Lisa Crockett, Ph.D.

     I am broadly interested in adaptational physiology and biochemistry. My interests center on mechanism, and specifically, what adjustments in metabolism and properties of biological membranes enable organisms to live in physically challenging environments. Much of my research to-date examines some of the physiological/biochemical underpinnings promoting tolerance to 1) chronically low body temperatures (Antarctic fishes), 2) variation in body temperature (temperate ectotherms), 3) changing salinities (euryhaline fish).

     A current NSF-funded research project (in collaboration with R. Patrick Hassett, also in the Department of Biological Sciences) involves elucidating the nutritional and membrane requirements for cholesterol in zooplankton. In order to understand dietary factors that limit growth it is necessary to identify key components in the diet and define the conditions under which these components become limiting. One biomolecule that has never systematically been tested as a possible limiting factor is cholesterol and its sterol precursors. Requirements for cholesterol in animals are likely to be driven largely by contents of cholesterol in plasma membranes. We are 1) identifying the physical and biotic conditions for which dietary sterols become limiting in zooplankton, and 2) defining the coupling between dietary and membrane-specific cholesterol contents.

Selected References:

• Crockett, E.L., B.E. Dougherty, A.N. McNamer. 2001. Effects of acclimation temperature on enzymatic capacities and mitochondrial membranes from the body wall of the earthworm Lumbricus terrestris. Comp. Biochem. Physiol. B, in press.

• Hassett, R.P. and E.L. Crockett. 2000. Endpoint fluorometric assays for determining activities of carnitine palmitoyltransferase and citrate synthase. Anal. Biochem. 287: 176-179.

• Crockett, E.L., R.L. Londraville, E.E. Wilkes, and M.C. Popesco. 1999. Enzymatic capacities for beta-oxidation of fatty fuels are low in the gill of teleost fishes despite the presence of fatty acid-binding protein. J. Exp. Zool. 284: 276-285.

• Crockett, E.L. 1999. Lipid restructuring does not contribute to elevated activities of Na+/K+-ATPase in basolateral membranes from the gill of seawater-acclimated eel (Anguilla rostrata). J. Exp. Biol. 202: 2385-2392.

• Gibbs, A.G. and E.L. Crockett. 1998. The biology of lipids: integrative and comparative aspects. Am. Zool. 38: 265-267.

• Crockett, E.L. 1998. Cholesterol function in plasma membranes from ectotherms: Membrane-specific roles in adaptation to temperature. Am. Zool. 38: 291-304.

• Crockett, E.L. and J.R. Hazel. 1997. Cholesterol affects physical properties and (Na+, K+)-ATPase in basolateral membranes of renal and intestinal epithelia from thermally acclimated rainbow trout.  J. of Comparative Physiology B 167:344-351.