CAREER: Physiological and Molecular Mechanisms of Cadmium and Temperature Action on Mitochondrial Bioenergetics in Marine Mollusks

University Of North Carolina At Charlotte, Charlotte NC

Investigators

Abstract

In today's world, geological forces have combined with past and present human activities to cause an extremely rapid environmental change, one that is often too strong and too fast to permit the long process of evolutionary adaptation that can require many generations to complete. The population survival and distribution of many species in this rapidly changing environment will depend on their abilities to cope with stress and to quickly adjust their physiology to environmental change. Metabolic regulation plays a key role in environmental stress tolerance of all organisms. An organism produces ATP, the main energetic currency of the cell, in its mitochondria to cover its needs for basal maintenance, growth, activity and reproduction. Impairment of mitochondrial function will have important consequences for performance and survival of the organism under stress conditions. This project will uncover fundamental physiological and molecular mechanisms of action of cadmium and elevated temperatures on the function of mitochondria in a model marine mollusk, the eastern oyster Crassostrea virginica. Cadmium and temperature, common environmental stressors in estuaries and coastal habitats, directly affect mitochondrial function. Poikilothermic ("cold-blooded") animals, which include most marine fish and invertebrates, may be especially prone to these stressors because they are exposed to varying temperatures and levels of cadmium in water and sediment. This project will use the eastern oyster as a model organism in order to: Obtain a comprehensive physiological model of temperature-dependent action of cadmium and to identify key mitochondrial targets for cadmium in poikilothermic animals, which are currently unknown; Determine how cadmium- and temperature-induced changes in mitochondrial function affect cellular and whole-organism metabolism; Determine whether exposure to one environmental stressor (e.g., temperature) can make an organism more sensitive to the other (e.g., cadmium) and vice versa. These results will provide important insights into the effects of multiple environmental stressors on metabolic regulation and physiological performance of marine poikilotherms and will allow a better understanding of the factors that limit adaptability of these organisms in the face of the rapid environmental change. While providing a strong environmental focus in the interdisciplinary graduate programs in the Department of Biology at UNC Charlotte, this project increases the quality of education through new Web-enhanced courses and through active recruitment of undergraduate and graduate students (including women and under-represented minorities) into research. Also included are active collaborative programs and student exchange with international partners in Canada and Germany and with a local minority undergraduate-level university.