title: Identification of two juvenile hormone inducible transcription factors from the silkworm, Bombyx mori.
abstract: Juvenile hormone (JH) regulates many physiological processes in insects. However, the signal cascades in which JH is active have not yet been fully elucidated, particularly in comparison to another major hormone ecdysteroid. Here we identified two JH inducible transcription factors as candidate components of JH signaling pathways in the silkworm, Bombyx mori. DNA microarray analysis showed that expression of two transcription factor genes, E75 and Enhancer of split mβ (E(spl)mβ), was induced by juvenile hormone I (JH I) in NIAS-Bm-aff3 cells. Real time RT-PCR analysis confirmed that expression of four E75 isoforms (E75A, E75B, E75C and E75D) and E(spl)mβ was 3-8 times greater after JH I addition. Addition of the protein synthesis inhibitor cycloheximide did not suppress JH-induced expression of the genes, indicating that they were directly induced by JH. JH-induced expression of E75 and E(spl)mβ was also observed in four other B. mori cell lines and in larval hemocytes of final instar larvae. Notably, E75A expression was induced very strongly in larval hemocytes by topical application of the JH analog fenoxycarb; the level of induced expression was comparable to that produced by feeding larvae with 20-hydroxyecdysone. These results suggest that E75 and E(spl)mβ are general and direct target genes of JH and that the transcription factors encoded by these genes play important roles in JH signaling.
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Ueno
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan; Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Aomori, Japan.
authors.forename: Terunori
authors.initials: T
authors.lastname: Kinjoh
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ito
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Shimura
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Noda
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Imanishi
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Kazuei
authors.initials: K
authors.lastname: Mita
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Aomori, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hiruma
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Shinoda
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. Electronic address: kamimura@affrc.go.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kamimura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D026461:Ecdysteroids / Q000096:biosynthesis; D004441:Ecdysterone / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007605:Juvenile Hormones / Q000378:metabolism*; D007814:Larva / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D026461:Ecdysteroids; D019476:Insect Proteins; D007605:Juvenile Hormones; D014157:Transcription Factors; D004441:Ecdysterone
keywords: E75; Ecdysone; Enhancer of split; Hemocyte; Juvenile hormone; Transcription factor