欧拉型藏羊高原适应性状的进化基因组学研究

More than half of China's grassland located on Qinghai-Tibet plateau, however it had been lacking fine mutton sheep breed which could adapt to the alpine environment for long times. To shorten the modern Tibetan sheep breeding process, the urgent need to identify genes associated with traits of alpine environment adaption as molecular breeding markers. But so far, only two sheep plateau adaptive genes have been reported, all of which were involved in our group. We plan to perform genomics and population genetic analysis using the re-sequencing data of Oula sheep and its related Tibetan breeds, Ganjia sheep and Minxian black sheep and identify their artificial selection genes by HKA, ROH, Fst test. We will combine the collected re-sequencing data from more than 44 sheep breeds, and compare the above data to find the key mutations and expression changes just in artificial selection regions in Tibetan sheep. In addition, this project will also use the wild argali re-sequencing data to detect if the introgression genes from argali to Oula sheep had been under artificial selection. Finally by analyzing the above selected genes via literature mining and genotype and expression verification in a larger sample of experiments, we will find the candidate genes associated with high-altitude adaptation. This study will lay a foundation for molecular breeding of specialized Tibetan meet sheep breed.

我国一半以上的草场在青藏高原牧区，却一直缺乏适应高寒缺氧环境的高产肉羊品种。为缩短藏羊的现代化育种进程，亟需鉴定藏羊的高原适应性状关联基因作为分子选育标记。但到目前为止，仅有本课题组参与的两个绵羊高原适应性基因被报道。本课题拟以地方良种欧拉型藏系绵羊为重点研究对象，在种内和近缘种间两个尺度进行基因组和转录组水平的群体遗传学分析。首先，获得欧拉羊及藏系高原型甘加羊和山谷型岷县黑裘皮羊的重测序数据，与已经收集到的44个世界绵羊品种的基因组数据进行比较，利用HKA、ROH和Fst等进化检验方法筛选藏羊共有的受人工选择基因；其次，利用本课题组前期测序的青藏高原野盘羊的基因组数据，检测出欧拉羊基因组中源自盘羊的渗入基因；最后，对上述两类鉴定基因进行高原适应性相关功能的文献挖掘，并进行大样本的基因型和表达量实验验证，以获得可信的高原适应性候选基因，为高原专门化肉羊品种的分子选育提供理论依据。