スギモト マサズミ   Sugimoto Masazumi
  杉本 雅純
   所属   東邦大学  理学部 生物分子科学科
   職種   教授
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Effects of androgens on development of nuptial coloration and chromatophores in bitterling Rhodeus ocellatus ocellatus.
掲載誌名 正式名:Zoological Science
略  称:Zool Sci
ISSNコード:02890003
巻・号・頁 26(2),125-130頁
著者・共著者 Kobayashi M, Tajima C, Sugimoto M.
発行年月 2009/02
概要 Sexually mature male bitterlings, Rhodeus ocellatus ocellatus, exhibit distinct nuptial color, whereas females maintain a body color similar to that of juveniles. In the present study, body color and chromatophores were compared between male and female bitterlings, and the effects of androgens on body color and chromatophore densities were examined in females to clarify the role of androgen in the development of nuptial coloration and chromatophores. Males showed green, blue, and red color in specific regions of their skin and red color on the dorsal and caudal fins; females showed a subdued silver body color. For chromatophores, small greenish-type iridophores were observed in the green color region in the skin of males, whereas females had large spindle-shaped silvery-type iridophores in corresponding regions. Many erythrophores were observed in males in blue and red color regions in the skin and red color regions in the fins, but females possessed xanthophores in corresponding regions. The melanophore density of the skin was not different between males and females, but the distribution of melanophores in the fins was different between them. Treatment with 11-ketotestosterone or methyltestosterone induced male-type nuptial coloration in the female skin and fins. The distribution of chromatophores in androgen-treated females was similar to that in sexually mature males: an increase in the number of greenish-type iridophores and erythrophores was also observed in the skin. These results indicate that androgen induces male-type nuptial coloration in the bitterling and that the responses of chromatophores to androgen differ with the type and distribution site of the chromatophores.