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Biographical Sketch
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Dr. Donal T. Manahan is a professor of marine biological sciences at the University of Southern California (USC) in Los Angeles. His area of research is environmental physiology and adaptation of marine animals, specifically marine invertebrates and their developmental biology in different environments. He has been the Chief Scientist for over 20 scientific expeditions in Antarctica and in the Pacific Ocean (hydrothermal vents).
He was born in Ireland and obtained his undergraduate degree in zoology from Trinity College (University of Dublin). His Ph.D. is from the University of Wales (Bangor, UK), where he studied the physiology of marine animals. From 1980 to 1983, he was a postdoctoral fellow at the University of California, Irvine, where he worked in the field of physiology and developmental biology.
While on the faculty at USC, he has held various administrative positions, including: Director of Environmental Biology; Chair of the Department of Biological Sciences; and Dean of Research of the USC College of Letters, Arts and Sciences. Nationally, he has served as Chair of the US National Academies Polar Research Board and on the National Science Foundation Decadal Group-Planning Committee for Ocean Sciences (2000). He currently serves on an NSF Federal Advisory Committee to the Director of NSF's Office of Polar Programs.
In 2000, "Manahan Peak" in Antarctica was named in honor of his contributions to research and education on the continent. In 2001, he was appointed as a lifetime "National Associate" of the US National Academies in recognition of his service to the nation in matters of science.
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Education
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 B.S. Zoology, Trinity College, University of Dublin, Ireland, 6/1976
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Ph.D. Physiology & Marine Biology, University of Wales, U.K., 3/1980
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Postdoctoral Training
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Lecturer and Postdoctoral Research Fellow (physiology and developmental biology), University of California, Irvine, 1980-1983
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Description of Research
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Summary Statement of Research Interests
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The majority of marine animals have a larval stage of development that is intermediate between the egg and the adult stages. In spite of the obvious
importance of larvae in the life cycles of most marine animals, little is
understood about the biology of these complex life history stages when
compared to what is known about comparable adult forms.
My specific area of research is the environmental physiology of development
of marine invertebrates, especially the larval stages. Understanding
growth and development of any animal in its environment - be it terrestrial
or aquatic - is a complex process. For species of marine animals, the
problem of understanding the biology of larval stages is further
complicated by the vast scales and different environments of the world's
oceans over which life-history strategies are known to vary.
The approaches being undertaken in my laboratory to study "how larvae work"
include the following:
(1) environmental adaptations of larvae, studied using different levels of
biological analysis (e.g., ecology, physiology, biochemistry, and molecular
biology);
(2) comparative studies of species with different life-history strategies
that develop in very different oceanic environments [e.g., the cold, polar
oceans of Antarctica; warmer, temperate oceans (California); and deep-sea
environments, such as hydrothermal vents];
(3) studies of genetically-determined variability in physiological
performance ("Nature vs. Nurture"), with the application of quantitative genetics to make phenotypic contrasts to define the physiological bases of biological
variation. This research includes genomic analysis of variations in
complex physiological traits (i.e., the identification of genes that regulate complex traits such as growth, feeding, metabolism etc.). Combined, the results of such studies enhance understanding of growth and development of animal stages and dispersal potential in the ocean, with respect to population connectivity and ecological recruitment. There are also some 'applied' aspects to some of this research. These include studies of larval forms of marine species on the Federal (USA)
Endangered Species List (e.g., California White Abalone) in an effort to
optimize culturing conditions for possible restoration projects. Our
studies of cellular growth and development have revealed highly energy-efficient biochemical processes in "extreme polar environments" that involve rates of gene transcription and translation. These novel processes might have biotechnological implications. Additionally, we are searching for ways to improve the production of food from the ocean for human consumption through the application of "hybrid vigor" to enhance growth
rates of marine animals through aquaculture (cf. The "Green Revolution" in
agriculture). Our current genomic analysis to identify "fast growth genes" has obvious practical implications for aquatic food production.
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Research Keywords
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Animal environmental physiology; Biological adaptations to temperature and food; Biology of temperate, polar, tropical, and deep-sea species; Antarctic marine biol.; Hydrothermal vent biology; Developmental biology; Evolutionary biology; Marine invertebrate life history; Larval ecology; Aquaculture.
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Research Specialties
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Animal environmental physiology; Biological adaptations to temperature and food; Marine biology of temperate, polar, tropical, and deep-sea species; Antarctic marine biology; Hydrothermal vent biology; Developmental biology; Evolutionary biology; Marine invertebrate life history; Larval ecology; Aquaculture.
