancer. Obstet Gynecol 2003;101:885-891. 2. Frisch SM, Screaton RA. Anoikis mechanisms. Curr Opin Cell Biol 2001;13:555 -562. 3. Di Renzo MF, Olivero M, Katsaros D, Crepaldi T, Gaglia P, Zola P, Sismondi P, Comoglio PM. Overexpression of the Met/HGF receptor in ovarian cancer. Int J Cancer 1994;58:658-662. 4. Huntsman D, Resau JH, Klineberg E, Auersperg N. Comparison of c-met expression in ovaria n epithelial tumors and normal epithelia of the female reproductive tract by quantitative laser scan microscopy. Am J Pathol 1999;155:343-348. 5. Sawada K, Radjabi AR, Shinomiya N, Kistner E, Kenny H, Becker AR, Turkyilmaz MA, Salgia R, Yamada SD, Vande Woude GF, Tretiakova MS, Lengyel E. c-Met overexpression is a prognostic factor in ovarian cancer and an effective target for inhibition of peritoneal dissemination and invasion. Cancer Res 2007;67:1670-1679. 6. Corps AN, Sowter HM, Smith SK. Hepatocyte growth factor stimulates motility, chemotaxis and mitogenesis in ovarian carcinoma cells expressing high levels of c-met. Int J Cancer 1997;73:151-155. 7. Baykal C, Demirtaş E, Al A, Ayhan A, Yüce K, Tulunay G, Köse MF, Ayhan A. Comparison of hepatocyte growth factor levels of epithelial ovarian cancer cyst fluids with benign ovarian cysts. Int J Gynecol Cancer 2004;14:152-156. 8. Wong AS, Roskelley CD, Pelech S, Miller D, Leung PC, Auersperg N. Progressive changes in Met-dependent signaling in a human ovarian surface epithelial model of malignant transformation. Exp Cell Res 2004;299:248-256. 9. Zhou HY, Wong AS. Activation of p70S6K induces expression of matrix metalloproteinase 9 associated with hepatocyte growth factor-mediated invasion in human ovarian cancer cells. Endocrinology 2006;147:2557-2566. 10. Zhou HY, Pon YL, Wong AS. Synergistic effects of epidermal growth factor and hepatocyte growth factor on human ovarian cancer cell invasion and migration: role of extracellular signal-regulated kinase 1/2 and p38 mitogen-act ivated protein kinase. Endocrinology 2007;148:5195-5208. 11. Sowter HM, Corps AN, Smith SK. Hepatocyte growth factor (HGF) in ovarian epithelial tumour fluids stimulates the migration of ovarian carcinoma cells. Int J Cancer 1999;83:476-480. 12. Saga Y, Mizukami H, Suzuki M, Urabe M, Kume A, Nakamura T, Sato I, Ozawa K. Expressi on of HGF/NK4 in ovarian cancer cells suppresses intraperitoneal dissemination and extends host survival. Gene Ther 2001;8:1450-1455.


Project Title: Role of GnRH in ovarian cancer metastasis
Investigator(s): Wong AST, Cheung ANY, Lin MC
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To determine if the presence of P-cadherin is necessary to facilitate peritoneal adhesion, and elucidate the signaling mechanism of P-cadherin that promotes GnRH-mediated cell invasion and motility; (2) To determine whether GnRH mediates adhesion and invasion of ovarian cancer cells to the peritoneal ECM through an integrin-mediated mechanism.


Project Title: Cross-talk between estrogen-related receptor alpha and beta-catenin signaling in ovarian cancer
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2010
Abstract:
Key issues and problems being addressed: Ovarian cancer is, after breast cancer, the second most common gynecological cancer, but has the highest mortality of all the gynecological cancers in Hong Kong and China (Hong Kong Cancer Registry). It is also the leading cause of death from gynecolgoical neoplasms in North America and Europe (1). Worldwide, it is estimated that there are ~200,000 new cases per year (equivalent to 1 new case every 2 minutes). Current therapies have little effect, with poor 5-year survival rates of only 16-28%. Despite its clinical significance, the mechanisms underlying the development and progression of ovarian cancer are among the least understood of all major human malignancies. Therefore, there is a need for new therapeutic targets and a better understanding of the molecular basis of the pathogenesis of ovarian cancer. b-catenin has a dual role in cell-cell adhesion and signaling. b-catenin is mainly localized at the plasma membrane of adherens junctions where it binds E-cadherin, which plays an important role in maintaining normal tissue architecture and contact inhibition. In contrast, free b-catenin in the cytoplasm is a key regulator of cell proliferation, survival, and cell cycle control (3). Free, cytoplasmic b-catenin is a critical point in Wnt/b-catenin signaling. It is because free b-catenin in the cytoplasm can translocate to the nucleus where it binds to transcription factors, including TCF/LEF, and stimulate transcription of the target genes that direct cell fate (4). Therefore, in normal cells, the protein levels of free b-catenin are tightly regulated. During tumorigenesis, there is a high frequency of mutations in key genes constituting the pathways, such as APC, Axin, and b-catenin itself. Deregulation of b-catenin signaling has been detected in a number of malignancies, such as colon cancer, melanoma, hepatocellular carcinoma, ovarian cancer, breast cancer, and prostate cancer (4). Therefore, understanding its regulatory mechanisms in cancer is very intriguing and worth further investigation. This knowledge is important for understanding the cancer disease process and may be significant for cancer treatment and prevention. The recent discovery of members of the nuclear receptor family, such as androgen receptor (AR), retinoic acid receptor (RAR), retinoid X receptor (RXR), glucocorticoid receptor (GR), thyroid receptor (TR), vitamin D receptor (VDR), estrogen receptor (ER ), and peroxisome proliferator-activated receptor (PPAR) (5), can interact with b-catenin and modulate its signaling brings new hope to cancer patients. It is because the interaction between nuclear receptors and b-catenin does not depend on the Wnts. Therefore, even in the presence of various mutations in the Wnt pathway, such cross-talk can also occur to regulate b-catenin turno ver, suggesting a new direction in cancer therapy. There are many mechanisms that nuclear receptors can regulate Wnt/b-catenin signaling. For example, the cross-talk between AR, RAR, VDR and b-catenin was found to inhibit b-catenin transcriptional activation and thereby tumor formation (5). PPAR has been shown to increase the expression of PTEN to regulate b-catenin degradation via GSK3b. These processes can be regulated by the small molecule ligands. Therefore, understanding the cross-talk regulation between nuclear receptor and Wnt/b-catenin can help compound screening for new cancer drug discovery. Estrogen-related receptor alpha (ERRa), a unique member of the orpha nuclear receptor superfamily, was recently implicated in ovarian tumorigenesis, with its expression being the highest in malignant tumors (6). ERRa plays a pivotal role in the regulat ion of cell proliferation and apoptosis and is therefore an important molecular target in ovarian cancer. Moreover, although more than two thirds of ovarian cancers express estrogen receptor (ER), only a minor proportion of patients (7-18%) respond clinically to anti-estrogen treatment. It has been suggested that ERRa may be part of the explanation for the common resistance of ovarian cancer to ER blockade. Purpose of the proposed project: Recently, we show that b-catenin is a key regulator of the cellular apoptosis in human OSE and ovarian cancer cells. (7). In our preliminary study, we show for the first time that the expression of b-catenin can be regulated by ERRa. Using an in vitro transfection approach, we showed that overexpression of ERRa stro ngly inhibited b-catenin expression, indicating that ERRa can negatively regulate b-catenin activity. Furthermore, the expression pattern of ERRa in ovarian cancer appears to be opposite to b-catenin expression (8). These findings are very interesting and led us to hypothesize that ERRa may serve as a novel negative regulator of b-catenin signaling, and that ERRa inhibition of b-catenin signaling may promote the development and progression of ovarian cancer cells by stimulating cell proliferation and/or preventing apoptosis. Unraveling the molecular mechan isms underlying the cross-talk between ERRa and b-catenin signaling will help us to understand the pathogenesis of ovarian cancer and to develop novel therapeutics for ovarian cancer. In this proposal, we aim to characterize the ERRa/b-catenin cross-talk and its implication in ovarian cancer prevention and treatment. Research objectives: 1) To investigate the correlation between ERRa and b-catenin expression and distributi on in the development and progression of ovarian cancer. 2) To determine the mechanisms by which ERRa regulates b-catenin expression and signaling. References 1. Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer Statistics, 2009. CA Cancer J Clin 2009;59:225-49. 2. Auersperg N, Wong AS, Choi KC, Kang SK, Leung PC. Ovar ian surface epithelium: biology, endocrinology, and pathology. Endocr Rev 2001;22:255-88. 3. Bienz M. beta-Catenin: a pivot between cell adhesion and Wnt signalling. Curr Biol 2005;15:R64-7.. 4. Peifer, P, Polakis P. Wnt signaling in oncogenesis and embryogenesis - a look outside the nucleus. Science 287;1606-9. 5. Mulholland DJ, Dedhar S, Coetzee GA, Nelson CC. Interaction of nuclear receptors with the Wnt/beta-catenin/Tcf signaling axis: Wnt you like to know? Endocr Rev 2005;26: 898-915. 6. Stein RA, McDonnell DP. Estrogen-related receptor alpha as a therapeutic target in cancer. Endocr Relat Cancer 2006;13:S25-32. 7. Pon YL, Wong AS. Gonadotropin-induced apoptosis in human ovarian surface epithelial cells is associated with cyclooxygenase-2 up-regulation via the beta-catenin/T-cell factor signaling pathway. Mol Endocrinol 2006;20:3336-50. 8. Cheung LW, Ip CK, Wong AS. Cadherins and signaling in ovarian cancer progression . In: Cancer Metastasis - Biology & Treatment, Springer Life Sciences (in press).


