Integrated lipidomics and transcriptomics analysis reveal lipid metabolism disturbance in scallop (Chlamys farreri) exposure to benzo[a]pyrene

Benzo[a]pyrene (B[a]P) commonly bioaccumulates in lipid-rich tissues due to its lipophilicity and further affects lipid metabolism. The present study systematically investigated the lipid metabolism disturbance in digestive glands of scallops (Chlamys farreri) exposure to B[a]P, based on lipidomics, transcriptomics, molecular and biochemical analysis. We exposed the scallops to environmentally relevant concentrations of B[a]P for 21 days. The bioaccumulation of B[a]P, lipid content and lipid peroxidation in digestive glands were measured. Integrated lipidomics and transcriptomics analysis, the differential lipid species were identified and key genes based on the pathways in which genes and lipid species involved together were selected in scallop exposure to 10 μg/L B[a]P. The changes of lipid profile showed that triglycerides (TGs) were accumulated after 21 days exposure, while the phospholipids (PLs) decreased demonstrated membrane structures were disrupted by B[a]P. In combination with the change of gene expression, we speculated that B[a]P could induce lipids accumulation by up-regulating lipid synthesis-related genes expression, down-regulating lipolysis-related genes expression and interfering with lipid transport. Overall, this study provides new insights into the mechanisms of lipid metabolism disturbance in bivalves exposed to PAHs, and establishes a foundation for understanding the bioaccumulation mechanism of B[a]P in aquatic organisms, which is of great importance for further ecotoxicological study.