Snow crab (Chionoecetes opilio) hemocytes and hepatopancreas transcriptomes: identification of candidate molecular biomarkers of exposure to chronic noise

In the marine environment, snow crab (Chionoecetes opilio) are subjected to noise from marine industries (e.g. ship activities and seismic noise from hydrocarbon exploration). This project investigated the potential impact of exposure to chronic noise in a laboratory setting on the hemocytes and hepatopancreas transcriptomes with a focus on immune, digestion, metabolism and stress-response relevant gene expression. Briefly, wild captured, terminally-molted, commercial size, male snow crab were held in duplicate control or experimental tanks at an aquarium facility in the Northwest Atlantic Fisheries Centre, Fisheries and Oceans Canada, St. John’s, NL. On alternating days, the experimental tanks were exposed to impulse sound (approximately 200 dB at 1 µPA) from a seismic soundtrack played through an underwater speaker (Lubell Labs, Model LL9161) for 22 weeks. RNA was isolated from the hemocytes and hepatopancreas of 5 crab from each of the duplicate control tanks and of 5 crab from each of the duplicate experimental tanks, and subjected to RNA sequencing (RNAseq) analyses. Candidate noise-responsive molecular biomarkers were identified using DESeq2 (FDR < 0.05) and expression levels of selected transcripts were validated using real-time quantitative polymerase chain reaction (qPCR) analyses.