Induction of Cytochrome P4501 Genes by Various Inducers in Rainbow Trout (Oncorhynchus mykiss)

Abstract

Gao, K.; Tian, J.; Wu, Y.; Mei, P.; Zhang, Z.; Jonsson, M., and Brandt, I., 2021. Induction of cytochrome P4501 genes by various inducers in rainbow trout (Oncorhynchus mykiss). Journal of Coastal Research, 37(1), 143–148. Coconut Creek (Florida), ISSN 0749-0208.Juvenile rainbow trout is widely found in various aquatic systems, such as freshwater, coastal, and marine habitats all over the world. Expression patterns of the cytochrome P4501 (CYP1) genes exposed to various stressors in such fish could be informative and useful in biomonitoring. In the present study, the induction of CYP1 in rainbow trout by indigo, humic acid (HA), and benzo(a)pyrene (BaP) was studied through a 12-hour exposure experiment by using rainbow trout as an experimental object. First, 7-ethoxyresorufin O-deethylase (EROD) activity and CYP1 expression levels in fish exposed to different concentrations of indigo were analyzed. The EROD activities in fish gills were greatly affected by the concentration of indigo (1, 18, 50, and 80 nM). The expression level of CYP1A1 and CYP1A3 in gills was higher compared with CYP1B1 and CYP1Cs. Second, the gill EROD activity and CYP1 mRNA expressions levels were compared when induced by indigo, HA, and BaP at the same concentration (1 nM). Results indicated that rainbow trout were sensitive to all three inducers. Among them, the HA affected CYP1A1 and CYP1A3 most obviously. CYP1A, as an important biomarker, was more sensitive than CYP1B and CYP1C to those inducers. The observed effects of the different CYP1 inducers could provide a useful tool for monitoring of AhR-active pollutants in the aquatic environment.