Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
Yunnan Academy of Grassland and Animal Science, Kunming, Yunnan, China.
J Anim Sci. 2020 Mar 1;98(3). doi: 10.1093/jas/skaa068.
Body size plays a key role in production, health, selection, and environmental adaptation of animals, but the genetic basis of body size variation is not clearly understood. Here, we conducted genome-wide association studies (GWAS) of 15 body size traits using autosomal single nucleotide polymorphisms (SNPs) derived from whole-genome sequences of 31 Brahman cattle and 131 Yunling cattle and identified 20 significant loci, which implicated 18 candidate genes. For ischium width, the most significant SNP was assigned to LCORL, a famous gene controlling body size. For chest width, the most significant SNP was located upstream of BMP5, a secreted ligand of transformation growth factor-beta superfamily of proteins involved in bone and cartilage development. Subsequently, we detected selective sweeps in Brahman cattle using integrated Haplotype Score, composite likelihood ratio, and nucleotide diversity. The results showed CNTNAP5 locus associated with hip cross height and LIMCH1 locus associated with forehead size were in selective signals, which were consistent with higher hip cross height and higher forehead size in Brahman cattle compared with Yunling cattle. Our findings provide genetic insights into variation and selection of body size using GWAS and selective signals and will accelerate future efforts aimed at cattle improvement.
体尺在动物的生产、健康、选择和环境适应中起着关键作用，但体尺变异的遗传基础尚不清楚。在这里，我们使用源自 31 头婆罗门牛和 131 头云南黄牛全基因组序列的常染色体单核苷酸多态性（SNP），对 15 个体尺性状进行了全基因组关联研究（GWAS），鉴定出 20 个显著位点，涉及 18 个候选基因。对于坐骨宽度，最显著的 SNP 被分配给 LCORL，这是一个控制体尺的著名基因。对于胸宽，最显著的 SNP 位于 BMP5 的上游，BMP5 是转化生长因子-β超家族蛋白的一种分泌配体，参与骨骼和软骨发育。随后，我们使用整合的单倍型评分、综合似然比和核苷酸多样性在婆罗门牛中检测到选择信号。结果表明，与臀部交叉高度相关的 CNTNAP5 位点和与额头大小相关的 LIMCH1 位点存在选择信号，这与婆罗门牛的臀部交叉高度和额头尺寸高于云南黄牛一致。我们的研究结果为使用 GWAS 和选择信号研究体尺的变异和选择提供了遗传见解，并将加速未来旨在改良牛的努力。
