Differential Expression of CYP1A Protein in Populations of Fundulus grandis from Barataria Bay, Louisiana, Following the Deepwater Horizon Oil Spill

Landfall of crude oil from The Deepwater Horizon oil spill has been most pronounced in coastal areas of Louisiana. Among the most affected areas is Barataria bay, where heavily oiled marshland is still common place. The Gulf killifish (Fundulus grandis) is one of the most abundant species in coastal Louisiana marshlands and have high home range fidelity making them ideal species for observation of site-specific differences in physiological response to exposure to crude and weathered oil. Seven reference sites and 7 oiled sites were chosen across Barataria Bay, where F. grandis were collected during July, August, November, and December of 2010. Select tissues were processed for immunohistochemical localization and degree of CYP1A1 expression using monoclonal antibody C10-7 as a biomarker of exposure to PAHs. Site specific differences in CYP1A expression were found between oiled and reference locations. The most pronounced differences were found in the intestine, gills, and head kidneys. These studies provide a critical foundation for future endeavors to monitor effects, and to follow remediation of the Barataria Bay and other affected areas in Louisiana. Presently, we are examining physiological differences in fish from these locations to examine effects of exposure to crude oil.