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2004 Fiscal Year Final Research Report Summary

Molecular mechanisms of germ cell differntiation before and during meiosis

Research Project

Project/Area Number 14540621
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 生物形態・構造
Research InstitutionFisheries Research Agency (2004)
Okazaki National Research Institutes (2002-2003)

Principal Investigator

KOBAYASHI Tohru  Fishery Research Agency, National Research Institute of Aquaculture, Senior Research Scientist, 養殖研究所・生産技術部, 主任研究官 (30221972)

Project Period (FY) 2002 – 2004
KeywordsSpermatogenesis / Meiosis / Cyclin A / Dmc1 / Cyclin B3 / Cyclin E2 / Spermatogonia / in vitro
Research Abstract

To clarify the molecular mechanisms involved in germ cell differentiation during gametogenesis, the genes involved in controlling these specialized mitotic and meiotic cell cycles of germ cell differentiation must be identified and characterized. The eel testis provides powerful experimental models for investigating the regulatory mechanisms of spermatogenesis, because this model is completely regulated by hormonal induction. To understand the control mechanisms of spermatogenesis, we isolated several kinds of cell-cycle related gene cDNAs, and investigated the relationships between cell cycle-related gene products and gametogenesis in eel testes. After the hormonal induction of spermatogenesis, cyclin E2, A2, and B (B1, B2, B3) are expressed in spermatogonia sequentially. Dmc1 and cyclin A1 become expressed in spermatogenic cells sequentially during meiosis. Although Bl and B2 are expressed in spermatogenic cells from spermatogonia to spermatcytes, cyclin B3 expression is limited duri … More ng spermatogenesis to spermatogonia. The differences in the expression patterns and MPF activities among the B-type cyclins during spermatogenesis after hormonal initiation suggests that each B-type cyclin plays a distinct role in eel spermatogenesis, and that cyclin B3 is specifically involved in spermatogonial proliferation (mitosis), but not meiosis. To clarify the role of E-type cyclins during die initiation of spermatogenesis, we examined the effects of E-type cyclins on spermatogenesis in vitro by introducing E-type cyclins by means of electroporation into testis fragments before the induction of spermatogenesis. The introduction of E-type cyclins in this manner resulted in the initiation of spermatogenesis in vitro, without the need for hormonal induction of spermatogenesis. The initiation of spermatogenesis was accompanied by massive proliferation of type B spermatogonia. but not by self-renewal proliferation of type A spermatogonia, suggesting that an increase in cyclin E2 expression after the hormonal induction of spermatogenesis plays an important role in the shift of spermatogenic cell differentiation from stem cell renewal to active spermatogenesis. Less

  • Research Products

    (10 results)

All 2005 2004 2003 2002

All Journal Article (10 results)

  • [Journal Article] Cloning of cDNAs and their differential expression of A-type cyclins and Dmc1 during spermatogenesis in the Japanese eel, Anguilla japonica.2005

    • Author(s)
      Kajiura-Kobayashi, H., Kobayashi, T.et al.
    • Journal Title

      Dev.Dyn. 232

      Pages: 1115-1123

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Cloning of cDNAs and the differential expression of A-type cyclins and Dmcl during spermatogenesis in the Japanese eel, a teleost fish.2005

    • Author(s)
      Kajiura-Kobayashi, H., Kobayashi, T., Nagahama, Y.
    • Journal Title

      Dev.Dyn. 232

      Pages: 1115-1123

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] The cloning of cyclin B3 and its expression during hormonally induced spermatogenesis in the telesot, Anguilla japonica.2004

    • Author(s)
      Kajiura-Kobayashi, H., Kobayashi, T.et al.
    • Journal Title

      Biochem.Biophys.Res.Commun. 323

      Pages: 288-292

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] The cloning of cyclin B3 and its gene expression during hormonally induced spermatogenesis in the teleost, Anguillajaponica.2004

    • Author(s)
      Kajiura-Kobayashi, H., Kobayashi, T., Nagahama, Y.
    • Journal Title

      Biochem.Biophys.Res.Commun. 323

      Pages: 288-292

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Isolation, characterization and expression of 11b-hydroxysteroid dehydrogenase type2 DNAs from testes of Japanese eel (A.japonica) and Nile tilapia (O.niloticus)2003

    • Author(s)
      Jiang, J.Q., Kobayashi, T.et al.
    • Journal Title

      J.Mol.Endocrinol. 31

      Pages: 305-315

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Isolation, characterization and expression of 11b-hydroxysteroid dehydrogenase type 2 cDNAs from the testes of Japanese eel (Anguillajaponica) and Nile tilapia (Oreochromis niloticus).2003

    • Author(s)
      Jiang, J.Q., Wang, D, S., Senthilkumaran, B., Kobayashi, T., Kobayashi, H K., Yamaguchi, A., Ge, W., Young G., Nagahama, Y.
    • Journal Title

      J.Mol.Endocrinol. 31

      Pages: 305-315

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] A novel progestogen receptor subtype in the Japanese eel, Anguilla japonica.2002

    • Author(s)
      Ikeuchi, T., Kobayashi, T.et al.
    • Journal Title

      FEBS Lett. 550

      Pages: 77-82

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Two isoforms of vasa homologs in a teleost fish : their differential expression during Germ cell differenentiation.2002

    • Author(s)
      Kobayashi, T. et al.
    • Journal Title

      Mech.Develop. 111

      Pages: 167-171

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] A novel progestogen receptor subtype in the Japanese eel, Angirilla japonica.2002

    • Author(s)
      Ikeuchi., T., Todo, T., Kobayashi, T., Nagahama, Y.
    • Journal Title

      FEBS Lett. 550

      Pages: 77-82

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Two isoforms of vasa homologs in a teleost fish : their differential expression during germ cell differentiation.2002

    • Author(s)
      Kobayashi, T., Kajiura-Kobayashi, H., Nagahama, Y.
    • Journal Title

      Mech.Develop. 111

      Pages: 167-171

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2006-07-11  

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