Transcriptomic responses and oxidative stress in sub-adult red drum (Sciaenops occellatus) given a crude oil contaminated feed

To enhance understanding of the liver transcriptomic responses of dietary polycyclic aromatic hydrocarbon (PAH) exposure, red drum (Sciaenops ocellatus) were given crude oiled feed for 14 days. Differential expressed gene analysis demonstrated that 199 genes were significantly impacted in the oiled-fed red drum; 129 up-regulated, and 70 down-regulated. The up-regulated genes were primarily involved in DNA binding/transcription and cholesterol biosynthesis, whereas gluconeogenesis/glycolysis, immune/inflammation, and xenobiotic metabolism were mainly down-regulated. Ingenuity Pathway Analysis predicted 200 altered pathways in the oil-exposed fish. However, only seven pathways predicted directionality (all activated) associated with cholesterol biosynthesis. "Superpathway of Cholesterol Biosynthesis" exhibited the most robust prediction. Measuring oxidative stress biomarkers in the blood indicated a decrease in systemic antioxidants with increased lipid peroxidation. The results of this study suggest that dietary PAH exposure significantly affects gene expression and alters the signaling of biological pathways critical in cholesterol biosynthesis and disruptions in systemic oxidative homeostasis.