CYP1A gene expression in adipose fin of rainbow trout (Oncorhynchus mykiss Walbaum) exposed to benzo[a]pyrene

Abstract

Proximate to the environment, adipose fin of fish may be considered as a lipid storing tissue, and thus can be a target for either waterborne or dietary polycyclic aromatic compounds (PACs). We determined the effects of benzo[a]pyrene (B[a]P), a model PAC member, on CYP1A gene expression in adipose fin and compared that with the effects in gill of juvenile rainbow trout (Oncorhynchus mykiss Walbaum) using the quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). The results of the study demonstrated that constitutive CYP1A mRNA was present in adipose fin of rainbow trout, but the transcripts were far less abundant than those in gill tissue. We confirmed high CYP1A gene induction potential of the gills in rainbow trout injected with benzo[a]pyrene, but also showed moderately and transiently induced CYP1A mRNA in adipose fin. The modest and transitory gene expression may preclude rainbow trout adipose fin CYP1A mRNA levels from using it as an indicator of sustained exposure of fish to the polycyclic aromatic compounds