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

•BP-3 was accumulated by oysters.•The SOD gene was upregulated, indicating activation of protective processes against BP-3 toxic effects.•The CYP450 356A1 gene was upregulated, suggesting a reduction in BP-3 toxicity.•Nuclear receptor genes were responsive in oysters exposed to BP-3.•The integrated biomarker response (IBRv2i) confirmed the negative impact of BP-3. Personal care products (PCPs), such as sunscreens, are usually found in various aquatic ecosystems at low concentrations (ng L-1 to µg L-1). 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-1) 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-1) was observed in oysters exposed for 7 days to 100 µg L-1. 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-1 but decreased after 7 days of exposure to 1 µg L-1. An increase in the transcription of CgNR0B and CgNR1P10 genes was observed in oysters exposed to 100 µg L-1 after 1 day of exposure, while only CgNR5A showed increased transcription after 1 and 7 days of exposure to 100 µg L-1. Finally, the IBRv2i was significantly higher in the 100 µg L-1 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.