The structural and functional properties of cytochrome P450 proteins and their regulation will be examined for a number of Antarctic fish species. These proteins are critical in the metabolism and biological action of many hormones, as well as pollutants and carcinogens. Some of these proteins are induced by pollutant chemicals and are ideal markers for exposure. The genes for several P450 proteins, and the gene products will be studied. The P450 that is induced by hydrocarbons or polychlorinated biphenyls and the receptors involved in the regulation of the gene will be characterized. The objectives are to identify structural and functional adaptions of membrane bound enzymes, their gene regulation and receptor mechanisms in stenothermal cold-adapted animals. Additional objectives are to provide a molecular and mechanistic basis for evaluating the degree to which foreign chemicals may be acting in Antarctic fish. These studies should provide a definitive baseline and archival samples of numerous species, against which results of future samples and analyses can be compared. The results will have implications for detecting and following the present and future effects of chemicals in the Southern Ocean and may distinguish between chemicals with global and/or local Antarctic sources.
