Gene transcription in the oyster Crassostrea gigas exposed to environmental concentrations of the UV filter Benzophenone-3.

Personal care products (PCPs), such as sunscreens, are usually found in various aquatic ecosystems at low concentrations (ng l to µg l). However, there is limited information regarding their effects on marine bivalves. Therefore, the aim of this study was to evaluate the sublethal effects of environmental concentrations (1 and 100 µg l) of benzophenone-3 (BP-3) in Crassostrea gigas oysters after 1 and 7 days of exposure. We analyzed the accumulation of BP-3 in the soft tissue of oysters and the transcription of genes associated with antioxidant enzyme (SOD and CAT), phase I biotransformation (CYP356A1, CYP2AU2 and CYP7A1), phase II biotransformation (GSTO.4A and GSTP.1.1) and nuclear receptors (NR) that regulate gene transcription: CgNR0B, CgNR1P10, CgNR1P11, CgNR2E2 and CgNR5A. The highest accumulation (34.9 ± 5.7 µg g) was observed in oysters exposed for 7 days to 100 µg l. Increased transcription of SOD and CYP356A1 genes was observed in oysters exposed at both concentrations after 1 day of exposure. Additionally, GSTP.1.1 transcription increased after 1 day of exposure to 100 µg l but decreased after 7 days of exposure to 1 µg l. An increase in the transcription of CgNR0B and CgNR1P10 genes was observed in oysters exposed to 100 µg l after 1 day of exposure, while only CgNR5A showed increased transcription after 1 and 7 days of exposure to 100 µg l. Finally, the IBRv2i was significantly higher in the 100 µg l group compared to the control after 1 day of exposure. In conclusion, C. gigas exposed to concentrations that BP-3 could reach in nearshore areas exhibited variations in gene transcription, which could result in imbalances of physiological processes.