David C. Pfeiffer, Ph.D. Associate Professor of Biological Sciences Department of Biological Sciences University of Alaska Anchorage

Biographical Information Postdoctoral research, University of Utah Department of Biology Ph.D./Anatomy 1997 University of British Columbia, Canada M.Sc./Anatomy 1990 University of British Columbia, Canada B.A./Biological Sciences 1987 University of North Carolina Charlotte, NC

GENERAL RESEARCH INTERESTS:

Much of the research interest of my laboratory falls within the field of functional morphology - the study of the structural and functional adaptations organisms display in relation to the environments in which they live. We approach morphology from the molecular and cellular levels of organization through the tissue level of organization. Frequently we look to the field of physiology in order to fully explain the particular adaptations of a cell, tissue and/or entire organism. On-going projects in my laboratory are focused on topics such as the physiology of stress in marine mammals (the structural and functional changes brought on by short-term or long-term stress), thermoregulation in the walrus (structural/functional adaptations for temperature regulation), and the comparative cell biology of adhesion junctions (evolution of different strategies for intercellular adhesion).

CURRENT RESEARCH PROJECTS:

The Physiology of Stress in Marine Mammals
Exaggerated stress-induced responses in stranded marine mammals often lead to cell or tissue-level injury and contribute to the overall deterioration and/or death of many animals. We are interested in understanding more fully the structural/functional basis of the stress response (alarm response) in cetaceans. We are studying the short-term responses and long-term adaptations to stress in small cetaceans such as the Atlantic bottlenose dolphin (Tursiops truncatus). Funded by grants from the National Oceanic and Atmospheric Administration/National Marine Fisheries Service

Thermoregulation in the Walrus
The walrus is a master when it comes to temperature regulation. The walrus is essentially "naked" (lacks a protective pelage), yet during winter months it is able to haul out on ice in temperatures as low as -30oC without developing frostbite. During summer months it is able to haul out on sun-warmed rocks (as warm as 25oC) without succumbing to hyperthermia. We are interested in the underlying structural and functional adaptations that permit the walrus to thermoregulate in the temperature extremes of its arctic environment. Funded by a UAA Faculty Development Grant

Comparative Cell Biology of Adhesion Junctions
One of the fundamental requirements for multicellular organization is that cells must possess mechanisms for intercellular adhesion; that is, cells must be able to selectively establish and maintain attachment sites with one another. A variety of mechanisms have evolved that meet this demand. One common mechanism involves the incorporation of elements of the cell's cytoskeleton into the process of intercellular adhesion at well-defined junction sites (adherens junctions, desmosomes). We are interested in how cells construct and maintain intercellular junctions as well as how different strategies for adhesion have evolved in different classes of vertebrates. Much of our interest has focused on intercellular adhesion mechanisms within the seminiferous epithelium of the male reproductive tract. Here some very unusual strategies for intercellular adhesion have evolved. Funded by a UAA Faculty Development Grant