Project Title: Involvement of orphan nuclear receptor Nurr77 in regulating β-catenin turnover and signaling
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: NSFC/RGC Joint Research Scheme
Start Date: 01/2010
Abstract:
To investigate the correlation between Nur77 and b-catenin expression and distribution in colon cancer specimens, and its potential significance in the development and progression of colon cancer; to investigate the mechanisms by which Nur77 regulates b-catenin expression and signaling using bile acids deoxycholic acid (DCA), ursodeoxycholic acid acid (UCDA) derivatives that have been demonstrated by our previous studies to be able to enhance or reduce the cross-talk between Nur77 and b-catenin; to screen a chemical library of natural products for novel leads that target at the Nur77/b-catenin pathway for development of new chemotherapeutic agents.


Project Title: AACR 101st Annual Meeting 2010 GnRH promotes peritoneal adhesion and dissemination of ovarian cancer cells
Investigator(s): Wong AST
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 04/2010
Completion Date: 04/2010
Abstract:
N/A


List of Research Outputs

Cheung W.T. , Leung P.C. and Wong A.S.T. , Cadherin switching and activation of p120 catenin signal ing are mediators of gonadotropin-releasing hormone to promote tumor cell migration and invasion in ovarian cancer, Oncogene . 2010, 29: 2427-2440.
Cheung W.T. , Leung P.C. and Wong A.S.T. , GnRH promotes peritoneal adhesion and dissemination of ovarian cancer cells, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5190) . 2010.
Ching W.K. , Li L. , Tsing N.K. , Tai C.W. , Ng T.W. , Wong A.S.T. and Cheng K., A Weighted Local Least Squares Imputation Method for Missing Value Estimation in Microarray Gene Expression Data, Journal of Data Mining and Bioinformatics . 2010, 4: 331-347.
Ip K.M. and Wong A.S.T. , p70 S6 kinase regulates the actin cytoskeleton in ovarian cancer cell motility by binding and cross-linking actin filaments, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5116) . 2010.
Lau M.T., Wong A.S.T. and Leung P.C., Gonadotropins induce tumor cell migration and invasion by increasing cyclooxygenases expression and prostaglandi n E2 production in human ovarian cancer cells, Endocrinology . 2010, 151: 2985-2993.
Leung K.W. and Wong A.S.T. , Pharmacology of ginsenosides: A literature review, Chinese Medicine . 2010, 5: 20.
Leung W.K., Ching A.K., Chan A.W., Poon T.C., To K.F., Wong A.S.T. and Wong N., A novel role of cdc-family gene PFTK1 in the control of liver cancer cell motility, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 5297) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptosis resistance of non-adherent ovarian cancer cells thro ugh a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2, 101th Annual Meeting of the American Association for Cancer Research, Washington, DC, (Abstract No. 1722) . 2010.
Tang K.S. , Zhou H. , Yam J.W.P. and Wong A.S.T. , c-Met overexpression contributes to the acquired apoptotic resistance of ovarian cancer cells through a cross-talk mediated by phosphatidylinositol 3-kinase and extracellular-sig nal regulated kinase 1/2, Neoplasia . 2010, 12: 128-138.
Ting C.M., Lee Y.M., Wong C.K., Wong A.S.T. , Lung H.L. , Lung M.L. , Lo K.W., Wong R.N. and Mak N.K., 2-Methoxyestradiol induces endoreduplication through the induction of mitochondrial oxidative stress and the activation of MAPK signaling pathways, Biochem Pharmacol . 2009, 79: 825-841.
Tse Y.T. , Ko F.C.F. , Tung K.K. , Chan L.K. , Lee K.W. , Wong A.S.T. , Ng I.O.L. and Yam J.W.P. , Caveolin-1 promotes hepatocellular carcinoma tumourigenesis, migration and invasion via Met-ERK1/2 pathway, Days of Molecular Medicine 2010 Systems Biology Approaches to Cancer and Metabolic Disease, Stockholm, Sweden . 2010.
Wong A.S.T. , An experimental model of ovarian carcinoma - more than just genetics, Cell Cycle . 2010, 9: 228-229.
Wong A.S.T. , Cadherins in ovarian cancer – norm for an exception, Institute of Molecular and Cell Biology, A*STAR, Singapore, March . 2010.
Wong A.S.T. , Cadherins: unique profiles and significance in ovaria n cancer, University of Chicago, Chicago, IL, April . 2010.
Wong A.S.T. , Food and Nutritional Toxicology Lecture Series: Diet, nutrition, genes, and the life-course approach to cancer and disease prevention, Kuopio, Finland, August . 2009.
Wong A.S.T. , Hepatocyte growth factor, its receptor, and their potential as novel targets in ovarian cancer, National Singapore University, Singapore, March . 2010.
Wong A.S.T. , p70 S6 kinase: a moving new role in ovarian cancer, University of British Columbia, Child and Family Research Institute, Vancouver, BC, Canada, April . 2010.


