A (2)

A2）

• 批准号: 10308033
• 负责人: HOSHI Motonori
• 金额: $ 22.08万
• 依托单位: Keio University (2000-2001)Tokyo Institute of Technology (1998-1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10308033/
• 关键词: Planarian; Sexual reproduction; Asexual reproduction

Asexual worms or an exclusively fissiparous strain (the OH strain) of the planarian Dugesia ryukyuensis keep developing hermaphroditic reproductive organs and eventually undergo sexual reproduction instead of asexual reproduction, namely fission, if they are fed with sexually mature worms of an exclusively oviparous planarian, Bdellocephala brunnea, suggesting that the sexually mature worms has a sexualizing substance(s) The fully sexualized worms no longer need the feeding on sexual worms to maintain the sexuality. Here, we demonstrate that the sexualized worms produce enough of their own sexualizing substance similar to that contained in B. brunnea. In case of surgical ablation of the sexualized worms, the fragments with sexual organs regenerate to become sexual, while those without sexual organs, namely head fragments, regenerate to return to the asexual state. The asexual regenerants from the sexualized worms are also fully sexualized by being fed with B. brunnea. Additionally, it was reported that head region in sexually mature worms lacks the putative sexualizing substance necessary fir complete sexualization (Sakurai, 1981). These results suggest that the fragments without sexual organ lack enough of an amount of the putative sexualizing substance and the sexuality is maintained by the sexualizing substance contained in the sexualized worms.

无性蠕虫或完全裂殖的品系如果用完全卵生的涡虫Bdellocephala brunnea的性成熟蠕虫喂养，琉球三角涡虫（OH株）会不断发育雌雄生殖器官，最终进行有性生殖，而不是无性生殖，即分裂，这表明性成熟的蠕虫具有性化物质。完全性化的蠕虫不再需要以性蠕虫为食来维持性。在这里，我们证明了性化的蠕虫产生足够的它们自己的性化物质，类似于B中所含的物质。brunnea。在手术切除有性化蠕虫的情况下，具有性器官的片段再生为有性，而没有性器官的片段，即头部片段，再生为恢复无性状态。来自有性化蠕虫的无性再生体也通过用B喂养而完全有性化。brunnea。此外，据报道，性成熟蠕虫的头部区域缺乏完全性化所必需的假定性化物质（Sakurai，1981）。这些结果表明，没有性器官的片段缺乏足够量的假定的性化物质，并且性化的蠕虫中含有的性化物质维持性。

项目成果

Kobayashi K.et al: "Switching and basic description of sexualizing process. from asexual to sexual reproduction in the planarian Dugesia ryukyuensis: Bioassay system" Zool.Sci. (in press). (1999)

Kobayashi K.等人：“涡虫Dugesia ryukyuensis从无性繁殖到有性繁殖的有性化过程的转换和基本描述：生物测定系统”Zool.Sci。

Motonori Hoshi et al.: "Acrosome reaction In starfish : signal molecules In the jelly coat and their receptors"Zygote. 8. S26-S27 (2000)

Motonori Hoshi 等人：“海星顶体反应：果冻层中的信号分子及其受体”合子。

Tsuyoshi Nakano: "G-Protein βγ Subunit-Dependent Phosphorylation of 62-kDa Protein in the Early Signaling Pathway of Starfish Oocyte Maturation Indeuced by 1-Methyladenine"Developmental Biology. 209. 200-209 (1999)

Tsuyoshi Nakano：“1-甲基腺嘌呤诱导的海星卵母细胞成熟早期信号通路中 62-kDa 蛋白的 G 蛋白 βγ 亚基依赖性磷酸化”发育生物学 209. 200-209 (1999)。

Kobayashi K.et al: "Switching from asexual to sexual reproduction in the planarian Dugesia ryukyuensis." Int.J.Invastebr.Repred.(in press). (1999)

Kobayashi K.等人：“琉球涡虫从无性繁殖转向有性繁殖。”

Matsumoto M.et al: "Sequence analysis of cDNA encoding precursor of Asterosaps" Dev.Geneticv. (in press). (1999)

Matsumoto M.et al：“编码 Asterosaps 前体的 cDNA 的序列分析”Dev.Geneticv。