Gene expression profiling in the deep water horse mussel Modiolus modiolus (L.) located near a marine municipal wastewater outfall

The marine bivalve Modiolus modiolus (L.) is a sentinel species used for the assessment of potential biological exposure to anthropogenic contaminants in benthic environments. Herein, we have developed real-time quantitative polymerase chain reaction assays for 12 specific mRNAs. The levels of each mRNA transcript were evaluated in adductor muscle, gonad, and hepatopancreas tissue collected from animals located at a reference site and a site near a preliminary municipal wastewater treatment outfall. Significant differences in mRNA abundance in animals located at the wastewater outfall site were observed for CAT and NET/SCF6 in all three tissues examined, ABCA4 and HSP70 transcript abundance were increased in the adductor muscle and hepatopancreas, respectively. Transcript levels for MDR, CYP4, rpS4, rpS9, and Ca2+-ATPase were not different between sites in the three tissues examined. This study sets the foundation for further evaluation of these transcripts’ utility in the evaluation of effluent effects within the marine environment.