Researcher : Wong CC

List of Research Outputs

Cheng K.W. , Wong C.C. , Wang M. , He Q.Y. and Chen S.F. , Identification and characterization of molecular targets of natural products by mass spectrometry, Mass Spectrometry Reviews . 2010, 29: 126-155.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptot hecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Camptothecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong LY

List of Research Outputs

Lee Y.K. , Sit W.H. , Fan S.T. , Man K. , Jor W.Y. , Wong L.Y. , Wan L.Y. , Tan-Un K.C. and Wan J.M.F. , The cell cycle effects of docosahexaenoic acid on human metastatic hepatocellular carcinoma proliferation, International Journal of Oncology . 2010, 36(4): 991-998.
Li J. , Wong L.Y. , Lam T.Y. , Shi M. and Leung F.C.C. , A Web-based Database and Phylogenetic Tools to Study Molecular Epidemiology and Evolution of Porcine Reproductiv e and Respiratory Syndrome Virus (PRRSV) , PRRS proceedings for 2009 International PRRS Symposium . 2009, 74.
Wan J.M.F. , Sit W.H. , Yang X., Jiang P. and Wong L.Y. , Polysaccharopeptides derived from Coriolus versicolor potentiate the S-phase specific cytotoxicity of Campt othecin (CPT) on human leukemia HL-60 cells, Chinese Medicine . 2010, 27(5): 16-26.
Wong L.Y. , Jor W.Y. , Lee Y.K. , Jiang P. , Sit W.H. , Man K. and Wan J.M.F. , A Proteomic Analysis of Carbon Tetrachloride-Induced Hepatotoxicity In Rat Livers, 41st Annual Symposium, Society of Toxicology of Canada . 2009, No.48.


Researcher : Wong TWL

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductive and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposi um . 2009.


Researcher : Wong WPE

List of Research Outputs

Siu E.R., Wong W.P.E. , Mruk D.D., Sze K.L. , Porto C.S. and Cheng C.Y., An Occludin-focal Adhesion Kinase Protein Complex At The Blood-testis Barrier: A Study Using The Cadmium Model, Endocrinology . 2009, 150: 3336-3344.
Wong W.P.E. , Sun I.S., Li W.M.M. , Lee W.W.M. and Cheng C.Y. , 14-3-3 regulates cell adhesion in the seminiferous epithelium. , Endocrinology . 2009, 150: 4713-4723.
Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.
Wong W.P.E. , Mruk D.D. , Lee W.W.M. and Cheng C.Y. , Regulation of blood-testis barrier dynamics by TGF-ß3 is a Cdc42-dependent protein trafficking event. , Proc. Natl. Acad. Sci. U.S.A. . 2010, 107: 11399-11404.


Researcher : Wong WY

List of Research Outputs

Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor responses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhan ce uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Wong WY

List of Research Outputs

Li J. , Wong W.Y. , Bao W.W. and Leung K.M.Y. , Population density effect on endocrine disuptor respon ses in the marine copepod Tigriopus japonicus, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the 6th international Conference on Marine Pollutio n and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Lam C.W. , Leung T.Y. and Leung K.M.Y. , Can carbon nanotubes act as a carrier vehicle to enhance uptake and toxicity of other xenobiotics in fish?, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wong W.Y. , Bao W.W. and Leung K.M.Y. , Poplulation density effect on endocrine disruptor responses in the marine copepod Tigriopus japonicus, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc oxide to five marine organisms: influences of aggregate size and ion solubility, Analytical and Bioanalytical Chemistry . Springer, 2010, 396: 609-618.
Wong W.Y. , Leung T.Y. , Djurisic A. and Leung K.M.Y. , Toxicities of nano zinc-oxide to five marine organisms: influences of aggregate size and ion solubility, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


Researcher : Wu J

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.


Researcher : Wu SS

Project Title: Polybrominated diphenyl ethers: a ubiquitous contaminant disrupting the reproductive hormones and impairing reproduction of fish?
Investigator(s): Wu SS
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 12/2008
Abstract:
(1) Study whether, and in what way, reproductive impairment would occur in fish continuously exposed to chronic, low level of PBDEs; (2)Investigate whether PBDEs may affect production of pituitary gonadotropin hormones and their receptors; (3) Examine whether PBDEs will affect the various key genes and enzymes regulating steroidogenesis and receptors of sex hormones in fish gonads.


Project Title: Centre for Marine Environmental Research and Innovative Technology
Investigator(s): Wu SS, Lee JHW, Li XY, Li WK, Leung KMY
Department: School of Biological Sciences
Source(s) of Funding: Areas of Excellence Scheme
Start Date: 11/2009
Completion Date: 10/2012
Abstract:
n/a


List of Research Outputs

Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-sea-cage fish farm wastes, In: T C Wai1, K M Y Leung1, R S S Wu1, P K S Shin2, S G Cheung2, X Y Li3, J H W Lee3 , The 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Wai T.C. , Leung K.M.Y. , Wu S.S. , Shin P.K.S., Cheung S.G., Li X.Y. and Lee J.H.W. , Stable isotope and fatty acid profile as effective tools for diagnosing environmental impact of open-se a-cage fish farm wastes, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.
Wu S.S. , Fang J.K., Zheng G.J., Lam P.K.S. and Shin P.K .S., 196 Fang JKH, RSS Wu, GJ Zheng, PKS Lam and PKS Shin, 2010. Seasonality of bioaccumulation of trace organics and lysosomal integrity in green-lipped mussel Perna viridis. , Science of the Total Environment . 2010, 408: 1458-1465.
Wu S.S. , Tong E.S.P., van de Merwe J.P. and Chiu M.Y. , Effects of 1,2 dichlorobenzene on the growth, bioenergetics and reproduction of the amphipod Melita longidactyla, Chemosphere . 2010, 80: 20-27.
Wu S.S. , Hypoxia: Nothing could be worse, 6th International Conference on Marine Pollution and Ecotoxicology . 2010.
Wu S.S. , Journal of Bioindicators, 2010.
Wu S.S. , Marine and Freshwater Research . 2010.
Wu S.S. , Marine pollution bulletin . 2010.
Wu S.S. , Lam M.H.W., Li Q.L. and Jiang B.L., Rapid magnetic-mediated solid-phase extraction and pre-concentration of selected endocrine disrupting chemicals in natural waters by poly(divinylbenzene-co-methacrylic acid) coated Fe3O4 core-shell magnetite microspheres for their liquid chromatography-tandem mass spectrometry determination, Journal of Chromatography A . 2010, 1217: 1219-1226.


Researcher : Xiao J

List of Research Outputs

Wong A.O.L. , Ko K.W. , Xiao J. and Jiang Q. , IGF-I as novel stimulator for pituitary somatolactin  and β expression via activation of ERK1/2 and P38 MAPK cascades. , In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P43-44. . 2009.
Xiao J. , Jiang Q. and Wong A.O.L. , Novel mechanisms for SOCS3 regulation in grass carp: Synergistic actions of growth hormone and glucagon at the hepatic level., In: Proceedings of the 24th Annual Scientificl Meeting of the Society for Study of Endocrinology, Metabolism and Reproduction, Hong Kong (Nov 22, 2009), P39-40. . 2009.


