不育雌性三倍体鱼Kisspeptin/GPR54信号系统鉴定及其在HPG轴调控作用研究

In fishes, Kisspeptin as the Rfamine peptide, plays key role in regulatory of the hypothalamus-pituitary-gonadal (HPG) axis. Kisspeptin stimulates the release and synthesis of GtH (gonadotropin) via control of GnRH (gonadotropin-release hormone) secretion．The regulation effect of the Kisspeptin/GPR54 system has close relationship with gonadal development in fishes. Because of abnormalities in ovary development, the female sterile triploid fish can not produce mature ova. In the project, molecular identification of Kisspeptin/GPR54 signaling system and the comparative study on regulatory roles in HPG axis of sterile female triploid fish and fertile diploid fish will be systematically carried out, in order to explore the relationship between the sterile mechanism of ovary in triploid fish and the characteristics of Kisspeptin/GPR54 signal systems, further understanding the molecular endocrine mechanism of the sterile triploids as well as providing theoretical evidences.

RF肽家族的Kisspeptin短肽通过刺激下丘脑GnRH的分泌，从而促进脑垂体GtH的合成与释放。Kisspeptin/GPR54信号系统的调节效应对鱼类的性腺发育有着密切关系。不育雌性三倍体鱼的卵巢发育异常以致不能产生成熟卵子。本项目将系统地开展Kisspeptin/GPR54信号系统的分子鉴定及其在不育雌性三倍体鱼和可育二倍体鱼的HPG轴调控作用的比较研究，以期探索不育三倍体鱼卵巢的不育机制与Kisspeptin/GPR54信号系统特性的关系，为进一步了解和丰富三倍体不育的分子内分泌学机制提供理论依据。

该项目通过PCR和RACE 技术获得了获得二倍体红鲫、异源三倍体鲫的kiss1、kiss2、gpr54a和gpr54b基因部分cDNA全长并进行比较；进行同源性分析和构建统进化树，结果显示两种鱼具有极为相近的亲缘关系；采用Real-time PCR的方法比较研究了kiss1、kiss2、gpr54a、gpr54b基因在二倍体红鲫和异源三倍体鲫鱼不同发育时期HPG轴的差异表达情况，采用组织原位杂交的方法，检测了kiss2基因mRNA在在二倍体红鲫和异源三倍体鲫鱼下丘脑和垂体的组织定位情况。研究结果表明不育三倍体雌鱼的Kisspeptin/GPR54信号系统调控HPG生殖轴与可育二倍体红鲫的相比出现了失调，揭示了Kisspeptin/GPR54信号系统在二倍体鱼和三倍体鱼的性激素分泌调节途径中起到关键性作用。该研究为进一步了解和丰富三倍体不育的分子内分泌学机制提供理论依据，在鱼类繁殖生物学和遗传育种方面具有重要意义。该项目发表研究论文5篇，获得了2项授权国家发明专利，合作培养毕业博士研究生1名，硕士研究生2名。