Kijas J M, Wales R, Törnsten A, Chardon P, Moller M, Andersson L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, S-751 24, Uppsala, Sweden.
Genetics. 1998 Nov;150(3):1177-85. doi: 10.1093/genetics/150.3.1177.
The melanocortin receptor 1 (MC1R) plays a central role in regulation of eumelanin (black/brown) and phaeomelanin (red/yellow) synthesis within the mammalian melanocyte and is encoded by the classical Extension (E) coat color locus. Sequence analysis of MC1R from seven porcine breeds revealed a total of four allelic variants corresponding to five different E alleles. The European wild boar possessed a unique MC1R allele that we believe is required for the expression of a wild-type coat color. Two different MC1R alleles were associated with the dominant black color in pigs. MC1R2 was found in European Large Black and Chinese Meishan pigs and exhibited two missense mutations compared with the wild-type sequence. Comparative data strongly suggest that one of these, L99P, may form a constitutively active receptor. MC1R3 was associated with the black color in the Hampshire breed and involved a single missense mutation D121N. This same MC1R variant was also associated with EP, which results in black spots on a white or red background. Two different missense mutations were identified in recessive red (e/e) animals. One of these, A240T, occurs at a highly conserved position, making it a strong candidate for disruption of receptor function.
黑皮质素受体1（MC1R）在哺乳动物黑素细胞内真黑素（黑色/棕色）和褐黑素（红色/黄色）合成的调节中起核心作用，由经典的延伸（E）毛色位点编码。对七个猪品种的MC1R进行序列分析，共发现四个等位基因变体，对应于五个不同的E等位基因。欧洲野猪拥有一个独特的MC1R等位基因，我们认为它是野生型毛色表达所必需的。两种不同的MC1R等位基因与猪的显性黑色有关。MC1R2在欧洲大黑猪和中国梅山猪中被发现，与野生型序列相比有两个错义突变。比较数据强烈表明，其中一个突变L99P可能形成组成型活性受体。MC1R3与汉普夏品种的黑色有关，涉及一个错义突变D121N。相同的MC1R变体也与EP有关，EP会导致白色或红色背景上出现黑斑。在隐性红色（e/e）动物中鉴定出两种不同的错义突变。其中一个突变A240T发生在一个高度保守的位置，使其成为受体功能破坏的有力候选者。
