Jeffrey Richards

Full Professor

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.

President’s Medal from the Society for Experimental Biology

2009
/
For Research

Boutilier New Investigator Award from the Canadian Society of Zoologists

2009
/
For Research
Naked mole rat brain mitochondria electron transport system flux and H+ leak are reduced during acute hypoxia
Journal of Experimental Biology
Pamenter, M.E., Lau, G.Y., Richards, J.G. and Milsom, W.K.
2018
Mitochondrial responses to prolonged anoxia in Western painted turtle brain.
Biology Letters 12:20150797
Pamenter, M.E., Gomez, C.R., Richards, J.G. and Milsom, W.K.
2016
Escaping to the surface: A phylogenetically independent analysis of hypoxia-induced respiratory behaviors in sculpins
Physiological and Biochemical Zoology 82: 730-738
Mandic, M., Sloman, K. & Richards, J.
2009
Evolution of muscle phenotype for extreme high altitude flight in the bar-headed goose
Proceedings of the Royal Society B 276: 3645-3653
Scott, G.R. Egginton, S. Richards, J.G. and Milsom, W.K
2009
Mechanisms and evolution of hypoxia tolerance in fish
Proceedings of Royal Society - B. 276:735-744
Mandic, M., Todgham, A.E. & Richards, J.G
2009
AMP-actiated protein kinase activity during metabolic rate depression in the hypoxic goldfish, Carassius auratus
Journal of Experimental Biology. 211: 3111-3122
Jibb, L.A. 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
Hallman, T.M., Rocha, A., Jones, D.R., 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
Mandic, M., Lau, G., Nijjar, M., and Richards, J.G
2008
Regulation of pyruvate dehydrogenase in the common killifish, Fundulus heteroclitus during hypoxia exposure
American Journal of Physiology 295: R979-R990
Richards, J.G., Sardella, B.A. and Schulte, P.M
2008
The osmo-respiratory compromise in sculpins: a respiratory compromise is essential for freshwater tolerance
Physiological and Biochemical Zoology. 81: 310-319
Henriksson, P., Mandic, M., and Richards, J.G
2008