Researcher : Xiao S

Project Title: Characterization of the pathogen-inducible promoter of ACBP3 in Arabidopsis
Investigator(s): Xiao S, Chye ML
Department: School of Biological Sciences
Source(s) of Funding: Small Project Funding
Start Date: 09/2008
Completion Date: 02/2010
Abstract:
Previous studies have revealed that recombinant ACBP3 binds [14C]arachidonyl-CoA with high affinity in vitro, in comparison to [14C]palmitoyl-CoA and [14C]oleoyl-CoA (Leung et al., 2006). By transient expression and stable transformation of Arabidopsis expressing autofluores cence-tagged fusions, ACBP3 was shown to be extracellularly-targeted via the secretory pathway (Leung et al., 2006; Xiao, 2008). It has been proposed that such extracellular localization of ACBP3 is well-positioned for its possibl e interaction with pathogens and triggering of defenses against them (Leung et al., 2006). The regulation of genes encoding plant ACBPs has not been reported. Our recent preliminary data from northern blot analysis revealed that the ACBP3 mRNA is up-regulated by pathogen infection, pathogen elicitors and defense-related phytoh ormones. It is also modulated by light/dark cycling. Hence, it would be interesting to characterize the conserved regulatory elements on the promoter of ACBP3 to provide the molecular basis for the regulated expression of ACBP3 transcription related to plant defense response. The objectives of this study are to: 1. generate a 1.5-kb fragment containing the ACBP3 promoter and to generate its deletions derivatives using Polymeras e Chain Reaction (PCR); 2. clone the PCR fragments into pGEM-T EASY vector and confirm sequences by DNA sequence analysis; 3. fuse each ACBP3 promoter fragment to β-glucuronidase (GUS) reporter gene to generate ACBP3-GUS fusions; 4. introduce the ACBP3 promoter- and deletion derivatives-GUS fusions into wild type Arabidopsis to generate stable transgenic Arabidopsis; 5. determine the regulation of ACBP3 mRNA and the effects of its deletions on transcriptional regulation in tr ansgenic plants. In Arabidopsis thaliana, besides the 10-kDa ACBP (Engeseth et al., 1996) which is designated as ACBP6 (Xiao et al., 2008), there are five larger forms (designated ACBP1 to ACBP5) ranging in size from 37.5 to 73.1 kDa (Chye, 1998; Chye et al., 2000; Leung et al., 2004, 2006). ACBP1 (Chye, 1998; Chye et al., 1999) and ACBP2 (Li and Chye, 2003) are membrane-assoc iated proteins while ACBP3 is an extracellularly-targeted protein (Leung et al., 2006). The localization of ACBP1, as investigated by western blot analysis of Arabidopsis subcellular fractions and immuno-electron microscopy using anti-ACBP1 antibodies, as well as by confocal laser scanning microscopy of autoflurescence-tagged ACBP1 transiently expressed in onion epidermal cells, localized ACBP1 to the ER and the plasma membrane (C hye, 1998; Chye et al., 1999; Li and Chye, 2003). Western blot analysis of Arabidopsis subcellular fractions and confocal microscopy of autofluorescence-tagged ACBP2 also located ACBP2 to the ER and the plasma membrane (Chye et al., 2000; Li and Chye, 2003). Extracellular localization of ACBP3 was experimentally verified by confocal laser scanning microscopy using autofluorescence -tagged ACBP3 transiently expressed in tobacco BY-2 cells and onion epidermal cells (Leung et al., 2006). The ACBP3 cleavable signal peptide was confirmed essential in extracellular secretion because removal of this peptide obliterated targeting. Northern blot analyses revealed that the ACBP3 mRNA was up-regulated by pathogen infection, pathogen elicitors and defense-related ph ytohormones, and was modulated by light/dark cycling (Xiao, 2008). Transgenic Arabidopsis overexpressing ACBP3 displayed enhanced resistance to the bacterial pathogen Pseudomonas syringae, whereas the acbp3 T-DNA insertional mutant was more susceptible to pathogen infection. The expression of PR genes in the acbp3 mutant was greatly reduced in both local and systemic leaves upon bacterial pathogen infection (Xiao, 2008). Furthermore, the ACBP3-overexpresso rs showed accelerated leaf senescence and enhanced sensitivity under constant darkness treatment (Xiao, 2008). These findings suggest that ACBP3 is likely involved in plant defense response against bacterial pathogens and in leaf senescence in Arabidopsis. To confirm gene regulation of Arabidopsis ACBP3 by pathogen and light, characterization of the conserved regulatory element s in the promoter of ACBP3 gene will be carried out. Revelations on the molecular mechanism of pathogen- and light-regulation of ACBP3 transcription expected from this study would further our understanding on the function of ACBP3 in defense and leaf senescence in Arabidopsis. References: Chye, M.L. 1998. Plant Mol. Biol. 38, 827-838. Chye, M.L., Huang, B.Q., and Zee, S.Y. 1999. Plant J. 18, 205-214. Chye, M.L., Li, H.Y., and Yung, M.H. 2000. Plant Mol. Biol. 44, 711-721. Engeseth, N.J., Pacovsky, R.S., Newman, T., and Ohlrogge, J.B. 1996. Arch. Biochem. Biophys. 331, 55-62. Leung, K.C., Li, H.Y., Mishra, G., and Chye, M.L. 2004. Plant Mol. Biol. 55, 297-309. Leung, K.C., Li, H.Y., Xiao, S., Tse, M.H., and Chye, M.L. 2006. Planta 223, 871-881. Li, H.Y., and Chye, M.L. 2003. Plant Mol. Biol. 51, 483-492. Xiao, S. 2008. PhD thesis, the University of Hong Kong. Chapter IV, 94-132. Xiao, S., Gao, W., Chen, Q.F., Ramalingam, S., and Chye, M.L. 2008. Plant J. 54, 141-151.


Project Title: 21st International Conference on Arabidopsis Research The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development
Investigator(s): Xiao S
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 06/2010
Completion Date: 06/2010
Abstract:
N/A


