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的慈鲷，并发展出有支配和从属动物的社会等级制度。优势雄性有高水平的促卵泡激素（FSH），精子发生被激活。一个优势个体可以抑制下属的繁殖功能。脊椎动物的精子发生是由促性腺激素（如FSH）和雄激素（如睾酮）控制的。抗<s:1>勒勒激素（AMH）是脊椎动物性腺生殖细胞发育和类固醇生成的重要调节因子。AMH在雄性罗非鱼的睾丸中有差异表达。我们想要探索这些激素之间的相互关系。我们使用罗非鱼作为模型鱼，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，我们将研究重组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PCR和选定关键基因的免疫组织学检测以及细胞水平上的增殖和凋亡估计来进行。此外，对激素处理的睾丸培养物的转录组分析将用于鉴定AMH靶基因，并获得有关FSH和11-KT依赖或独立表达的AMH控制基因的信息。经处理的器官培养物中鉴定的差异表达基因将与显性和从属雄性的转录组数据进行比较。社会支配伴随着促性腺细胞的增生。AMH也存在于尼罗罗非鱼的脑和垂体的性腺外，是调节细胞增殖和发育的有力候选物质。因此，我们也打算通过器官型脑切片培养来研究AMH对促性腺细胞的影响。AMH也可以通过血液分配，通过AMH特异性ELISA，我们将确定优势和从属男性的血清水平。尼罗罗非鱼是一种具有重要经济价值的鱼类，本项目的研究结果将有助于深入了解激素调控以及社会地位和社会压力对其性腺发育和繁殖的影响。该结果也将有助于揭示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.