Identification of A Novel CYP4V Gene In The Polychaete Perinereis Aibuhitensis: Transcriptional Comparison With CYP4B Exposed To PAHs

Polychaete worms can biotransform polycyclic aromatic hydrocarbons (PAHs) in environments, and the cytochrome P450 (CYP) enzyme plays an important role in this process. Herein, a novel cytochrome P450 gene was identified and characterized from the polychaete worm Perinereis aibuhitensis. The full-length cDNA, which is named CYP4V82, is 1709 bp encoding a protein of 509 amino acids and has high similarity to CYP4V. The expression levels of CYP4V82 and CYP4BB4 (a CYP gene identified from P. aibuhitensis in a previous study, Chen et al., 2012) exposure to various concentrations of benzo[α]pyrene (B[α]P) (0.5, 2, 4, and 8 μg/L) and same mass concentrations of fluoranthene (Flu, 3.2 μg/L), phenanthrene (Phe, 2.9 μg/L), B[α]P (4.0 μg/L) were detected to identify the function of the CYP4 family in P. aibuhitensis. Compared with CYP4BB4, CYP4V82 mRNA was minimally expressed on day 7 but highly sensitive on day 14. Notably, the expression level of CYP4V82 and CYP4BB4 was relatively different in response to PAHs with different benzene rings of the same concentration. The expression of CYP4V82 in the B(a)P group was the highest, while that of CYP4BB4 in the Phe group was relatively higher than the two other groups. These findings suggest that PAHs are associated with the induction of CYP4V82 and CYP4BB4 expressions, which may have different efficiencies in the detoxification of PAHs.

A novel CYP450 gene (CYP4V18) of the shrimp Penaeus schmitti Burkenroad, 1936 (Decapoda, Dendrobranchiata): cloning and down-regulation of CYP4V18 expression by the imidazole derivative KK-42

The CYP4 family is the most ancient and diversified group of P450 and some members are associated with ecdysteroid metabolism in arthropods. In an attempt to research the possible molecular mechanism of KK-42 action on Penaeus schmitti Burkenroad, 1936, one CYP4 cDNA sequence from the hepatopancreas was first cloned and its spatiotemporal expressions were analysed using real-time PCR, and the haemolymph 20-hydroxyecdysone (20E) level was measured by reverse-phase high-performance liquid chromatography. Results showed that the full-length cDNA contains a 1545 bp open reading frame encoding a predicted protein of 515 amino acids named CYP4V18 by the P450 nomenclature committee. The highest cyp4v18 mRNA level was detected in hepatopancreas. Compared with that of the KK-42 treatment group, the hepatopancreas cyp4v18 expression in the control group increased to >72.3%, even 187.7% () on day 6. The haemolymph 20E levels increased slightly in KK-42-treated shrimps compared to that in controls during the experimental stage. The results show that the hepatopancreas CYP4V18 is not involved in 20E biosynthesis, and likely plays other roles in the shrimp, P. schmitti.