青海欧拉羊(Ovis aries)群体中角发育控制基因RXFP2的选择信号分析  

Selection Signals Analysis of the Horn Development Control Gene RXFP2 in Qinghai Oula Sheep(Ovis aries)Populations

作　　者：张强龙 吴森 阎明毅 韩翠 余忠祥 ZHANG Qianglong;WU Sen;YAN Mingyi;HAN Cui;YU Zhongxiang(Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining,810016;Key Laboratory of Plateau Livestock Genetic Resources Protection and Innovative Utilization of Qinghai Province,Xining,810016;Key Laboratory of Ministry of Agriculture and Rural Affairs for Livestock and Poultry Genetics and Breeding on the Qinghai-Tibet Plateau,Xining,810016)

机构地区：[1]青海大学畜牧兽医科学院,西宁810016 [2]青海省高原家畜遗传资源保护与创新利用重点实验室,西宁810016 [3]农业农村部青藏高原畜禽遗传育种重点实验室,西宁810016

出　　处：《基因组学与应用生物学》2024年第3期442-452,共11页Genomics and Applied Biology

基　　金：青海省重大科技专项(2021-NK-A5);青海省畜牧兽医科学院基本科研业务费自主选题项目(MKY-2019-04);农业生产发展资金-联合育种(羊)(2130122)共同资助。

摘　　要：欧拉羊(Oula sheep)属于藏羊(Tibetan sheep)的一个分支。不同于其他国内外绵羊(Ovis aries)品种,欧拉羊的公母羊皆生有大犄角。这是长期放牧条件下自然选择的结果,但其大犄角不利于现代高效畜牧业生产需求。已有较多研究把绵羊无角性状的主效控制基因定位于绵羊10号染色体上的RXFP2基因,但RXFP2基因在不同绵羊品种中的调控作用仍有差别。为加快青藏高原地区无角绵羊品种培育,本研究对青海有角型、无角型欧拉羊成年母羊各15只进行了10×深度的基因组重测序,采用F_(ST)选择性消除定位角表型主要选择基因,并对欧拉羊RXFP2基因CDS区域及上下50 kbp区域以2000 bp窗口、1000 bp步长进行扫描,对获得的单核苷酸多态性(single nucleotide polymorphism,SNP)进行Tajima′s D、π、FST选择分析。结果发现,欧拉羊RXFP2基因及3′下游区域存在强选择信号。通过对RXFP2基因编码区SNP筛选,挖掘了欧拉羊中4个高质量SNPs,分别是位于RXFP2基因第9、第14外显子的同义突变(g.29458690A>G,g.29446067T>C)和第17外显子的2个非同义突变(g.29439053C>T,g.29439011C>T);突变区域均处于无角、有角欧拉羊RXFP2基因的强选择区域。本研究结果可为无角欧拉羊品种(品系)培育相关分子辅助选择工作提供技术和理论依据,有助于加快无角欧拉羊品种培育的早期选种工作。Oula sheep is one branch of Tibetan sheep,which is different from other domestic and foreign breeds of sheep(Ovis aries).Both male and female sheep are born with large horns,which is the result of natural selection under long-term grazing conditions,but its large horns are not conducive to modern efficient animal husbandry production needs.Many previous studies have mapped the main control gene of sheep hornless trait to RXFP2 gene on sheep chromosome 10,but the regulatory effect of RXFP2 gene in different sheep breeds is still different.In order to speed up the breeding of polled sheep breeds in the Qinghai-Tibet Plateau,15 adult horned ewe and 15 adult hornless ewe Oula sheep(Ovis aries)were detected by genome resequencing,respectively,and F_(ST)was used to selectively eliminate the main selection genes for the angular phenotype.The CDS region and the upper and lower 50 kbp regions of RXFP2 gene of Oula sheep were scanned by 2000 bp window and 1000 bp step.Tajima′s D,π,and F_(ST)selection analysis were performed on the single nucleotide polymorphism(SNP)obtained.The results showed that there were strong selective signals in the RXFP2 gene and its downstream regions in Oula sheep.Four high quality SNP in the RXFP2 gene of Oula sheep were identified by SNP screening,which were synonymous mutations(g.29458690A>G,g.29446067T>C)in exon 9 and exon 14 of RXFP2 gene,and two non-synonymous mutations(g.29439053C>T,g.29439011C>T)in exons 17 of RXFP2 gene.All the mutant regions were in the strong selection region of RXFP2 gene of hornless and horned Oula sheep.The results of this study can provide technical and theoretical basis for molecular assisted selection related to the breeding of hornless Oula sheep breeds(strains),and help speed up the early breeding of hornless Oula sheep breeds.

关 键 词：欧拉羊(Ovis aries) 无角欧拉羊 全基因组选择 分子辅助育种 RXFP2 

分 类 号：S826[农业科学—畜牧学]