Molecular Mechanisms of Sex Change in Fish

鱼类性别变化的分子机制

基本信息

批准号：
16370032
负责人：
NAGAHAMA Yoshitaka
金额：
$ 9.54万
依托单位：
National Institute for Basic Biology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

The gobiid fish, Trimma okinawae, possesses ovarian and testicular tissues simultaneously in its gonad and is able to change sex repeatedly in both directions depending on its social surroundings. As sex change in both directions can be socially manipulated, T.okinawae provides an excellent animal model to investigate molecular mechanisms of sex change. The involvement of gonadotropins in sex change was examined by determining the changes in gonadotropin (FSH and LH) receptor gene (GtHRs) expression in gonads during the onset of sex changes from female to male and male to female. The results were intriguing as the expression of the GtHRs was found to be confined to the active gonad of the corresponding sexual phase. When the sex change was occurring from female to male, initially the ovary had high levels of FSHR and LHR, which eventually went up in the testicular tissue once the fish had realized the fact that it was bigger than the other in the aquarium. Opposite of this scenario was … More observed if another fish bigger than the newly sex-changed male was introduced into this aquarium. Swapping of the gonads started with switching of the GtHR expression that was discernible within 12-24 hrs of the visual cue. Our findings show that the gonads of successive sex changing fish possess the intrinsic mechanism to respond to the social cue differentially. Additionally, this location switching of GtHR expression also could substantiate the importance of hypothalamo-pituitary-gonadotropic axis.The wrasse, Pseudolabrus sieboldi, changes sex from female to male. In this study, to investigate the role of estradio1-17β (E2) and 11-ketotestosterone (11KT) in the conversion between oogenesis and spermatogenesis in the gonad, ovarian and testicular tissues were incubated with E2 or 11-KT respectively using in vitro organ culture system. In the culture of ovarian tissues with 11KT, the cysts of spermatozoa, spermatids, and spermatocytes appeared, while oocytes disappeared. On the contrary, E2 treatment could not organize the cysts of any testicular germ cells in ovarian tissues. In the culture of testicular tissues with 11KT, the cysts of spermatozoa, spermatids, and spermatocytes were observed, while with E2, there was a complete degeneration of testicular tissues. This newly developed organ culture system will provide an excellent in vitro system to study the molecular mechanisms of sex change in fish. Less

Gobiid Fish Trimma Okinawae仅在性腺中就具有卵巢和有证明的组织，并且能够根据其社交环境反复在两个方向上反复改变性行为。由于可以在两个方向上进行性别改变，因此T.Okinawae提供了一种出色的动物模型来研究性别变化的分子机制。通过确定促性腺激素（FSH和LH）受体基因（GTHRS）表达在性腺中，从女性到男性对男性变为女性到女性的性别变化期间，促性腺激素参与性改变。由于发现GTHR的表达仅限于相应性阶段的活性性腺，因此结果很有趣。当性别改变从雌性到男性时，最初卵巢具有高水平的FSHR和LHR，一旦鱼意识到它比水族馆中的另一个大，最终会在有证据的组织中上升。与这种情况相反的是……如果将另一只鱼比新近变化的雄性大的鱼被引入该水族馆。性腺的交换始于在视觉提示的12-24小时内切换的GTHR表达式。我们的发现表明，成功改变性鱼的性腺潜力是对社会提示差异反应的内在机制。此外，GTHR表达的该位置切换还可以证实下丘脑 - 垂体 - 巨型轴轴的重要性。包裹，伪核心sieboldi，改变性别从女性变为男性。在这项研究中，为了研究Estradio1-17β（E2）和11-酮酮（11KT）在性腺中卵子发生和精子发生之间的转化中的作用，使用体外器官培养系统与E2或11-KT一起孵育E2或11-KT。在具有11KT的卵巢组织培养中，出现了精子，精子，精子和精子细胞的囊肿，而卵母细胞则消失。相反，E2治疗无法组织卵巢组织中任何均匀生殖细胞的囊肿。在具有11KT的测试组织培养中，观察到精子，精子和精子细胞的囊肿，而在E2的情况下，观察到了完整的测试组织变性。这种新开发的器官培养系统将为研究鱼类性变化的分子机制提供出色的体外系统。较少的