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Detailed Statement of Research Interests
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GENERAL THEME: My field of research is the environmental physiology of marine animals. My work bridges the fields of physiology, developmental biology, and molecular biology – all studied in an environmental context. Most marine animals have complex life history strategies and the larval stages are, in general, less well understood in comparison to adult phases of life cycles. I study larval biology from the perspective of environmental physiology, in particular how larvae 'work' in contrasting environments of temperature, food, and pressure (e.g., temperate and polar oceans, and hydrothermal vent environments). Such studies are required for understanding growth and development of animal stages, for studies of ecological recruitment, and for measuring dispersal potential in the ocean with respect to population connectivity. *** APPROACH: Research in my laboratory group combines some major fields of biological sciences, such as the functional analysis of organisms (i.e., the field of general physiology) and the field of comparative and integrative biology studied in the context of developmental biology. All of the marine biological questions in my research group are driven by oceanographic, evolutionary, and ecological questions that originate from observations at the level of the whole organism. My research program takes an integrative approach to the study of marine animal biology. In my case, the definition of the word "integrative" encompasses studies across multiple levels of biological analyses – from studies of the whole organism, to measuring physiological rate process, to the kinetics of complex molecules, and to the level of individual genes. I believe this broad approach to the study of environmental physiology is required for understanding the mechanistic bases of biological rate processes and physiological adaptation. *** RESEARCH EXAMPLES: How much of the observed biological variation in physiological rates in the ocean is a function of the environment? How much of this variation is genetically fixed? (issues of "Nature versus Nurture"). To answer these kinds of questions will require the incorporation into marine physiology of genomic and quantitative genetic approaches to the study of variation of rate processes at the level of the whole organism (e.g., physiological genomics to understand complex traits, such as size and growth rates in the sea). Currently, we are funded by the National Science Foundation’s "Biocomplexity" program in Genome-Enabled Environmental Science (Gen-En) to undertake genomic studies of larval physiology (see Pace et al., 2006. J. Exp. Mar. Biol. & Ecol.; and Hedgecock et al., 2007. PNAS [see "Publications" below for full references]). In addition to studies of animals from temperate regions, I have been actively involved in the study of physiological adaptations to "extreme environments" – such as pressure extremes at deep-sea hydrothermal vents and temperature extremes in polar oceans. We successfully cultured the hydrothermal vent tubeworm Riftia pachyptila to the larval stage to study larval physiology. Having this species in culture allowed for measurements of physiological processes in larvae and the development of physiological-physical dispersal models for this important species in hydrothermal vent environments (see Marsh et al., 2001. Nature). In the Southern Ocean, our studies of the physiology of Antarctic larvae resulted in the discovery of temperature adaptations for RNA and protein synthesis. We found that these cold-water organisms are capable of synthesizing proteins for 25-times less energy than has been reported for other animals (see Marsh et al., 2001. Science; and Pace and Manahan, 2007. Biol. Bull). The mechanisms of this unique physiology are now under active investigation. There are also some 'applied' aspects to some of our research. These include the search for ways to improve the production of food from the ocean for human consumption, through the application of "hybrid vigor" to enhance growth rates of marine mollusks (cf. heterosis and the "Green Revolution" in agriculture). Additionally, we have studied the larval forms of marine species on the Federal Endangered Species List (California White Abalone) in an effort to understand the larval biology of this species and to optimize culturing conditions for possible restoration projects (see Moran and Manahan, 2003. Biol. Bull.).
