title: Molecular characterization of cytochrome P450 CYP6B47 cDNAs and 5'-flanking sequence from Spodoptera litura (Lepidoptera: Noctuidae): its response to lead stress.
abstract: In insects, P450s are responsible for the oxidative metabolism of structurally diverse endogenous and exogenous compounds including plant allelochemicals and insecticides. A novel full-length P450 cDNA, CYP6B47, was cloned from Spodoptera litura (Lepidoptera: Noctuidae). The sequence is 1718 bp in length with an ORF of 1509 bp encoding 503 amino acid residues. The phylogenetic analysis indicated that CYP6B47 belongs to CYP3 clan and second clade of CYP6Bs which contain 11 P450s from Noctuidae. Quantitative real-time PCR showed that CYP6B47 was expressed only in larvae stages and had a high level of transcription in the midgut and fat body. In addition, we cloned a 2141-bp 5'-flanking regions and presented the basal luciferase activities of promoter. We also predicted multiple putative elements for transcription factors binding in the 5'-flanking region. Interestingly, the expression of CYP6B47 significantly increased in the midgut and fat body after lead (Pb) exposure for 5 generations. Larvae tolerance to the alpha-cypermethrin (35% increased in LC(50)) and fenvalerate (52% increased in LC(50)) were improved after pre-exposure to 50 mg/kg Pb. These dates suggested that lead increased tolerance of larvae to insecticides mainly through transcriptional induction of detoxification genes including CYP6B47.
authors.affiliation: State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jialiang
authors.initials: J
authors.lastname: Zhou
authors.forename: Guren
authors.initials: G
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D024506:5' Flanking Region; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005260:Female; D007305:Insecticide Resistance; D007814:Larva / Q000201:enzymology; D007854:Lead / Q000378:metabolism*; D008156:Luciferases; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D018411:Spodoptera / Q000201:enzymology* / Q000235:genetics; D013312:Stress, Physiological
chemical_list: D007854:Lead; D003577:Cytochrome P-450 Enzyme System; D008156:Luciferases