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Isaac WirginAssociate Professor, Department of Environmental Medicine
57 Old Forge Rd.
Tuxedo, NY 10987
The Atlantic tomcod, Microgadus tomcod, from the Hudson River provides a unique opportunity to study the molecular aspects of genetic susceptibility to neoplasia in an outbred model organism that 1) exhibits an unusually high prevalence of hepatocellular carcinomas (more than 90% in 2-yr-old fish), 2) is exposed to high levels of environmentally borne chemical carcinogens, and 3) can be used to investigate the effects of controlled laboratory model-chemical exposures on sensitive early-life stages.
We examined the effects of the interactions of genetic variation and exposure to high levels of Hudson River-borne xenobiotics on the structure and expression of carcinogenically relevant genes, such as K-ras, aromatic hydrocarbonreceptor (Ahr) and cytochrome P4501A (CYP1A1). We found activated K-ras in a high percentage of tomcod liver-tumor DNAs, a transcribed genetic polymorphism in the 3' untranslated region of CYP1A1 in Hudson River tomcod that is not observed in cancer-free populations of tomcod.
Currently, we study the functional significance of genetic variation in this model relevant to: 1) the role of K-ras oncogene activation in early neoplastic events and hepatocarcinogenesis progression in tomcod livers, 2) the effects of environmentally relevant polychlorobiphenyl (PCB) promotion on clonal expansion of initiated cells, and 3) the molecular mechanisms of CYP1A1 gene regulation in environmentally exposed tomcod from the Hudson River. We also explore the effects of inter-specific and inter-individual differences in Ahr gene expression levels on CYP1A1 gene expression and transcription inhibition in halogenated aromatic hydrocarbon-exposed fish.
Research Keywordsmolecular mechanisms of carcinogenesis in Hudson River tomcod
Status and Genetic Character of Atlantic Sturgeon in the Satilla River, Georgia
Fritts, Mark W; Grunwald, Cheryl; Wirgin, Isaac; King, Tim L; Peterson, Douglas L. Status and Genetic Character of Atlantic Sturgeon in the Satilla River, Georgia. Transactions of the American Fisheries Society. 2016 ;145(1):69-82 (2019602)
Microsatellite DNA analysis of spatial and temporal population structuring of Phragmites australis along the Hudson River Estuary
Stabile, Joseph; Lipus, Daniel; Maceda, Lorraine; Maltz, Michele; Roy, Nirmal; Wirgin, Isaac. Microsatellite DNA analysis of spatial and temporal population structuring of Phragmites australis along the Hudson River Estuary. Biological invasions. 2016 SEP;18(9):2517-2529 (2257162)
Genetic variation and population structure of American mink Neovison vison from PCB-contaminated and non-contaminated locales in eastern North America
Wirgin, Isaac; Maceda, Lorraine; Waldman, John; Mayack, David T. Genetic variation and population structure of American mink Neovison vison from PCB-contaminated and non-contaminated locales in eastern North America. Ecotoxicology. 2015 Nov;24(9):1961-1975 (1779252)
Population origin of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus by-catch in U.S. Atlantic coast fisheries
Wirgin, I; Maceda, L; Grunwald, C; King, T L. Population origin of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus by-catch in U.S. Atlantic coast fisheries. Journal of fish biology. 2015 Apr;86(4):1251-1270 (1565632)
Origin of Atlantic Sturgeon Collected off the Delaware Coast during Spring Months
Wirgin, Isaac; Breece, Matthew W.; Fox, Dewayne A.; Maceda, Lorraine; Wark, Kevin W.; King, Tim. Origin of Atlantic Sturgeon Collected off the Delaware Coast during Spring Months. North American journal of fisheries management. 2015 ;35(1):20-30 (1559972)