DEPT OF ECOLOGY & BIODIVERSITY
| Researcher : Corlett RT |
| Project Title: | Checklist of the vascular plant flora of Hong Kong |
| Investigator(s): | Corlett RT |
| Department: | Ecology & Biodiversity |
| Source(s) of Funding: | Other Funding Scheme |
| Start Date: | 09/1992 |
| Abstract: |
| To produce an accurate checklist of the vascular plant species occurring in Hong Kong. |
| Project Title: | Conservation ranking of Hong Kong habitats |
| Investigator(s): | Corlett RT |
| Department: | Ecology & Biodiversity |
| Source(s) of Funding: | Other Funding Scheme |
| Start Date: | 01/1994 |
| Abstract: |
| To establish an objective system for ranking terrestrial habitats in Hong Kong in terms of their conservation value. |
| Researcher : Dudgeon ADM |
| 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 similarities 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 biodiversity 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 study 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 studies 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. |
| 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 similarities 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 biodiversity 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 study 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 studies 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. |
| Researcher : Gu J |
| 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 phylogenetically 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 |
| 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 phylogenetically 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 |
| 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 conditions 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 correspondence) 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 epidemic 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 biological 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 comprehensive 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 England, 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 England 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 |
| 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 : 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, Oratosquilla 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 establish 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 toxicity data; to validate these predictions through the generation/compilation of extensive ecotoxicity datasets for a number of model 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 tropical 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 Meeting 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 |
| Leung K.M.Y., A fitness cost for thermal tolerance in the marine copepod Tigriopus japonicus: implication on long-term biological effects of global warming, an invited Plenary Lecture presented at the 3rd International Symposium of Integrative Zoology which was held at the Institute of Zoology, Chinese Academy of Science, Beijing, China during 8-10 July. 2009. |
| Researcher : Lui KY |
| 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. |
| Researcher : Morton BS |
| Project Title: | The impact of ghost fishing on Hong Kong's artificial reef communities |
| Investigator(s): | Morton BS |
| Department: | Ecology & Biodiversity |
| Source(s) of Funding: | Environment and Conservation Fund |
| Start Date: | 03/2001 |
| Abstract: |
| Each day, fishing nets are lost in the shallow coastal waters of Hong Kong. This is a study of the impacts of such "ghost" nets upon the benthic fauna and fish to determine their impacts upon resident local species. |
| 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 interdisciplinary 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 elective 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, chemistry 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 will 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 feature 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 demonstrated 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 fingerprints 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 analysis 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 (environmental 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 structure (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 laboratory 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 microbial 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 abiotic 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-arid 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 dominated 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 nitrogen 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 result 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). |
| 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-Pacific |
| 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 has 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% species 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 populations 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 commercially 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 Atlantic 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 microsatellite 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. |
| 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 supraspecific 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 characteristics 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 Dasymaschalon 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 clades; 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 Friesodielsia (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 varies. 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 apertures 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 homologous 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 that 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 tepals (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 characters 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 controlled 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 Friesodielsia, 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 developing 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 development controlled by genes previously responsible for outer petal development. The proposed research aims to clarify problems of generic delimitation in the Dasymaschalon-Desmos-Friesodielsia 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 related 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 questions 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 regions), 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 phylogenetic 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-supported 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, Australia, 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 & Saunders, 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 (Morat 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 Hall, 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 |
| Kessler P.J.A. and Saunders R.M.K., Annonaceae, Flora of Thailand. 2010. |
| Saunders R.M.K., Member of editorial board, , Journal of Tropical and Subtropical Botany. 2010. |
| Researcher : Wang J |
| List of Research Outputs |
| Wang J., Chalermglin P. and Saunders R.M.K., The genus Dasymaschalon (Annonaceae) in Thailand, Systematic Botany. 2009, 34: 252-265. |
| 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 temporal 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 intertidal 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 gradient 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 anecdotal 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 evaporation (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-studied 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 Zoology 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 Ecology 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 Ecology 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. 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 |
| 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 importantly, 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, they 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 adopt 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 physiological 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 measurement 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 intertidal 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.htm. 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. Marquis, 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 Experimental 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 Echinolittorina 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; 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 (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 species 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 physiological 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 & Latchman 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 conspecifics 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 Experimental 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 Biology 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 |
| Researcher : Wong KY |
| List of Research Outputs |
| 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 : Xia X |
| Project Title: | Annual Meeting of the Society for Molecular and Evolution Mutation, GC Content, and the Length of Proteins |
| Investigator(s): | Xia X |
| Department: | Ecology & Biodiversity |
| Source(s) of Funding: | URC/CRCG - Conference Grants for Teaching Staff |
| Start Date: | 06/2000 |
| Abstract: |
| N/A |