List of Research Outputs

Chen Q. , Xiao S. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acbp1acbp2 double mutant lacking acyl-CoA-binding proteins ACBP1 and ACBP2 is embryo lethal, New Phytologist . 2010, 186: 843-855.
Chye M.L. , Xiao S. , Gao W. and Chen Q. , Arabidopsis acyl-CoA-binding proteins ACBP1, ACBP2 and ACBP6 are stress-responsive, 8th Cross-Strait Symposium on Plant Molecular Biology and Biotechnology, Shanghai, 27th - 31st July, 2009, Session 13, p. 51, Invited talk . 2009.
Chye M.L. , Xiao S. , Chen Q. and Gao W. , Biocatalysis and Molecular Engineering, Biocatalysis and Molecular Engineering, Chapter 6 (ISBN 9780470487594) edited by C.T. Hou. . USA, John Wiley and Sons, 2010, 83-97.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , Depletion of the membrane-associated acyl-CoA-binding protein ACBP1 confers freezing tolerance in Arabidopsis, Plant Physiology . 2010, 152: 1585-1597.
Du Z. , Xiao S. , Chen Q. and Chye M.L. , The Arabidopsis mutant lacking acyl-CoA-binding protein ACBP1 is freezing tolerant., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, 6 th - 10 th June, 2010. Poster 03004 p. 77 . 2010.
Gao W. , Li H. , Xiao S. and Chye M.L. , Acyl-CoA-binding protein 2 binds lysophospholipase 2 and lysoPC to promote tolerance to cadmium-induced oxidative stress in transgenic Arabidopsis, Plant Journal . 2010, 62: 989-1003.
Gao W. , Xiao S. and Chye M.L. , The protein interactors of Arabidopsis acyl-coenzyme A-binding protein 2 are stress-resposive, UGC-AoE Seminar Series 2009, Chinese University of Hong Kong, Hong Kong, 24th Oct, 2009, p. 11, Invited talk . 2009.
Xiao S. , Chen Q. and Chye M.L. , Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis, Plant Signaling & Behavior . 2009, 4: 1063-1065.
Xiao S. , Chen Q. and Chye M.L. , Light-regulated Arabidopsis ACBP4 and ACBP5 encode cytosolic acyl-CoA-binding proteins that bind phosphatidy lcholine and oleoyl-CoA ester, Plant Physiology and Biochemistry . 2009, 47: 926-933.
Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.
Xiao S. , Chen Q. , Qi W., Mishra G., Ma J., Wang M. and Chye M.L. , The Arabidopsis acyl-CoA-binding proteins ACBP1 and ACBP2 are essential for early embryo development., 21 st International Conference on Arabidopsis Research, Yokohama, Japan, June 6 - 10, 2010. Poster 06002 p. 126 . 2010.


Researcher : Xu RJ

Project Title: A study on the physiological role of transforming growth factor [beta] in postnatal ad aptation of the gastrointestinal tract in neonatal pigs
Investigator(s): Xu RJ
Department: Zoology
Source(s) of Funding: Small Project Funding
Start Date: 11/2003
Abstract:
To investigate the possible physiological role of TGF-[beta] in regulation of postnatal adaptation of the gastrointestinal tract in neonatal animals.


List of Research Outputs

Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prostate cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.


Researcher : Xu X

List of Research Outputs

Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Yan A

Project Title: Exploring the Regulatory Mechani sm of Escherichia coli Global Transcription Factor FNR
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 11/2008
Abstract:
Background: Molecular oxygen (O2) has a major impact on the ecosystem and life forms on earth. Bacteri a as the earliest colonizer in all life forms have developed defined regulatory systems to deal with O2 stress and facultative anaerobes are among the best known. They are able to generate ATP through both aerobic respiration when O2 is present and through fermentation when O2 is deprived. This ability of switching between aerobic and anaerobic energy generation pathway is particularly crucial for the survival and development of enterobacterial pathogens and their subsequent infection of human host, since O2 deprivation is the primary environmental stress these organisms encounter in their invasion of host gastrointestinal tract (1). In almost all of the gram negative enterobacteria, this process is primarily controlled by the global transcription factor FNR (fumarate nitrate reduction) (7). In E. coli, FNR directly senses the changes of extra-cellular O2 and alters the express ion profile of hundreds of genes (3, 4). It can both activate transcription of the genes whose products are required in anaerobic respiratory pathway and repress expression of the genes that are involved in aerobic energy generati on. The ability of FNR to function as an O2 sensor is dependent on its [4Fe-4S] cluster which is ligated to the protein through four cysteine residues at the N-terminal halve of the protein (5, 10). Under anaerobic conditions, FNR exists as a homodimer with each monomer containin g a [4Fe-4S]2+ cluster, which promotes dimerization and site-specific DNA binding and accordingly gene regulation (8). Upon a switch to aerobic conditions, the [4Fe-4S]2+ cluster is converted to a [2Fe-2S]2+ cluster by O2, resulting in the disassembly of the FNR dimer and subseque nt loss of site-specific DNA binding (5, 6). FNR is highly conserved in all enterobacteria. It belongs to the CRP/FNR superfamily of transcription factors that have a conserved helix-turn-helix motif in the C-terminal domain required for DNA binding and a diversified N-terminal domain for effector binding, such as in cAMP receptor protein (CRP), it binds cAMP. This N-terminal region confers specificity of this class of transcri ption factors in responding to extracellular signals, such as O2, CO, aromatic compounds, or oxoglutarate, etc (2, 9). While regions in E. coli FNR that are responsible for DNA binding, dimerization, as well as interaction with the RNA polymerase (RNAP) have been identified through their analogy with the corresponding regions in E. coli CRP, the function of the N-terminal region of FNR encompassed by the first 29 amino acid residu es remains unclear due to lack of a similar region in CRP. Nonetheless, this region may confer a regulatory mechanism that is unique to FNR since it is in the domain of FNR that binds Fe-S cluster and is highly conserved among FNR homologues in all enterobacteria. Objectives: This proposal aims to systematically study the functions of this unique region in FNR using the approach of alanine scanning. Owing to the fact that FNR is subject to complicated self-autoregulation (11), we will choose the pET11a as the vector in which expression of the variants will be driven by the unified T7 promoter to generate the alanine substitution library. The objectiv es of the research are: 1) Site-directed mutagenesis to generate the 3-alanine block substitution library in the N-terminal region of FNR; 2) Transformation of the mutation library to the strains that have fnr null allele and a specific promoter from an FNR activated gene being fused to lacZ (12). In vivo and in vitro assay for transcription activities of these mutants; 3) Western-blot analysis to examine the FNR protein levels in the strains that carry various of FNR mutations; 4) Further point mutation and truncation mutagenesis to dissect the roles of the amino acid residues in this region. Information from these experiments are expected to reveal the unique mechanism of FNR regulation and provide evolutionary significance for this class of transcription factor superfamily owing to the diversity of the extra-cellular signals this large class of transcription factor sensing. As a collaborator of this project, Professor Patricia J. Kiley in the Department of Biomolecular Chemistry, the University of Wisconsin – Madison, who is an expert in this area, will provide parental plasmids and strains for molecular cloning for this investigatio n as well as necessary discussion to facilitate the achievement of project objectives.


Project Title: Transcriptional regulation of multidrug resistance genes by anaerobic adaptation in Escherich ia coli
Investigator(s): Yan A, Huang J
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 07/2009
Abstract:
1) Substantiate the molecular mechanism of transcriptio nal activation of multidrug efflux transporter genes in E. coli under anaerobic conditions; 2) Examine multidrug resistance phenotype in anaerobic E. coli cells; 3) Characterize substrate capacities and mechanisms of selective drug exporters.


