Identification of a CYP3A-like gene and CYPs mRNA expression modulation following exposure to benzo[a]pyrene in the bivalve mollusk Chlamys farreri

• A CYP3A-like mRNA has been isolated from ovary of the scallop (Chlamys farreri).
• High expressions of the CYP3A-like occur in gonad and digestive gland in scallops.
• B[a]P caused CYP3A-like and CYP4 expression to increased in a dose-dependent manner.
• 0.5 and 10 μg/L B[a]P treatments caused significant DNA damage and oxidative damage.

In this study, we isolated a CYP3A-like gene from ovary of the scallop (Chlamys farreri). High levels of CYP3A-like gene expression occur in the digestive gland and gonad, which suggested their role in the metabolism of steroids and xenobiotics. Scallops were exposed to a polycyclic aromatic hydrocarbons (PAHs), benzo[a]pyrene (B[a]P) for 10 days. The CYP4 and CYP3A-like gene can be up-regulated by B[a]P in a dose-dependent manner after 10 days exposure. But no induction of the CYP3A-like was observed in 10 μg/L B[a]P group. The CYP1A-like expression can only be induced by 0.025 μg/L B[a]P. 0.5 and 10 μg/L B[a]P caused significant DNA damage and 10 μg/L B[a]P can also lead to oxidative damage. These results demonstrate that the mollusk CYPs can be modulated by environmental pollutant, and the blocked induction of CYP3A-like and CYP1A-like expression probably results from the high genotoxicity and oxidative damage partly.