title: Cloning and characterization of the Bombyx mori ecdysone oxidase.
abstract: The physiological titer of molting hormones in insects depends on relative activities of synthesis and degradation pathways. Ecdysone oxidase (EO) is a key enzyme in the inactivation of ecdysteroid. However, there are only a few reports on ecdysteroid inactivation and its enzymes in silkworm. In this study, we cloned and characterized the Bombyx mori EO (BmEO). The BmEO cDNA contains an ORF of 1,695 bp and the deduced protein sequence contains 564 amino acid residues. The deduced protein sequence contains two functional domains of glucose-methanol-choline oxidoreductase in N-terminal and C-terminal. Comparing the expression levels of BmEO in different tissues, high transcription was mainly present in hemocytes. Reduced expression of this enzyme is expected to lead to pathological accumulation of ecdysone in the hemolymph of silkworm larvae or pupae. Our data show that RNA inference of BmEO transcripts resulted in the accumulation of ecdysteroid and death of larvae or pupae. We infer that EO is a crucial element in the physiology of insect development.
authors.affiliation: Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Hua-Jun
authors.initials: HJ
authors.lastname: Yang
authors.forename: Mei-Xian
authors.initials: MX
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Awquib
authors.initials: A
authors.lastname: Sabhat
authors.forename: Firdose Ahmad
authors.initials: FA
authors.lastname: Malik
authors.forename: Roy
authors.initials: R
authors.lastname: Bhaskar
authors.forename: Fang
authors.initials: F
authors.lastname: Zhou
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Li
authors.forename: Jia-Biao
authors.initials: JB
authors.lastname: Hu
authors.forename: Chun-Guang
authors.initials: CG
authors.lastname: Sun
authors.forename: Yan-Shan
authors.initials: YS
authors.lastname: Niu
authors.forename: Yun-Gen
authors.initials: YG
authors.lastname: Miao
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D026461:Ecdysteroids / Q000378:metabolism*; D006434:Hemocytes / Q000201:enzymology; D006458:Hemolymph; D007814:Larva / Q000201:enzymology / Q000254:growth & development; D011679:Pupa / Q000201:enzymology / Q000254:growth & development; D034622:RNA Interference; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein
chemical_list: D018076:DNA, Complementary; D026461:Ecdysteroids; D015096:3-Hydroxysteroid Dehydrogenases; C020096:ecdysone oxidase