2005 Fiscal Year Final Research Report Summary
Switching of Reproductive Strategy in planarian
| Project/Area Number |
15370097
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Developmental biology
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| Research Institution | Keio University |
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Principal Investigator |
HOSHI Motonori Keio University, Faculty of Science and Technology, Professor, 理工学部, 教授 (20012411)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Midori Keio University, Faculty of Science and Technology, Associate Professor, 理工学部, 助教授 (00211574)
KOBAYASHI Kazuya Keio University, Faculty of Science and Technology, Assistant Professor, 理工学部, 助手 (50360110)
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| Project Period (FY) |
2003 – 2005
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| Keywords | reproductive strategy / sexualizing substance / planarian / germ cell |
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| Research Abstract |
Various metazoans can reproduce in multiple ways and select an alternative reproductive strategy such as asexual or sexual, and biparental or uniparental depending upon the environmental conditions and/or the phase of life cycle. However, the mechanism underlying the selection and switch of reproductive modes remains to be explored. Many freshwater planarians reproduce asexually by transverse fission as well as sexually by copulation. Asexual worms do not form any sexual organs, while sexual ones have hermaphroditic sexual organs and do not undergo fission. Some populations within the same species switch these reproductive modes seasonally.
We have established an experimental system to analyze the mechanism underlying the switch from asexual to sexual reproduction in the planarian, Dugesia ryukyuensis. If the worms of an exclusively asexual clone (OH strain) of the species are fed with sexually mature worms of Bdellocephala brunnea, an exclusively sexual species, all of them gradually develop ovaries, testes and other sexual organs within a few weeks, and then copulate, and eventually lay cocoons filled with fertilized eggs. This suggests that sexually mature worms contain a putative sexualizing substance(s) that is not very genus-specific. The fully sexualized OH worms (acquired sexuals) produce their own sexualizing substance. The head fragments lacking the sexualizing substance regenerated into asexuals, though the other portions containing the sexualizing substance regenerated into sexuals. Thus, it is most likely that they keep the sexuality by producing enough an amount of the sexualizing substance. We are trying to identify the sexualizing substance in the acquired sexuals, and have so far clarified that it is acidic, heat-stable, smaller than 0.5 kDa and pronase-resistant. NMR analysis showed that L-trp is one of candidate for sexualizing substances
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[Journal Article] A sperm-activating peptide controls a cGMP-signaling pathway in starfish sperm2003
Author(s)
Midori Matsumoto, Johannes Solzin, Annika Helbig, Volker Hagen, Sei-ichi Ueno, Osamu Kawase, Yoshinori Maruyama, Manabu Ogiso, Matthias Godde, Hiroyuki Minakata, U. Benjamin Kaupp, Motonori Hoshi, Ingo Weyand
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Journal Title
Dev. Biol. 260-2
Pages: 314-324
Description
「研究成果報告書概要(和文)」より
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[Journal Article] A sperm-activating peptide controls a cGMP-signaling pathway in starfish sperm2003
Author(s)
Midori Matsumoto, Johannes Solzin, Annika Helbig, Volker Hagen, Sei-ichi Ueno, Osamu Kawase, Yoshinori Maruyama, Manabu Ogiso, Matthias Godde, Hiroyuki Minakata, U.Benjamin Kaupp, Motonori Hoshi, Ingo Weyand
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Journal Title
Dev.Biol. 260-2
Pages: 314-324
Description
「研究成果報告書概要(欧文)」より
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[Book] 蛋白質 核酸 酸素2005
Author(s)
松本緑, 小林一也, 星元紀
Total Pages
830
Publisher
共立出版
Description
「研究成果報告書概要(和文)」より
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[Book] 蛋白質 核酸 酸素2004
Author(s)
小林一也, 松本緑, 星元紀
Total Pages
720
Publisher
共立出版
Description
「研究成果報告書概要(和文)」より
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