Project Title: The 2009 Molecular Genetics of Bacteria and Phages Meeting The N- and C- terminal regions of E. coli global transcription factor FNR participate in regulation of FNR protein levels
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: URC/CRCG - Conference Grants for Teaching Staff
Start Date: 08/2009
Completion Date: 08/2009
Abstract:
N/A


Project Title: Explore and molecular engineering of FNR family proteins that lead to altered sensitivity to oxygen
Investigator(s): Yan A, Sun H
Department: School of Biological Sciences
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 03/2010
Abstract:
Metalloproteins are ubiquitous in nature, accounting for 30% of all proteins in biological kingdoms. They provide unique structural framework for protein folding and serve as excellent electron carriers in oxido-red uction, thus are widely distributed in many cellular and physiological processes in nature, such as the life-sustaining process of respiration, nitrogen fixation, various metabolic pathways and photosynthesis, etc (2, 3). While their involvement in the redox catalyses has been well documented, participation of metal centers in transcriptional regulation signifies a renewed function of this class of ancient proteins that merely becomes evident since last decade (5, 6). The global transcription factor FNR that primarily controls the transition from aerobic to anaerobic lifestyle in most enteric bacteria is a paradigm of these regulatory metal proteins (6, 7). It senses O2 deprivation and promotes anaerobic metabolism by regulatin g the expression of hundreds of genes in an organism’s genome. In E. coli and many other enteric bacteria, the mechanism for FNR to sense and respond to O2 limitation is dependent on an [4Fe-4S]2+ cluster that is integrated into FNR through four essential cysteine residues. Under anaerobic conditions, FNR exists as a holo-form with a [4Fe-4S]2+ cluster present at its N-terminus. The binding of the [4Fe-4S]2+ cluster promotes dimer ization of FNR, and subsequently enables site-specific DNA binding and transcription regulation (8, 9). Upon switch to aerobic conditions, O2 rapidly reacts with the [4Fe-4S]2+ cluster and converts it to a [2Fe-2S]2+ cluster. The [2Fe-2S]2+ form of protein (referred as 2Fe-FNR) is unable to dimerize, thus the protein loses its capability of site-specific binding of DNA and transcription regulation (4, 12). The 2Fe-FNR is further converted by the superoxide species, presumably a by-product of aerobic metabolism, to the cluster-less apo-FNR, a form that exists in aerobically grown E. coli (13). FNR homologues broadly exist in the species of γ-proteobacteria including some human pathogens, such as Salmonella typhimurium, Yersinia pestis, Vibrio cholerae, Pseudomonas aeruginosa, etc (7). In addition to anaerobic respiration, they mediate a diversity of cellular and physiological activities in these organisms, including denitrification, anoxygenic photosynthesis, nitrogen fixation and haemolysis. All of these FNR homologues contain the conserved cysteine residues that are required for cluster binding, sugg esting a similar Fe-S cluster dependent mechanism in these proteins (7). However, the natural and symbiotic habitats of these organisms vary and the degree of O2 deprivation these organisms can survive is not the same. How the same type of O2 sensor ([4Fe-4S]2+ cluster) respond to different ranges of O2 levels is essentially unkno wn. Since the structure and oxidation state of the [4Fe-4S]2+ cluster in these FNR homologues is identical, we hypothesize that the local protein environments surrounding the cluster may determine the stability of their [4Fe-4S]2+ cluster to O2, thus specifies the range of O2 level a microorganism can live. Two other facts support this hypothesis: 1) although a vast number of biologically important proteins contain Fe-S clust ers and employ the clusters for catalysis and function, there are only four basic types of Fe-S clusters. The specific roles of the Fe-S clusters in these different metalloproteins are at least partially attributed to the local environments formed by peptide backbones of the proteins; 2) previous studies have identified an N-terminal point mutation L28H FNR that is stable to O2 and is active in transcription regulation under aerobic conditions (1), suggesting amino acid residues in this, and probably other regions may contribute to the cluster stability. In this proposal, we aim to identify amino acid residues that control the acquisition and stability of Fe-S clusters in FNR-like proteins and uncover how these elements affect the capacity of FNR homologues to sense O2, as well as how this effect contributes to specify the ecological and physiological niches these microorganisms habitat. The specific aims are: 1. Identify regions in E. coli FNR that contribute to the acquisition and stability of Fe-S clusters and screen for O2 stable variants. 2. Purify and in vitro characterization of selective va riants. 3. Incorporate the engineered constructs into E. coli genome and test the growth of engineered strains under various ranges of O2 concentrations.


Project Title: HKU Overseas Fellowship Awards 2010-11
Investigator(s): Yan A
Department: School of Biological Sciences
Source(s) of Funding: HKU Overseas Fellowship Awards
Start Date: 06/2010
Abstract:
To visit the Great Lakes Bioenergy Research Centre and Department of Bacteriology at the University of Wisconsin-Madison, USA to learn and receive training on several recently developed genome-wide approaches in the study of microbial gene expression and conduct collaborative studies on the kinetics of an FNR mutant.


List of Research Outputs

Yan A. , HKU Overseas Fellowship Award 2010, The University of Hong Kong . 2010.
Yan A. and Kiley P... .J..., Techniques to isolate O2-sensitive proteins: [4Fe-4S]-FNR as an example, In: Richard R. Burgess and Murray P. Deutscher, Guide to Protein Purification, 2nd Edition . Elsevier publisher, 2009, 463: 787-805.
Yan A. and Pan Q. , The N- and C- terminal regions of E. coli global tran scription factor FNR participate in regulation of FNR protein levels, Molecular Genetics of Bacteria and Phages Meeting 2009, August 4-9, Madison, WI, USA . 2009.


Researcher : Yan HNH

List of Research Outputs

Wong W.P.E. , Yan H.N.H. , Li W.M.M. , Lie P.P.Y. , Mruk D.D. and Cheng C.Y. , Cell junctions in the testis as targets for toxicants, In: Charlene A. McQueen, Comprehensive Toxicology . Elservier Ltd, 2010, 11: 167-188.


Researcher : Yang Y

List of Research Outputs

Yang Y. and Dudgeon D. , Dietary variation and food selection by an algivorous loach (Pseudogastromyzon myersi: Balitoridae) in Hong Kong streams., Marine and Freshwater Research . 2010, 61: 49-56.
Yang Y. and Dudgeon D. , Response of grazing impacts of an algivorous fish (Pseudogastromy zon myersi: Balitoridae) to seasonal disturbance in Hong Kong streams. , Freshwater Biology . 2010, 55: 411-423.
Yang Y. and Dudgeon D. , Spatial and seasonal variations in benthic algal assemblages in streams in monsoonal Hong Kong., Hydrobiologia . 2009, 632: 189-200.


Researcher : Yau CST

List of Research Outputs

Sin Y.W., Chu K.H. and Yau C.S.T. , Isolation and characterization of highly polymorphic microsatellites in the mitre squid, Uroteuthis (Photololig o) chinensis, Molecular Ecology Resources . Blackwell Publishing Ltd, 2009, 9: 1460-1559.
Tang W.K. , Yau C.S.T. and Ng W.C. , Identification of stomatopod larvae (Crustacea: Stomatopoda) from Hong Kong waters using DNA barcodes, Molecular Ecology Resources . Blackwell Publishing Ltd, 2010, 10: 439–448.


Researcher : Yeung SL

List of Research Outputs

Yeung S.L. , Cheng C.W., Lui K.O. , Tsang J.S.H. , Chan W.T. and Lim B.L. , Purple acid phosphatase-like sequences in prokaryotic genomes and the characterization of an atypical purple alkaline phosphatase from Burkholderia cenocepacia J2315, Gene . 2009, 440: 1-8.


