UNIVERSITY OF NORTH CAROLINA AT CHARLOTTE
LiT: Interactive Effects of Multiple Environmental Stressors on Mitochondrial Metabolism and Bioenergetics in a Model Marine Ectotherm, Crassostrea virginica
While among the most productive areas of the ocean, estuaries and coastal zones often suffer a high degree of environmental stress from naturally-occurring changes in salinity, temperature, pH, oxygen content as well as manmade stresses caused by the dumping of pollutants and nutrients, which can cause toxicity in marine organisms and/or lead to oxygen-depleted 'dead zones'. The survival of marine organisms depends on the flexibility of their stress tolerance mechanisms, which adapt to handle most natural changes, but manmade changes happen too quickly for evolutionary adaptation to occur. Energy metabolism plays a key role in these adaptations. Currently, the interactive effects of multiple stressors on energy metabolism of marine organisms in an environmentally-realistic context are not well understood because most studies focus on the effects of a single stressor. This study will help close this significant gap in knowledge by exploring the basic physiological and molecular mechanisms of the interactive effects of three stressors commonly found in estuaries and coastal zones (intermittent anoxia, or lack of oxygen; a trace metal, cadmium; and temperature stress) on the energy metabolism of a model marine mollusk, the eastern oyster Crassostrea virginica. Oysters, which are major ecosystem builders and play an important role in the economies of the eastern US coastal states, can survive environmental extremes, making them excellent model organisms for this study. THE STUDY involves a comprehensive analysis of aerobic (mitochondrial) and anaerobic metabolism and will significantly advance the field of metabolic physiology by providing an integrative picture of metabolic change during environmentally-realistic stress exposures that can be quantitatively and qualitatively different than the effects of single stressors. Moreover, because energy metabolism is central to the survival and stress tolerance of all organisms and mitochondrial functions are highly conserved in evolution, the project results can be extrapolated beyond oysters to yield important new insights into the fundamental mechanisms of mitochondrial stress responses of marine invertebrates in general. This project will have important educational impacts by involving undergraduate, graduate, K-12 students and a post-doc, including women and underrepresented minorities, into research; strenghtening an environmental focus in the interdisciplinary PhD program in Biology at the University of North Carolina at Charlotte; and fostering active collaborative programs and student exchanges between UNC Charlotte and Johnson C. Smith University, a local minority undergraduate-level university.