Richards, Jeffrey - University of British Columbia

个人简介

B.Sc. (Hons) Department of Biology, Wilfrid Laurier University; M.Sc. Department of Biology, University of Waterloo; Ph.D. Department of Biology, McMaster University

研究领域

The primary goal of my research program is to understand the adaptive significance of the mechanisms coordinating cellular responses to stress. Specifically, I am interested in the physiological, biochemical, and molecular mechanisms that act to balance energy supply and demand during short- and long-term exposure to environmental stress and the signal transduction pathways responsible for coordinating acclimation. In organisms with the capacity to acclimate, exposure to an environmental stress induces a temporal cascade of events culminating in an enhanced ability to endure the newly imposed stress. This temporal cascade begins with the rapid and reversible modification of cellular proteins (e.g. phosphorylation & protein aggregation) followed by changes in gene expression (mRNA transcription and protein translation), both of which act to homeostatically optimize cellular pathways resulting in acclimation. To date, considerable research has focused on the impact of various environmental stressors on individual physiological or biochemical systems (e.g. effects of exercise on lactate production); however, little research has focused on the importance of a coordinated response to environmental stress across multiple pathways the signal transduction pathways involved in this response. I currently use hypoxia (low oxygen), exercise, and salinity transfer as ecologically relevant challenges to induce bioenergetic stress in fish. Fish are an excellent model to examine bioenergetics and adaptation to environmental stress because they routinely encounter harsh environmental conditions (e.g. hypoxia) and posses the physiological, biochemical and molecular framework to deal with these perturbations. During exposure to environmental stress, fish must coordinate changes in energy demand with changes in energy supply. Several candidate signal transduction cascades (e.g. mitogen activated protein (MAP) kinase and 5’AMP protein kinase (AMP kinase) pathways) are known to modify the activity of various rate limiting enzymes and transcription factors and thus facilitate acclimation. However, the relationship between signal transduction pathway organization and the coordinated response to environmental stress has not been examined, especially in the context of acclimation or adaptation. Thus, my research program integrates mechanistic physiology, utilizing model organisms and their available tools (microarrays, proteomics, phospho-antibodies, and pharmacological tools), with comparative physiology to put the mechanism into an environmental, ecological, and evolutionary context.

近期论文

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Mandic, M., Sloman, K. & Richards, J.. 2009. Escaping to the surface: A phylogenetically independent analysis of hypoxia-induced respiratory behaviors in sculpins. Physiological and Biochemical Zoology 82: 730-738 Mandic, M., Todgham, A.E. & Richards, J.G. 2009. Mechanisms and evolution of hypoxia tolerance in fish. Proceedings of Royal Society - B. 276:735-744 Scott, G.R. Egginton, S. Richards, J.G. and Milsom, W.K. 2009. Evolution of muscle phenotype for extreme high altitude flight in the bar-headed goose. Proceedings of the Royal Society - B 276: 3645-3653 Hallman, T.M., Rocha, A., Jones, D.R., and Richards, J.G. 2008. Metabolic recovery from exercise and hypoxia exposure measured using 31P- and 1H-NMR in the common carp, Cyprinus carpio. Journal of Experimental Biology 211:3237-3248 Henriksson, P., Mandic, M., and Richards, J.G. 2008. The osmo-respiratory compromise in sculpins: a respiratory compromise is essential for freshwater tolerance. Physiological and Biochemical Zoology. 81: 310-319 Jibb, L.A. and Richards, J.G. 2008. AMP-actiated protein kinase activity during metabolic rate depression in the hypoxic goldfish, Carassius auratus. Journal of Experimental Biology. 211: 3111-3122 Mandic, M., Lau, G., Nijjar, M., and Richards, J.G. 2008. Metabolic recovery in goldfish: a comparison of recovery from severe hypoxia exposure and exhaustive exercise. Comparative Biochemistry and Physiology 148C: 332.338 Richards, J.G., Sardella, B.A. and Schulte, P.M. 2008. Regulation of pyruvate dehydrogenase in the common killifish, Fundulus heteroclitus during hypoxia exposure. American Journal of Physiology. 295: R979-R990 Sloman, K.A., Mandic, M., Todgham, A.E., Fangue, N.A., Subrt, P., and Richards, J.G. 2008. The response of the tidepool sculpin, Oligocottus maculosus, to hypoxia in laboratory, mesocosm and field environments. Comparative Biochemistry and Physiology 149A: 284-292