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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，内源性雌激素的生物合成发生在未分化的XX性腺，而不是XY性腺，在任何形态的两性异形出现之前，内源性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，我们对来自正常和雌激素处理的XY性腺的mRNA进行了减法杂交。我们鉴定了10个受调控的基因产物，其中7个与卵巢分化有关，3个与睾丸分化有关。十个基因产物中有两个在生殖细胞中表达，而其他的在体细胞中表达。用甲基睾酮（MT）或芳香化酶抑制剂（AI）治疗30天后，基因性别控制的雌性罗非鱼发生性别逆转。在第12天（性别分化起始期）和第30天（性别分化完成后），通过改良的差异显示比较对照组的基因表达谱。第12天，共鉴定出16个上调基因和21个下调基因；第30天，共鉴定出14个上调基因和19个下调基因。对这些基因进行克隆和测序，然后进行同源性搜索和基因表达分析。在这项研究中，我们研究了鱼类性别变化的机制。人工智能诱导了竞争从女性到男性的性别变化。相比之下，AI和雌二醇-17b（E2）联合使用没有引起性别变化。这些结果强烈表明，内源性E2在性别变化中起着关键作用。通过体外组织培养，我们成功地在3-4周内将完整的卵巢组织诱导为含精子的成熟睾丸组织。据我们所知，这是脊椎动物首次从卵巢组织到完整睾丸的“体外性别改变”。这种实验诱导这种变化的能力对未来脊椎动物性别决定和性别分化的研究具有重要意义。少