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Studies of Mecteinism of sex determination and sex diferentiation in fish.

鱼类性别决定和性别分化的机械论研究。

基本信息

批准号：
14360114
负责人：
NAKAMURA Masaru
金额：
$ 9.09万
依托单位：
University of the Ryukyus
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14360114/
关键词：
Sex Differentiation Sex Determination Sex Change Estrogen Gonad invitrosex change Tilapia 芳香化酵素阻害剤

项目摘要

Our studies indicate that endogenous estrogen biosynthesis occurs in undifferentiated XX gonads but not XY gonads before the appearance of any morphological sexual dimorphism, and that endogenous estrogens are required for ovarian differentiation. To identify the down-stream gene products during ovarian and testicular differentiation, we performed subtractive hybridization using mRNA derived from normal and estrogen treated XY gonads. We identified ten regulated gene products, seven of which related to ovarian differentiation and three to testicular differentiation. Two out of the ten gene products were expressed in germ cells, whereas the others were expressed in somatic cells.Sex reversal was induced in genetically sex-controlled female tilapia by a 30 days treatment with methyltestosterone(MT) or aromatase inhibitor(AI). Gene expression profiles were compared with a control group by modified differential display at Day 12 (initiation period of sex differentiation) and Day 30(just af … More ter completion of sex differentiation). At 12,16 up-regulated and 21 down-regulated genes were identified, where at Day 30,14 up-regulated and 19 down-regulated genes were identified. These genes were cloned and sequenced, followed by homology searches and gene expression analysis.In this study, we examined the mechanism of sex change in fish using a protogynous species. AI induced compete a sex change from female to male. In contrast, AI and estradiol-17b(E2) in combination did not bring about the sex change. These results strongly suggest that endogenous E2 has critical role in sex change.Using in vitro tissue culture, we succeeded in inducing restructuring complete ovarian tissue to mature testicular tissue with sperm in 3-4 weeks. To the best of our knowledge, this is the first demonstration of "in vitro sex change" from ovary tissue to a complete testis in vertebrates. This ability to experimentally induce this change has important implication for future research on sex determination and sex differentiation in vertebrates. Less

我们的研究表明，在出现任何形态上的性别二态性之前，内源雌激素生物合成发生在未分化的 XX 性腺中，而不是 XY 性腺中，并且内源雌激素是卵巢分化所必需的。为了鉴定卵巢和睾丸分化过程中的下游基因产物，我们使用来自正常和雌激素处理的 XY 性腺的 mRNA 进行了消减杂交。我们鉴定了十种受调控的基因产物，其中七种与卵巢分化相关，三种与睾丸分化相关。十个基因产物中的两个在生殖细胞中表达，而其他在体细胞中表达。通过用甲基睾酮（MT）或芳香酶抑制剂（AI）处理30天，在基因性别控制的雌性罗非鱼中诱导性逆转。通过第 12 天（性别分化起始期）和第 30 天（性别分化完成后）的改良差异显示，将基因表达谱与对照组进行比较。在第 12,16 个上调基因和 21 个下调基因被鉴定出，而在第 30 天，14 个上调基因和 19 个下调基因被鉴定出。这些基因被克隆和测序，然后进行同源性搜索和基因表达分析。在这项研究中，我们利用原雌性物种研究了鱼类性别变化的机制。人工智能引发了性别从女性到男性的竞争。相比之下，AI和雌二醇-17b(E2)的组合并没有带来性别改变。这些结果强烈表明内源性E2在性别改变中具有关键作用。利用体外组织培养，我们成功地在3-4周内诱导完整的卵巢组织重组为成熟的睾丸组织。据我们所知，这是脊椎动物从卵巢组织到完整睾丸的“体外变性”的首次演示。这种通过实验诱导这种变化的能力对于未来脊椎动物性别决定和性别分化的研究具有重要意义。较少的