Molecular cloning of a CYP1A cDNA from the teleost fish Dicentrarchus labrax

A cDNA encoding for cytochrome P450 1A has been cloned in the marine teleos t fish Dicentrarchus labrax. This fish, common in the Mediterranean, was ch osen since it is considered a good sentinel species. Moreover, biomarkers o f exposure to organic contaminants (such as EROD) are often measured in thi s species and make it possible to evaluate the quality of waters. For cloni ng purposes, RNAs were extracted from the liver of benzo[a]pyrene (BaP)-tre ated animals and used as template in degenerate RT-PCR. The cDNA product wa s cloned and used for the design of highly stringent primers that were util ized in Rapid Amplification of cDNA Ends (RACE) PCR. The cloned cDNA hybrid izes with a 2.7 kb mRNA which is induced by treatment of the fish with BaP, a classical CYP1A inducer. The closest sequences found in data banks belon g to fish CYP1A. (C) 1998 Elsevier Science Inc. All rights reserved.