Anti-Müllerian-hormone and gonadotropin dependent changes in testis and pituitary of a cichlid fish, the Nile tilapia (Oreochromis niloticus).

尼罗罗非鱼是一种非洲慈鱼，与优势和从属动物形成社会等级关系。优势雄性卵泡刺激素(FSH)水平高，精子生成被激活。显性个体可以抑制下级的生殖功能。脊椎动物的精子发生受促性腺激素(如FSH)和雄激素(如睾酮)的控制。抗苗勒氏激素(AMH)是脊椎动物生殖细胞发育和类固醇合成的重要调节因子。AMH在显性罗非鱼和次级罗非鱼的睾丸中的表达存在差异。我们想探索这些荷尔蒙之间的相互关系。我们以罗非鱼为模型鱼，目的是将社会地位的变化与精子发生的内分泌和旁分泌控制联系起来。通过体外睾丸器官培养，研究重组FSH、11-酮睾酮(11-KT)和重组AMH对睾丸发育的影响。表达和细胞学分析将通过定量聚合酶链式反应和免疫组织学检测选定的关键基因，并通过在细胞水平上估计增殖和凋亡来进行。此外，对激素处理的睾丸培养物的转录组分析将被用于鉴定AMH的靶基因，并获得关于FSH和11-KT依赖或独立表达AMH控制基因的信息。已鉴定的处理器官培养的差异表达基因将与来自显性和从属男性的转录组数据进行比较。社会优势伴随着促性腺细胞的增殖。AMH也存在于尼罗罗非鱼脑和脑垂体的性腺外，是调节细胞增殖和发育的有力候选者。因此，我们还打算通过器官型脑片培养来研究AMH对促性腺细胞的影响。AMH也可以通过血流分配，通过AMH特异性酶联免疫吸附试验，我们将测定主导和从属男性的血清水平。该项目的成果将使人们深入了解荷尔蒙控制以及社会地位和社会压力对尼罗罗非鱼性腺发育和繁殖的作用，尼罗罗非鱼是一个重要的经济物种。这一结果还将有助于解开哺乳动物精子发生的复杂内分泌控制。

Nile tilapia is an African cichlid and develops social hierarchies with dominant and subordinate animals. Dominant males have high levels of follicle stimulating hormone (FSH) and spermatogenesis is activated. A dominant individual can suppress the reproductive function of subordinates. Spermatogenesis of vertebrates is controlled by gonadotropins (like FSH) and androgens (like testosterone). The Anti-Müllerian-hormone (AMH) is an important regulator of germ cell development and steroid production in the gonads of vertebrates. AMH is differentially expressed in the testes from dominant and subordinate tilapia males. We want to explore the interrelations of these hormones. We use tilapia as a model fish with the aim to correlate changes in the social status with the endocrine and paracrine control of spermatogenesis. By the use of ex vivo testis-organ cultures we will investigate the influence of recombinant FSH, 11-Ketotestosteron (11-KT) and recombinant AMH on testis development. Expression and cytological analysis will be performed by quantitative PCR and immune-histological detection of selected key genes and by estimation of proliferation and apoptosis at the cellular level. Furthermore, the analysis of the transcriptome of the hormone-treated testis-cultures will be used to identify AMH target genes and to obtain information about FSH and 11-KT dependent or independent expression of AMH controlled genes. The identified differentially expressed genes of the treated organ cultures will be compared with the transcriptome data from dominant and subordinate males.Social dominance is accompanied by a hyperplasia of gonadotropic cells. AMH is also present outside of the gonads in brain and pituitary of Nile tilapia and is a strong candidate for regulation of cell proliferation and development. Therefore, we also intend to investigate the influence of AMH on gonadotropic cells by organotypic brain-slice cultures. AMH can be allocated also via the blood stream and by an AMH specific ELISA we will determine the serum level in dominant and subordinate males. The outcome of this project will give insight into hormonal control and the role of the social status and social stress on gonad development and reproduction in Nile tilapia, which is an economically important species. The results will also help to unravel the complex endocrine control of spermatogenesis in mammals.