Jim StaplesAssociate
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Teaching
- Environmental Animal Physiology (Bio 351a)
- Topics in Physiology (Bio 410G)
- Honours Biology (Bio 499)
- Experimental
Marine Biology (Bio 320y/420y) at the Huntsman Marine Science Centre in
Research
Comparative Metabolic Biochemistry
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Mammalian Hibernation and Cold-Acclimation: Many species of small mammals, such as this 13-lined Ground Squirrel (Spermophilus tridecemlineatus), survive winters by entering hibernation. During hibernation body temperatures may fall below freezing and metabolic rates are reduced by over 90%, conditions that would kill most mammals. My research examines the nature of this metabolic reduction at the cellular, mitochondrial and enzyme level. We are also studying how mitochondrial metabolism changes during cold-acclimation in non-hibernating mammals |
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Insect Muscle Metabolism: During flight insects such as this Bumblebee (Bombus spp.) produce some of the highest mass specific metabolic rates among animals. Our research indicates that during routine flight, many oxidative and glycolytic enzymes work close to their maximal capacities. In contrast, maximal exercise in most vertebrates rarely employs more than 20% of enzyme capacity. It appears that the metabolic components of these high-performance insects are pushed close to the design constraints of the system as a whole. We also research enzymes systems in bumblebees that may help them produce heat in cold climates. |
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Hypoxia Tolerance in Nautilus: The chambered Nautilus (Nautilus pompilius) lives on steep fore-reef slopes of coral islands in the southern Pacific and eastern Indian oceans. Although they may come as shallow as 75m at night, they retreat to the depths (up to 600m) during the day. Oxygen content may be low at these depths. In addition when threatened Nautilus retreat into their shells and cannot ventilate their gills. Therefore it is not surprising that these cephalopod molluscs can tolerate several hours of severe hypoxia. Research with Dr. Bob Boutilier suggests that this hypoxia tolerance is largely due to a reduced metabolic rate as ambient oxygen falls. Nautilus may also be able to use its shell as a SCUBA tank, exploiting the large oxygen stores contained in its chambers. |
Students
Graduate
Students
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Jason Brown M.Sc. candidate |
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Alex Gerson M.Sc. candidate
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Graduate Opportunities
I am always on the lookout for promising students who are interested in pursuing graduate studies with me. As prospective students would probably be researching mechanisms of metabolic suppression in hibernation and daily torpor, they should have a strong background in metabolic biochemistry and physiology. If you are interested, please send a CV and most recent transcripts by e-mail or to the address above.
Information for Prospective Students
Some advatages to pursuing Graduate Studies in Biology at UWO:
- guaranteed Teaching Assistant funding
- guaranteed summer support
- several internal scholarships (for more information click here)
- Graduate Tuition Scholarships for NSERC scholarship holders (for more information click here)
- Society of Graduate Students - student government by and for graduate students (link)
- Graduate Teaching Assistant's
- Grad Club: run by SOGS, it's a great place to meet friends and relax.
If you have any question e-mail
me or our graduate coordinator.
NSERC: For Students
and Fellows
Muleme, H. M,
West, T.G., Donohoe, P.H., Staples,
J.F. and Askew,
G.N. 2006. The role of
skeletal muscle in the hypoxia induced responses of submerged frogs., J. Exp. Biol. 209:1159-1168.
Schaefer, C. D. and Staples, J. F. 2006.
Mitochondrial metabolism in mammalian cold acclimation: magnitude and
mechanisms of fatty acid induced uncoupling. J. Therm.
Biol. 31(4):355-361.
Staples, J. F., Webber, D. M. and Boutilier, R. G.
2003. Environmental hypoxia does not constrain the diurnal depth distribution
of free-swimming Nautilus pompilius. Physiol. Biochem. Zool. 76(5):644-651.
Staples, J. F., Hershkowitz, J. J. and Boutilier, R. G. (2000). Effects of ambient PO2 and temperature on oxygen uptake in Nautilus pompilius. J. Comp. Physiol. B. 170(3):231-236.
Suarez, R. K., Staples, J. F., Lighton, J. R. B. and Mathieu-Costello, O (2000). Mitochondrial function in flying honeybees (Apis mellifera): respiratory chain enzymes and electron flow from complex III to oxygen. J. Exp. Biol. 203:905-911.
Suarez, R. K., Staples, J. F. and Lighton, J. R. B. (1999). Turnover rate of mitochondrial respiratory chain enzymes in flying honeybees (Apis mellifera). J. Exp. Zool. 284(1):1-6.
Staples, J. F. and Hochachka, P. W. (1998). The effect of hibernation status and cold-acclimation on hepatocyte gluconeogenesis in the golden-mantled ground squirrel (Spermophilus lateralis). Can. J. Zool. 76(9):1734-1740.
Hochachka, P. W., McClelland, G.B., Burness, G.P., Staples, J.F. and Suarez, R.K. (1998) Integrating metabolic pathway fluxes with gene-to-enzyme expression rates. Comp. Biochem. Physiol. B. 120(1):17-26.
Staples, J. F. and Suarez, R. K. (1997). Honeybee flight muscle phosphoglucose isomerase: Matching enzyme capacities to flux requirements at a near-equilibrium reaction. J. Exp. Biol. 200:1247-1254.
Staples, J. F. and Hochachka, P. W. (1997). Liver energy metabolism during hibernation in the golden-mantled ground squirrel, Spermophilus lateralis. Can. J. Zool. 74(7):1059-1065.
Suarez,
R. K., Staples, J. F., Lighton,
J. R. B. and West, T. G. (1997). Relationships between enzymatic flux
capacities and metabolic flux rates: Nonequilibrium
reactions in muscle glycolysis. Proc. Natl. Acad. Sci. 94:7065-7069.
Last revised: 11 May 2007