Researcher : Yeung WY

List of Research Outputs

Yeung W.Y. and Leung K.M.Y. , Effects of tissue types, animal size, nutritional status and metal exposure on the RNA/DNA ratio in various tissues to the green-lipped mussel Perna viridis, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.
Yeung W.Y. and Leung K.M.Y. , Spatio-temporal variations in metal accumulation, RNA /DNA ratio, energy reserves and condition index in transplanted green-lipped mussels Perna viridis in sub-tropical Hong Kong waters, the 6th international Conference on Marine Pollution and Ecotoxicology, 31 May-3 June 2010, City University of Hong Kong, Hong Kong . 2010.


Researcher : Yip CW

List of Research Outputs

Shi M. , Lam T.Y. , Hon C.C., Murtaugh M.P., Davies P., Hui R.K.H. , Li J. , Wong T.W.L. , Jiang J. , Yip C.W. and Leung F.C.C. , A phylogeny-based evolutionary, demographic and geographic dissection of north American type porcine reproductiv e and respiratory syndrome virus (NA-PRRSV), PRRS proceedings for 2009 International PRRS Symposium . 2009.
Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origins Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Yip WK

Project Title: Functional characterization and subcellular localization of three ethylene receptors in rice
Investigator(s): Yip WK, Yau CP
Department: Botany
Source(s) of Funding: Seed Funding Programme for Basic Research
Start Date: 01/2005
Abstract:
Ethylene is an important plant hormone which regulates a range of developmental and physiological process in plants. In the past decades, exceptional progress has been made on understanding the molecular mechanism controlling the ethylene signalling pathway which was shown to require membrane-associated ethylene receptors to function. In Arabidopsis, there are altogether five ethylene receptors which negatively regulate ethylene responses. However, little is known about the involvement of receptor genes in the ethylene perception of monocotyledonous plants such as rice. Recently, we have successfully isolated five putative ethylene receptor genes from rice and showed that their expression levels were regulated developmentally, and by various external stimuli including ethylene. Here we propose to functionally characterize three rice ethylene receptor genes, OS-ERS1, OS-ERS2 and OS-ETR2 in planta. Moreover recent studies on the subcellular localization of two ethylene receptors, At-ETR1 and NtHK1 (an ethylene receptor ortholog in tobacco) revealed that they were localized to endoplasmic reticulum and plasma membrane respectively. To understand more in detail how these three rice ethylene receptors function in cellular level, we propose to investigate their corresponding subcellular localization by fusin g with fluorescent protein.


Project Title: Characterization of a cyanide detoxification gene encoding L-3-cyanoalanine synthase (CAS), and determine its roles among the cysteine synthase (CS)/CAS family in the rice genome
Investigator(s): Yip WK
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2007
Completion Date: 12/2009
Abstract:
(1) Study of OS-CAS transcription by promoter analyses; (2) heterologous expression of OS-CAS in bacteria dnd yeast to test its catalytic activity; and unravel the structure and function relationships between CS and CAS by site directed mutagenesis studies; (3) subcellular localization of OS-CAS by tagging it with the yellow fluorescent protein (YFP); (4) the roles of OS-CAS and CS on cyanide detoxification and cysteine synthesis in rice; to investigate whether quincorac or 2,4 D resistant in rice is conferred by OS-CAS.


Project Title: The study of plant hormone interactions on growth, development and physiological responses using ACC synthase gene suppression mutants in tomatoes.
Investigator(s): Yip WK
Department: Botany
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2008
Completion Date: 12/2009
Abstract:
(1) Elucidation the interactions among ethylene, abscisic acid, and IAA on stomatal aperture and transpi ration. (2) Elucidation the interactions among ethylene, abscisic acid, and IAA on seedling growth. (3) Study on the possible hormonal interactions between ethylene and ABA in seed development in tomato fruits. (4) Gene discovery on important plant processes by employing the RNA micro-array analyses.


Project Title: Molecular studies on two components OASS and SAT of rice cysteine synthase complex and cysteine regeneration during ethylene biosynthesis
Investigator(s): Yip WK
Department: School of Biological Sciences
Source(s) of Funding: General Research Fund (GRF)
Start Date: 01/2009
Abstract:
(1) To have a basic understanding of the gene expression profiles of the OASS/CAS gene family members during seedling growth in light and in dark, and also under the ethylene/auxins treatments; (2) To find out the subcellular localization of individual OASS/CAS membe rs; (3) To verify the functions of OASS/CAS, and SATs encoded by these two gene families by complementation expression in bacteria or yeast mutants; (4) To elucidate the CS complex formation of gene products encoded by these two gene families and find out whether hetero-subunits formation would be possible; (5) To determine whethe r cysteine synthesis would be possible in rice mitochondria or cysteine has to be imported from cytosol during active ethylene biosynthesis.




Researcher : Yu M

List of Research Outputs

Tse Y.M. , Yu M. and Tsang J.S.H. , Topological analysis of a haloacid permease of a Burkholderia sp. bacterium with a PhoA-LacZ reporter, BMC Microbiology . 2009, 9: 233.
Xu X. , Yu M. , Leung K.C.J. and Tsang J.S.H. , Cloning and characterization of a DNA-binding protein from a Burkholderia species bacterium, 11th International Symposium on the Genetics of Industrial Microorganisms . Melbourne, Australia, 2010, 101.


Researcher : Yu X

List of Research Outputs

Yu X. and Gu J.D. , Effect of temperature on removal of iron cyanides from solution by maize plants, Environmental Science and Pollution Research . Berlin / Heidelberg, Springer, 2010, 17: 106-114.


Researcher : Zeng F

List of Research Outputs

Yip C.W. , Hon C.C. , Shi M. , Lam T.Y. , Chow Y.C., Zeng F. and Leung F.C.C. , Phylogenetic Perspectives On The Epidemiology And Origin s Of SARS And SARS-like Coronaviruses, Infection, Genetics and Evolution . 2009, 9: 1185-1196.


Researcher : Zeng X

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vita mins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-85 . 2010.


Researcher : Zeng X

List of Research Outputs

Cheng K.W. , Zeng X. , Tang Y.S., Wu J. , Liu Z.W., Sze K.H. , Chu I.K. , Chen S.F. and Wang M. , Inhibitory Mechanism of Naringenin against Carcinogenic Acrylamide Formation and Non-enzymatic Browning in Maillard Model Reactions , Chemical Research in Toxicology . 2009, 22: 1483-1489.
Zeng X. , Cheng K.W. , Du Y. , Kong P.W. , Lo C.S.C. , Chu I.K. , Chen S.F. and Wang M. , Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips, Food Chemistry . 2010, 1212: 424-428.
Zeng X. , Kong P.W. , Cheng K.W. , Du Y. , Tang Y.S. , Chu I.K. , Lo C.S.C. , Sze K.H. , Chen F. and Wang M. , Direct Trapping of Acrylamide as a Key Mechanism for Niacin's Inhibitory Activity in Carcinogenic Acrylamide Formation, Chemical Research in Toxicology . 2010, 23: 802-807.
Zeng X. , Cheng K.W. , Jiang Y., Lin Z.X., Shi J.J., OU S.Y., Chen S.F. and Wang M. , Inhibition of acrylamide formation by vitamins in model reaction and fried potato strips, Food Chemistry . 2009, 116: 34-39.
Zeng X. , Cheung K.W. , Jiang Y., Lin Z.X., Shi J.J., Chen S.F. and Wang M. , Inhibitory activities and potential mechanisms of vi tamins against carcinogenic acrylamide formation, 239th ACS National Meeting, San Francisco, CA, Uni ted States, March 21-25, AGFD-85 . 2010.


