Christopher Z. Womersley
Professor Emeritus, Biology
Physiological Ecology/Adaptive Biochemistry; Dehydration and Freezing Stress; Biological Control
Awards & Honors
Regents Medal for Excellence in Teaching, 1993
Access to College Experience (ACE) Professor Of The Year, 1997
My research focus is the study of the physiological/biochemical adaptations in response to extreme environmental stress. While various types of environmental stresses are studied, my research utilizes those animals that are able to tolerate dehydration stress as a model system. Essentially all animals are able to tolerate drying to some degree, but relatively few are able to survive extreme dehydration (removal of all body water), while still retaining structural and functional integrity. This is accomplished by entry into a dormant state of "suspended animation", called anhydrobiosis. The problem of anhydrobiotic survival, how this condition is attained and maintained, and how animals adapt to its effects has, until relatively recently been poorly understood, and comparative biochemical/biophysical studies on anhydrobiotic organisms are still in their infancy.
My laboratory is one of the very few attempting such studies on multicellular organisms. I feel that, in terms of basic biology, these studies are of paramount importance in unraveling the mystery of anhydrobiotic survival and providing a deeper understanding of how water functions in fully hydrated systems. They may also provide new insights and directions to studies in applied fields.
Presently we are examining the role of carbohydrates in stabilizing a variety of biological systems during periods of low water activity. These include nematodes, tardigrades and rotifers. Such comparative studies have allowed us to question the accepted dogma that trehalose production is the specific metabolic adaptation necessary for stabilization and has led to findings that specific membrane components (i.e., phospholipids) can also be readily adapted to provide more stable membrane structures.
We are also actively researching the aging process itself - how this is controlled or even negated during cryptobiosis through behavioral, morphological and adaptive biochemical studies.
Other research projects include theoretical studies on the possibilities of extraterrestrial life. More specifically, we are concentrating on one of the satellite moons of Jupiter, Europa, and the kinds of biomolecules/cells that may exist in the supersaturated brine that is known to persist under its mosaic fractionated ice sheet.
Womersley, C.Z, Wharton, D. and Higa, L.M. (1998). Survival Biology. In. Physiology and Biochemistry of Plant Parasitic and Free-living Nematodes. (Perry, R.N. and D.J. Wright, eds.) CABI Press, pp. 271-302.
Womersley, C.Z. (1993). Factors affecting physiological fitness and modes of survival employed by dauer larvae and their relationship to pathogenicity. In : Nematodes and the biological control of insect pests. (Bedding, R.A., Akhurst, R., and Kaya, H.K. eds.), CSIRO Press, pp. 79-88.
Womersley, C.Z. (1990). Dehydration survival and anhydrobiotic potential. In Entomopathogenic Nematodes in Biological Control. (R. Gaugler & H.K. Kaya, eds.), CRC Press, pp. 117-137.
Guitierrez, L.M. and C.Z. Womersley (2000). Shadow responses and the possible role of dermal receptors in the Hawaiian black snail, Nerita picea (Gastropoda: Neritidae). The Veliger, 44 (1): 1-7.
Hill, K.T. and Womersley, C.Z. (1998). Fluorescent age-pigment accumulation and the use of multiple regression models for age estimation in two fish species. J. Exp. Mar. Biol. Ecol. (in press).
Womersley, C.Z., Higa, L.M. and Leonhardt, K.W. (1998). Entomopathogenic nematodes: Where they live, why they kill insects and ways to improve their biocontrol potential of insect pests in a protected Hawaiian Floriculture setting. Proceedings Fourth Multicommodity Cutflower Industry Conference, HITAHR (in press).