Title: CYP1A1 Gene Expression Verification Study – Re-Evaluation of Sea Otter Samples from the Exxon Valdez Oil Spill
Project Year and Number: 2009: 090841
Other Fiscal Years and Numbers for this Project: None
Principal Investigator (PI): Keith Miles, US Geological Survey
Assisting Personnel: Brenda Ballachey
Research Location: Western Prince William Sound
Restoration Category: Research
Injured Resources Addressed: Not Specified
Abstract: Sea otter populations in western PWS were injured as a result of the Exxon Valdez oil spill, with evidence for both immediate acute mortality and longer term injury from chronic exposure to oil spilled in 1989. The EVOS Trustee Council funded over a decade of studies to identify progress toward recovery of the sea otter populations, particularly in the northern Knight Island Archipelago. These projects have addressed population demographics including abundance, habitat use, and survival rates, together with biological sampling to monitor body condition using blood parameters, liver pathology, and a CYP1A biomarker to determine oil exposure. Although population abundance data indicate some level of recovery in Prince William Sound overall, recovery remained incomplete as of 2006. Recently, a 2002 report (Snyder et al.) of the CYP1A biomarker assessments of sea otter exposure to oil has been questioned, making it necessary to reevaluate this method for assessing exposure. In this study, we propose to re-test the exposure of sea otters to lingering oil by applying our recent discoveries of sea otter specific genetic primers to measure gene expression on the archived samples from these projects. Our initial studies of mink experimentally exposed to oil identified genes that were significantly altered in expression (Bowen et al. 2007). These genes play a role in immuno-modulation, inflammation, cyto-protection, tumor suppression, reproduction, cellular stress-response, metal metabolism, xenobiotic metabolizing enzymes, antioxidant enzymes, and cell-cell adhesion. We have successfully sequenced 13 genes from sea otters that were expressed in mink experimentally exposed to oil, as well as 2 additional genes that aid interpretation of stress levels in animals exposed to xenobiotics that include aromatic hydrocarbons. In phase one of the project, we will analyze the gene expression of a suite of genes from archived Peripheral Blood Mononuclear Cells (PBMC) and liver samples collected from individual sea otters in 2003-2006. If these PBMC samples produce meaningful analytic results, the project will proceed with phase two, to analyze the gene expression in PBMC samples from 1996 through 2002. This study will allow us to verify our past understanding of oil exposure of sea otters in PWS, assess the current status of recovery, and provide a reliable method for assessing recovery in the future.
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Final Report: Final Report Not Available - For Current Status Please Contact Us
Publications from this Project: None Available