title: Nitric oxide synthase during early embryonic development in silkworm Bombyx mori: Gene expression, enzyme activity, and tissue distribution.
abstract: To elucidate the mechanism for embryonic diapause or the breakdown of diapause in Bombyx mori, we biochemically analyzed nitric oxide synthase (NOS) during the embryogenesis of B. mori. The gene expression and enzyme activity of B. mori NOS (BmNOS) were examined in diapause, non-diapause, and HCl-treated diapause eggs. In the case of HCl-treated diapause eggs, the gene expression and enzyme activity of BmNOS were induced by HCl treatment. However, in the case of diapause and non-diapause eggs during embryogenesis, changes in the BmNOS activity and gene expressions did not coincide except 48-60 h after oviposition in diapause eggs. The results imply that changes in BmNOS activity during the embryogenesis of diapause and non-diapause eggs are regulated not only at the level of transcription but also post-transcription. The distribution and localization of BmNOS were also investigated with an immunohistochemical technique using antibodies against the universal NOS; the localization of BmNOS was observed mainly in the cytoplasm of yolk cells in diapause eggs and HCl-treated diapause eggs. These data suggest that BmNOS has an important role in the early embryonic development of the B. mori.
authors.affiliation: Department of Biosciences, College of Humanities and Sciences, Nihon University, Setagaya-ku, Tokyo, 156-8550, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kitta
authors.affiliation: Department of Chemistry, College of Humanities and Sciences, Nihon University, Setagaya-ku, Tokyo, 156-8550, Japan.
authors.forename: Marina
authors.initials: M
authors.lastname: Kuwamoto
authors.affiliation: Department of Biology, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yamahama
authors.affiliation: Department of Biosciences, College of Humanities and Sciences, Nihon University, Setagaya-ku, Tokyo, 156-8550, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Mase
authors.affiliation: Department of Biosciences, College of Humanities and Sciences, Nihon University, Setagaya-ku, Tokyo, 156-8550, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sawada
mesh_terms: D000818:Animals; D012831:Bombyx / Q000196:embryology / Q000201:enzymology*; D047108:Embryonic Development / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D019476:Insect Proteins / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D009928:Organ Specificity / Q000502:physiology
chemical_list: D019476:Insect Proteins; D019001:Nitric Oxide Synthase
keywords: 
  Bombyx mori
  ; HCl treatment; diapause; diapause prevention or breaking; nitric oxide synthase