黑色素皮质激素受体1基因248位点多态性与中国马品种毛色的相关性分析

在欧洲马品种中,黑色素皮质激素受体1(melanocortin receptor 1,MC1R)基因第248位碱基有C/T多态性,纯合的T248位点决定欧洲马的栗毛色。针对MC1R基因的248位点设计了2对特异性引物,采用等位基因特异性PCR技术,研究3个中国马品种MC1R基因型与栗色毛之间的关系。经扩增获得两种DNA片段,克隆测序后证明,扩增片段确为MC1R基因,两种DNA片段序列在基因的248位点的确呈现C/T多态性,但检测126份贵州矮马、西南马和新疆伊犁马血液样本,全部为杂合基因型(Ee),其中包括栗毛、黑毛、骝毛3种单毛色及3种复毛色。这些研究结果提示,MC1R基因中248位点的多态性与国内3个马品种的栗色毛之间没有直接的相关性。

Association of Polymorphism in MC1R Gene at Site 248 with Chestnut Coat Color in Three Chinese Horse Breeds

A single nucleotide polymorphism (SNP) at site 248 of melanocortin receptor 1 gene (MC1R) is known from European horse breeds, in which the homozygous genotype (ee) is related with the chestnut coat color of European horse individuals. To confirm the polymorphism of site 248 of MC1R gene in Chinese horse, three horse breeds of Guizhou pony, Southwest horse and Ili horse were chosen as samples with coat color of three monochromatic (chestnut, black, bay) and three kinds of complex coat color. Two pairs specific primers were designed. Two fragments, 124 and 481 bp, were amplificated by allele-specific polymerase chain reaction (AS-PCR) method. The polymorphism of site 248 in MC1R gene was further approved by cloning and sequencing of the DNA fragments. The results showed that genotypes of all samples with coat color of chestnut were heterozygous genotype (Ee). However, the genotypes of other samples were Ee either, in which the coat colors included bay, black, grey, spotted but not chestnut. It suggested that the SNP at site 248 of MC1R gene might be unrelated with the chestnut coat color in native Chinese horse breeds.