title: Identification and expression patterns of Halloween genes encoding cytochrome P450s involved in ecdysteroid biosynthesis in the cotton bollworm Helicoverpa armigera.
abstract: 20-Hydroxyecdysone (20E) is a key hormone which regulates growth, development and reproduction in insects. Although cytochrome P450 enzymes (P450s) participating in the ecdysteroid biosynthesis of 20E have been characterized in a few model insects, no work has been published on the molecular entity of their orthologs in the cotton bollworm Helicoverpa armigera, a major pest insect in agriculture worldwide. In this study, four cytochrome P450 homologs, namely HarmCYP302A1, HarmCYP306A1, HarmCYP314A1 and HarmCYP315A1 from H. armigera, were identified and evolutional conservation of these Halloween genes were revealed among lepidopteran. Expression analyses showed that HarmCYP302A1 and HarmCYP315A1 were predominantly expressed in larval prothoracic glands, whereas this predominance was not always observed for HarmCYP306A1 and CYP314A1. The expression patterns of Halloween genes indicate that the fat bodies may play an important role in the conversion of ecdysone into 20E in larval-larval molt and in larval-pupal metamorphosis, and raise the possibility that HarmCYP315A1 plays a role in tissue-specific regulation in the steroid biosynthesis in H. armigera. These findings represent the first identification and expression characterization of four steriodogenic P450 genes and provide the groundwork for future functional and evolutionary study of steroid biosynthesis in this agriculturally important pest.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
authors.forename: J
authors.initials: J
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
authors.forename: K
authors.initials: K
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China.
authors.forename: X
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D026461:Ecdysteroids / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D019476:Insect Proteins / Q000235:genetics*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009036:Moths / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D026461:Ecdysteroids; D019476:Insect Proteins; D003577:Cytochrome P-450 Enzyme System
keywords: 
                 Helicoverpa armigera
              ; Cytochrome P450; Ecysteroid; Expression pattern; Halloween genes