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Affiliations with Research Centers, Labs, and Other Institutions
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McMurdo Research Station, Antarctica, Field Team Leader (PI on NSF grants),http://antarctica.usc.edu
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USC Wrigley Institute for Environmental Studies, Director of research projects at the USC Marine Laboratory on Catalina Island,http://wrigley.usc.edu/
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Conferences and Other Presentations
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Conference Presentations
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"Extended starvation resistance and subsequent growth recovery in sea urchin larvae: Implications for lifespan in the plankton (Yu and Manahan)", Society of Integrative and Comparative Biology, Talk, 1/2008-
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"Genotype-dependent temperature physiology of larvae: Implications for range expansion (Curole, Berger & Manahan)", Society of Integrative and Comparative Biology, Talk, 1/2008-
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"An overview of biological research at the poles (D.T. Manahan)", International Polar Year: Smithsonian Institution, Talk, http://www.si.edu/ipy/speakers/manahan_ab.htm, 5/2007-
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"Physiological determinants of larval life span in the plankton (D.T. Manahan)", Ocean Science Research Conference, American Society of Limnology and Oceanography, Talk, 2/2007-
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"Amino acid transporter gene expression during sea urchin development (Meyer and Manahan)", Society of Integrative and Comparative Biology, Talk, 1/2007-
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"Ecophysiology of Antarctic sea urchin larvae (Pace and Manahan)", 7th International Larval Biology Conference, Talk, 8/2006-
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"Genetic and environmental determinants of growth rates in bivalve larvae (Meyer and Manahan)", 7th International Larval Biology Conference, Talk, 8/2006-
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"Larval dispersal potential: Physiological and genetic determinants of life span (D.T. Manahan)", 7th International Larval Biology Conference, Talk, 8/2006-
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"Maternal provisioning and genetic determination of metabolic-based starvation resistance (Yu and Manahan)", 7th International Larval Biology Conference, Talk, 8/2006-
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"Nutritional state of larvae in the ocean: an in situ study of sea urchin larvae (Manahan and Ginsburg)", 7th International Larval Biology Conference, Talk, 8/2006-
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Other Presentations
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"International Polar Year: The Federal Role", US Congressional Testimony (D.T. Manahan), US Congress, Committee on Science (Subcommittee on Research)., Washington DC, 9/2006-
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Other Research
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Video of lecture by Donal T. Manahan on "History of Polar Exploration and Science" (on NSF's International Polar Year web site):
http://www.us-ipy.gov/DesktopModules/Articles/ArticleDetails.aspx?ItemID=426
Lecture date, 2006-
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Publications
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Journal Article
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Hedgecock, D., Lin, J., DeCola, S., Haudenschild, C. D., Meyer, E., Manahan, D. T., Bowen, B.
(2007).
Transcriptomic analysis of growth heterosis in larval Pacific oysters (Crassostrea gigas). Proc. Natl. Acad. Sci. USA.
Vol. 104, pp. 2312-2318.
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Meyer, E., Green, A. J., Moore, M., Manahan, D. T.
(2007).
Food availability and physiological state of sea urchin larvae (Strongylocentrotus purpuratus). Marine Biology.
Vol. 152, pp. 179-191.
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Moore, M., Manahan, D. T.
(2007).
Variation among females in egg lipid content and developmental success of echinoderms from McMurdo Sound, Antarctica. Polar Biology.
Vol. 30, pp. 1245-1252..
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Pace, D. A., Manahan, D. T.
(2007).
Cost of protein synthesis and energy allocation during development of Antarctic sea urchin embryos and larvae. The Biological Bulletin.
Vol. 212, pp. 115-129.
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Pace, D. A., Manahan, D. T.
(2007).
Efficiencies and costs of larval growth in different food environments (Asteroidea: Asterina miniata). Journal of Experimental Marine Biology and Ecology.
Vol. 353, pp. 89-106.
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Pace, D. A., Manahan, D. T.
(2006).
Fixed metabolic costs for highly variable rates of protein synthesis in sea urchin embryos and larvae. Journal of Experimental Biology.
Vol. 209, pp. 158-170..
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Pace, D. A., Marsh, A. G., Leong, P. K., Green, A. J., Hedgecock, D., Manahan, D. T.
(2006).
Physiological bases of genetically determined variation in growth of marine invertebrate larvae: A study of growth heterosis in the bivalve Crassostrea gigas. Journal of Experimental Marine Biology and Ecology.
Vol. 335, pp. 188-209.
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Moran, A. L., Manahan, D. T.
(2004).
Physiological recovery from prolonged starvation in larvae of the Pacific oyster Crassostrea gigas. Journal of Experimental Marine Biology and Ecology.
Vol. 306, pp. 17-36.
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Moran, A. L., Manahan, D. T.
(2003).
Energy metabolism during larval development of green and white abalone, Haliotis fulgens and H. sorenseni. Biological Bulletin.
Vol. 204, pp. 270-277.
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Marsh, A. G., Mullineaux, L. S., Young, C. M., Manahan, D. T.
(2001).
Larval dispersal potential of the tubeworm Riftia pachyptila at deep-sea hydrothermal vents. Nature.
Vol. 411, pp. 77-80.
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Marsh, A. G., Maxson, R., Manahan, D. T.
(2001).
High macromolecular synthesis with low metabolic cost in Antarctic sea urchin embryos. Science.
Vol. 291, pp. 1950-1952..
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Marsh, A. G., Leong, P. K., Manahan, D. T.
(2000).
Gene expression and enzyme activities of the sodium pump during sea urchin development: Implications for indices of physiological state. Biological Bulletin.
Vol. 199, pp. 100-107.
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Honors and Awards
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Appointed a lifetime "National Associate" of the United States’ National Academies, 2001-
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A 6000-foot mountain in Antarctica named "Manahan Peak" for contributions to Antarctic research, education, and service to the science community., 2000-
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