Jim Staples, PhD
Comparative Physiology and Biochemistry
My research program aims to understand how the metabolic systems of animals adapt to environmental challenges. In particular I am interested in the strategies used by endothermic animals to deal with cold environments. When challenged by the cold, most endotherms increase metabolic rate and heat production. We study enzymatic and mitochondrial “futile cycles” in bumblebees and rats as possible mechanisms of non-shivering thermogenesis.
Some small endotherms use an apparently opposite strategy by entering hibernation or torpor during the coldest parts of the year. These states involve profound reductions of body temperature and metabolic rate, allowing for energetic savings at a time when food supplies are typically at their lowest. We study mitochondrial metabolism in hibernation (using ground squirrels) and daily torpor (using dwarf Siberian hamsters) to better understand the mechanisms of metabolic suppression, and potential interactions with temperature and diet.
Degrees and Institutions
- BSc (Marine Biology), University of Guelph
- PhD (Zoology), University of British Columbia
- Biology 3220Z/4257Z/4258Z: Field Studies in Biology (Experimental Studies in Marine Biology)
- Biology 3602B: Animal Physiology II
- MacMillan, H.A, Williams, C.M., Staples, J.F. and Sinclair, B.J. Reestablishment of ion homeostasis during chill-coma recovery in the cricket Gryllus pennsylvanicus. Proc. Nat.Acad. Sci., in press.
- Gallagher, K. and Staples, J.F. Metabolism of brain cortex and cardiac muscle mitochondria in hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus). Physiol. Biochem.Zool. in press.
- Brown, J, Marshall, K., Staples, J. 2012. Differences in tissue concentrations of hydrogen peroxide in the roots and cotyledons of annual and perennial species of flax (Linum). Botany. 90(10): 1015-1027.
- Suri L., McCaig L., Picardi, M., Ospina, O., Veldhuizen, R., Staples, J., Possmayer, F., Yao,L., Perez-Gil, J., Orgeig, S. 2012. Adaptation to low body temperature influences pulmonary surfactant composition thereby increasing fluidity while maintaining appropriately ordered membrane structure and surface activity. BBA-Biomembranes. 1818:1581-1589.
- MacMillan, H.A, Williams, C.M., Staples, J.F. and Sinclair, B.J. 2012. Metabolism and energy supply below the critical thermal minimum of a chill-susceptible insect. J. Exp. Biol. 215:1366-1372.