Switching of Reproductive Strategy in planarian

涡虫繁殖策略的转换

• 批准号: 15370097
• 负责人: HOSHI Motonori
• 金额: $ 6.34万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15370097/
• 关键词: reproductive strategy; sexualizing substance; planarian; germ cell; 生殖様式転換; 有性生殖; 無性生殖; ネオブラスト; テロメア; 生殖様式の転換; 有性化物質; 分裂誘導物質の単離・同定; 関連遺伝子群; 新生細胞の単離・培養・移植; 核学的解析

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

各种后生动物可以以多种方式繁殖，并根据环境条件和/或生命周期的阶段选择替代的生殖策略，如无性或有性，以及双亲或单亲。然而，生殖方式选择和转换的机制仍有待探讨。许多淡水涡虫通过横向分裂进行无性繁殖，也通过交配进行有性繁殖。无性生殖的蠕虫不形成任何性器官，而有性生殖的蠕虫具有雌雄同体的性器官，并且不进行分裂。本研究建立了一个实验系统，分析了琉球三角涡虫（Dugesia ryukyuensis）从无性生殖到有性生殖转变的机制。如果将该物种的无性克隆（OH株）的蠕虫用性成熟的褐色蛭头蚤（一种纯性物种）的蠕虫喂养，所有这些蠕虫都会在几周内逐渐发育卵巢，睾丸和其他性器官，然后交配，最终产下充满受精卵的茧。这表明性成熟的蠕虫含有一种假定的性化物质，这种物质不是很有属特异性。完全性化的OH蠕虫（获得性）产生它们自己的性化物质。缺少性化物质的头部碎片再生为无性体，而含有性化物质的其他部分再生为有性体。因此，他们很可能通过产生足够量的性物质来保持性。我们正试图确定后天性行为中的性化物质，到目前为止已经澄清，它是酸性的，热稳定的，小于0.5 kDa的和耐链霉蛋白酶的。核磁共振分析表明L-trp是一种可能的性化物质

项目成果

Asterosap-induced elevation in intracellular pH is indispensable for ARIS-induced sustained increase in intracellular Ca^<2+> and following acrosome reaction in starfish spermatozoa

Asterosap 诱导的细胞内 pH 升高对于 ARIS 诱导的细胞内 Ca^2 持续增加和海星精子顶体反应是必不可少的

• 发表时间: 2005
• 期刊: Zygote 13
• 作者: Osamu Kawase;Hiroyuki Minakata;Motonori Hoshi;Midori Matsumoto
• 通讯作者: Midori Matsumoto

ゲノム情報を超えた生命のふしぎ 糖鎖

超越基因组信息的生命之谜——糖链

• 发表时间: 2003
• 作者: 小林一也;松本緑;星元紀;星 元紀
• 通讯作者: 星 元紀

Guanylyl cyclase and cGMP-specific phosphodiesterase participate in the acrosome reaction of starfish sperm

• DOI: 10.1017/s0967199404002977
• 发表时间: 2004-11-01
• 期刊: ZYGOTE
• 影响因子: 1.7
• 作者: Kawase, O;Ueno, S;Matsumoto, M
• 通讯作者: Matsumoto, M

Change of reproduction strategy : Sexual or Asexual

繁殖策略的改变：有性或无性

• 发表时间: 2003
• 期刊: Biol. Internat 44
• 作者: Sumitaka Hase;Kazuya Kobayashi;Ryo Koyanagi;Motonori Hoshi;Midori Matsumoto;Motonori Hoshi
• 通讯作者: Motonori Hoshi

Sumitaka Hase: "Transcriptional pattern of a novel gene, expressed specifically after the point-of-no-return during sexualization, in planaria"Development Genes & Evolution. 212. 585-592 (2003)

Sumitaka Hase：“一种新基因的转录模式，在涡虫性化过程中的不归路点后特异性表达” 发育基因