Meeting Abstract

P1.15  Wednesday, Jan. 4  Identification of Several Glutathione S-transferase and Multixenobiotic Resistance Transporter Genes from the American Oyster, Crassostrea virginica PINKERTON, Mark*; TAPLEY, Jeffrey; CUNNINGHAM, Charles; JENNY, Matthew J; University of Alabama; University of Alabama; University of New Mexico; University of Alabama mjjenny@bama.ua.edu

Estuarine systems along the Gulf of Mexico were severely impacted by the ~5 million barrels of crude oil released from Deepwater Horizon oil spill in the Spring-Summer of 2010. Although biomarker genes indicative of hydrocarbon exposure are well characterized in vertebrate models, invertebrate responses are poorly understood. In an effort to identify novel invertebrate biomarkers of oil exposure, we chose the American oyster (Crassostrea virginica) as our model organism because of their sessile nature and capacity for bioaccumulation of pollutants. To identify candidate genes, oysters were exposed to crude oil (100 ppm) or crude oil and dispersant (1 ppm) for four days prior to tissue dissection (digestive gland and gill) used to produce the RNA template for next generation sequencing with the 454 Genome Sequencer. ~700,000 sequences reads were generated from each tissue, assembled into contigs and further annotated by comparison to the NCBI nonredundant database using the blastx algorithm. From these results we were able to identify several candidate members (cytoplasmic, and microsomal classes) of the glutathione S-transferase (GST) family, classic phase II metabolism genes involved in the biotransformation of xenobiotics. We also found several candidate multixenobiotic resistance (MXR) transporters that confer resistance by functioning as efflux transporters. These data represents the first extensive identification of these important detoxification genes from a mollusk. Gene expression studies with both controlled oil exposures (0.1 to 100 ppm) and oysters collected from oil-impacted reefs are currently underway to assess the feasibility of these genes as potential biomarkers of crude oil exposure.