Ghrelin通过GH/IGF-1轴调控奥尼罗非鱼生长机理研究

养殖鱼类的生长速度是水产工作者最关注的性状之一。通过杂交获得的奥尼罗非鱼因其生长迅速的杂种优势，得到广泛养殖。研究表明Ghrelin可调节鱼类生长和营养代谢。对奥尼罗非鱼Ghrelin的表达特征及调控作用进行深入探讨，将拓展现有对杂种优势成因的认识。本项目针对奥尼罗非鱼肠道关键内分泌基因Ghrelin进行研究，阐明Ghrelin在奥尼罗非鱼及其亲本中的时空表达模式；探讨不同温度和不同营养条件下的奥尼罗非鱼及其亲本Ghrelin的表达变化；通过腹腔注射重组蛋白阐明Ghrelin对GH/IGF-1轴的调节及反馈调节机制；最后，我们将利用转录组手段鉴定Ghrelin通过GH/IGF-1轴激活的下游信号通路。本项目将从Ghrelin表达模式、调控机制和作用新途径进行挖掘，初步探讨奥尼罗非鱼Ghrelin在杂种优势中扮演的角色，为进一步研究杂交鱼优势产生机制提供依据。

Growth is one of the most important concerned appearances by fishery practitioners. By hybridization, the Nile tilapia × blue tilapia were obtained and extensively cultivated due to its fast growth rate heterosis. Previous studies indicated that Ghrelin regulated growth and nutrition metabolism in fishes. Illustration of the expression characteristics and its regulation of Ghrelin in Nile tilapia × blue tilapia would contribute to elucidate the mechanism of growth heterosis in hybrid fishes. The present project will study the intestinal key endocrine genes, Ghrelin. First, the spatiotemporal expression pattern of Ghrelin would be investigated; the expression changes by temperature and nutrition condition would be discussed; we would clarify the regulatory mechanism of GH/IGF-1 axis by Ghrelin and the feedback regulation via recombinant protein injection; finally, the transcriptome study approach would be employed to indicate the downstream signaling pathway activated by Ghrelin through GH/IGF-1 axis. From the Ghrelin expression pattern, regulatory mechanism and new functional pathway levels, the role of Ghrelin in heterosis from Nile tilapia × blue tilapia would be discussed. The project will provide basis for investigation of heterosis in hybrid fish.