title: Identification of ecdysteroidogenic enzyme genes and their expression during pupal diapause in the cabbage armyworm, Mamestra brassicae.
abstract: In this study, we identified ecdysteroidogenic enzymes in the cabbage armyworm, Mamestra brassicae, and demonstrated reduced expression of these genes during diapause. Some insects employ a temporary developmental arrest, diapause, to survive in severe environments. The titres of the moulting hormone ecdysteroid were reduced in diapause pupae of M. brassicae; therefore, ecdysteroidogenesis might be suppressed by a diapause-specific mechanism. To clarify expression changes of ecdysteroidogenic enzyme genes during diapause in M. brassicae, we first identified the genes for seven ecdysteroidogenic enzymes: Neverland, Non-molting glossy (Nm-g), CYP307A1 (Spook), CYP306A1 (Phantom), CYP302A1 (Disembodied), CYP315A1 (Shadow) and CYP314A1 (Shade). Enzymatic assays using heterologous expression in Drosophila Schneider 2 (S2) cells and analysis of mRNA distribution indicated that the identified genes were ecdysteroidogenic enzymes of M. brassicae. Expression levels of these ecdysteroidogenic enzyme genes were compared between prothoracic glands in different pupal stages throughout diapause. Immediately after pupation, diapause-destined pupae showed similar expression levels of ecdysteroidogenic enzyme genes to those of nondiapause pupae. All of these genes showed reduced gene expression after diapause initiation. Expression was immediately increased in diapause-destined pupae at the postdiapause quiescence phase. These results indicate that reduced expression of ecdysteroidogenic enzyme genes suppresses ecdysteroidogenesis and maintains developmental arrest during diapause.
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: M H
authors.initials: MH
authors.lastname: Ogihara
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yamada
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hikiba
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakaoka
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mizoguchi
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kataoka
mesh_terms: D000818:Animals; D002460:Cell Line; D064666:Diapause, Insect; D026461:Ecdysteroids / Q000096:biosynthesis*; D005260:Female; D015870:Gene Expression; D008297:Male; D009036:Moths / Q000201:enzymology* / Q000235:genetics; D011679:Pupa / Q000201:enzymology
chemical_list: D026461:Ecdysteroids
keywords: M. brassicae; development; diapause; ecdysteroid; ecdysteroidogenesis; endocrinology; gene expression; hormone; prothoracic gland