Researcher : Zhang Y

List of Research Outputs

Zhang Y. and Dudgeon D. , Impacts of deforestation and hydrological change on river ecosystems in Southeast Asia. , In: L. Lebel, A. Snidvongs, C.-T. A. Chen & R. Daniel, Critical States: Environmental Challenges to Development in Monsoonal Southeast Asia . Petaling Jaya, Malaysia, , Strategic Information and Research Development Centre, 2009, 268-280.


Researcher : Zheng S

List of Research Outputs

Xiao S. , Gao W. , Chen Q. , Chan S.W., Zheng S. , Ma J., Wang M. , Welti R. and Chye M.L. , Overexpression of Arabidopsis acyl-CoA-binding protein ACBP3 promotes starvation-induced and age-dependent leaf senescence, Plant Cell. . 2010, 22: 1463-1482.


Researcher : Zheng Z

List of Research Outputs

Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C. G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, Unite d States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-none nal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonen al, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induce d cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zheng Z

List of Research Outputs

Li H. , Wu W.K.K., Zheng Z. , Che C.T., Yu L., Li Z.J., Wu Y.C., Yu J., Cho C.H. and Wang M. , 2,3’,4,4’,5’-Pentamethoxy-trans-stilbene, a resveratrol derivative, is a potent inducer of apoptosis in colon cancer cells via targeting microtubules, Biochemical Pharmacology . 2009, 78: 1224-1232.
Li H. , Wu W.K.K., Zheng Z. , Che C.T., Li Z.J., Xu D.D., Wong C.C.M., Ye C.G., Sung J.J.Y., Cho C.H. and Wang M. , 3,3′,4,5,5′-Pentahydroxy-trans-stilbene, a resveratrol derivative, induced apoptosis in colorectal carcinoma cells via oxidative stress, European Journal of Pharmacology . 2010, 637: 55-61.
Zheng Z. , Chen S., Wang S., Wang X.C., Cheng K.W. , Wu J. , Yang D. and Wang M. , Chemical components and tyrosinase inhibitors from the twigs of Artocarpus heterophyllus , Journal of Agricultural and Food Chemistry . 2009, 57: 6649-6655.
Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zhou L

List of Research Outputs

Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitation of Uvaria (Annonaceae), inclusive of Anomianthus, Cyathostemma , Ellipeia, Ellipeiopsis and Rauwenhoffia, Systematics and Biodiversity . 2009, 7: 249-258.
Zhou L. , Su Y.C.F. and Saunders R.M.K. , Molecular phylogenetic support for a broader delimitat ion of Uvaria (Annonaceae): evidence for the migration of an ancestrally African genus into Asia, Annonaceae Workshop, Leiden, 7-9 August . 2009.
Zhou L. , Su Y.C.F. , Chalermglin P. and Saunders R.M.K. , Molecular phylogenetics of Uvaria (Annonaceae): relationships with Balonga, Dasoclema and Australian species of Melodorum, Botanical Journal of the Linnean Society . 2010, 163: 33-43.


Researcher : Zhu F

List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthoc yanidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prostate cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/gluco se model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Zhu F

List of Research Outputs

Cai Y. , Zhu F. , Ke J.X. and Corke H. , Inhibitory effect and primary mechanism of proanthocya nidins from grape seeds against acrylamide formation in the Maillard reaction model system (Extended abstract), The 6th International Congress on Pigments in Food: Chemical, Biological and Technological Aspects (June 20-24, 2010, Budapest, Hungary) . 2010.
Luo Q., Li Z.N., Yan J., Zhu F. , Xu R.J. and Cai Y. , Lycium barbarum polysaccharides induce apoptosis in human prosta te cancer cells and inhibits prostate cancer growth in a xenograft mouse model of human prostate cancer, Journal of Medical Food . 2009, 12 (4): 695-703.
Zhu F. , Cai Y. , Sun M. , Ke J.X., Lu D.Y. and Corke H. , Comparison of major phenolic constituents and in vitro antioxidant activity of diverse kudingcha genotypes from Ilex kudingcha , Ilex cornuta , and Ligustrum robustum , Journal of Agricultural and Food Chemistry . 2009, 57(14): 6082-6089.
Zhu F. , Cai Y. , Bao J. and Corke H. , Effect of gamma-irradiation on phenolic compounds in rice grain, Food Chemistry . 2010, 120(1): 74-77.
Zhu F. , Cai Y. and Corke H. , Evaluation of Asian salted noodles in the presence of Amaranthus betacyanin pigments, Food Chemistry . 2010, 118(3): 663-669.
Zhu F. , Cai Y. and Corke H. , Evaluation of the effect of plant extracts and phenolic compounds on reduction of acrylamide in an asparagine/glucose model system by RP-HPLC-DAD, Journal of the Science of Food and Agriculture . 2009, 89 (10): 1674-1681.


Researcher : Zhu Q

List of Research Outputs

Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-nonenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-induced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zhu Q

List of Research Outputs

Zheng Z. , Chao J. , Ma J. , Zhu Q. and Wang M. , Sulfur-containing components from pineapple (Ananas comosus). , 239th ACS National Meeting, San Francisco, CA, Un ited States, March 21-25, AGFD-138, poster. . 2010.
Zheng Z. , Cheng K.W. , Zhu Q. , Wang X.C., Lin Z. and Wang M. , Tyrosinase inhibitory constituents from the roots of Morus nigra: a structure-activity relationship study, Journal of Agricultural and Food Chemistry . 2010, 58: 5368-5373.
Zhu Q. , Zheng Z. , Cheng K.W. , Wu J. , Zhang S., Tang Y.S., Sze K.H. , Chen J., Chen S.F. and Wang M. , Natural Polyphenols as Direct Trapping Agents of Lipid Peroxidation-derived Acrolein and 4-Hydroxy-trans-2-n onenal, Chemical Research in Toxicology . 2009, 22: 1721-1727.
Zhu Q. , Zheng Z. , Cheng K.W. , Chen S.F. and Wang M. , Natural polyphenols as sequestering agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-no nenal, 239th ACS National Meeting, San Francisco, CA, United States, March 21-25, AGFD-65 . 2010.
Zhu Q. , Zheng Z. , Chao J. , Chang R.C.C. and Wang M. , Protective effects of natural polyphenols in acrolein-ind uced cytotoxicity, 5th International Symposium on Healthy Aging . 2010, Page 53.


Researcher : Zurcher NA

List of Research Outputs

Leung M.C.C., Hui J.C.T., Zurcher N.A. , Yuan D.X. and Leung K.M.Y. , Trace metals and methyl mercury in sharks' fins: potential health risk for consumers, the SETAC Asia/Pacific 2010 Meeting, held during 4-7 June 2010 at Guangzhou, China . 2010.


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