背景:阐明表型多样性的遗传变异将有助于提高家畜物种的生产性能。中国的藏羊品种具有重要的历史意义,作为青海畜牧业的基本支柱。高原型藏羊,占全省90%的人口,其特点是身材高大,是藏羊的主要品种。相比之下,扎什家羊具有较大的体型和优良的肉质。这两个物种为阐明体型变异的遗传基础提供了极好的模型。因此,本研究旨在对这两个藏绵羊品种进行全面的全基因组关联研究,以鉴定影响藏绵羊体型性状的单核苷酸多态性位点和调控基因。
结果:在这项研究中,体重的表型特征,身体长度,身体高度,胸围,胸部深度,胸部宽度,腰角宽度,在两个藏绵羊品种中评估了管围:高原型羊和扎什家藏羊。全基因组测序产生了48,215,130个高质量的SNPs用于全基因组关联研究。应用了四种方法,鉴定了623个与体型性状显着相关的SNP。在这项研究中鉴定出的显著相关的单核苷酸多态性位于111个候选基因附近或之内。这些基因在cAMP和Rap1信号通路中表现出富集,显著影响动物生长,和身体大小。具体来说,以下基因相关:ASAP1,CDK6,FRYL,NAV2,PTPRM,GPC6,PTPRG,KANK1、NTRK2和ADCY8。
结论:通过全基因组关联研究,我们确定了16个SNPs和10个候选基因与藏羊体型性状相关,具有应用于绵羊基因组选择育种计划的潜力。鉴定这些候选基因将为在绵羊育种中应用分子标记辅助选择奠定坚实的基础,并提高我们对养殖动物体型控制的理解。
BACKGROUND: Elucidating the genetic variation underlying phenotypic diversity will facilitate improving production performance in livestock species. The Tibetan sheep breed in
China holds significant historical importance, serving as a fundamental pillar of Qinghai\'s animal husbandry sector. The Plateau-type Tibetan sheep, comprising 90% of the province\'s population, are characterized by their tall stature and serve as the primary breed among Tibetan sheep. In contrast, Zhashijia sheep exhibit larger size and superior meat quality. These two species provide an excellent model for elucidating the genetic basis of body size variation. Therefore, this study aims to conduct a comprehensive genome-wide association study on these two Tibetan sheep breeds to identify single nucleotide polymorphism loci and regulatory genes that influence body size traits in Tibetan sheep.
RESULTS: In this study, the phenotypic traits of body weight, body length, body height, chest circumference, chest depth, chest width, waist angle width, and pipe circumference were evaluated in two Tibetan sheep breeds: Plateau-type sheep and Zhashijia Tibetan sheep. Whole genome sequencing generated 48,215,130 high-quality SNPs for genome-wide association study. Four methods were applied and identified 623 SNPs significantly associated with body size traits. The significantly associated single nucleotide polymorphisms identified in this study are located near or within 111 candidate genes. These genes exhibit enrichment in the cAMP and Rap1 signaling pathways, significantly affecting animal growth, and body size. Specifically, the following genes were associated: ASAP1, CDK6, FRYL, NAV2, PTPRM, GPC6, PTPRG, KANK1, NTRK2 and ADCY8.
CONCLUSIONS: By genome-wide association study, we identified 16 SNPs and 10 candidate genes associated with body size traits in Tibetan sheep, which hold potential for application in genomic selection breeding programs in sheep. Identifying these candidate genes will establish a solid foundation for applying molecular marker-assisted selection in sheep breeding and improve our understanding of body size control in farmed animals.