Population variation reveals independent selection towards small body size in Chinese Debao pony

Body size, one of the most important quantitative traits under evolutionary scrutiny, varies considerably among species and among populations within species. Revealing the genetic basis underlying this variation is very important, particularly in humans where there is a close relationship with diseases and in domestic animals as the selective patterns are associated with improvements in production traits. The Debao pony is a horse breed with small body size that is unique to China; however, it is unknown whether the size-related candidate genes identified in Western breeds also account for the small body size of the Debao pony. Here, we compared individual horses from the Debao population with other two Chinese horse populations using SNPs identified with the Equine SNP 65 Bead Chip. The previously reported size-related candidate gene HMGA2 showed a significant signature for selection, consistent with its role observed in human populations. More interestingly, we found a candidate gene ...体型是进化研究中备受关注的重要数量性状之一，在不同物种以及同一物种内的不同种群间均存在显著差异。揭示这种体型差异背后的遗传基础具有重要意义，尤其在与疾病密切相关的人类中，以及在选择模式与生产性状改良息息相关的家养动物中。德保矮马（Debao pony）是中国特有的小型马品种，但目前尚不清楚在西方马品种中已鉴定的体型相关候选基因是否同样是德保矮马体型偏小的成因。本研究借助马SNP 65基因分型芯片（Equine SNP 65 Bead Chip）所鉴定得到的单核苷酸多态性（Single Nucleotide Polymorphism，SNP），对德保马种群个体与另外两个中国马种群展开了对比分析。此前已报道的体型相关候选基因HMGA2呈现出显著的选择信号，这与其在人类群体中所观测到的功能一致。更为有趣的是，本研究发现了一个候选基因……