Department of Animal Science, School of Agriculture, Tokai University, Kumamoto, Japan.
Kumamoto Station, National Livestock Breeding Center, Kumamoto, Japan.
Anim Sci J. 2020 Jan-Dec;91(1):e13367. doi: 10.1111/asj.13367.
Coat color is one of the important factors characterizing breeds for domestic animals. Melanocortin 1 receptor (MC1R) is a representative responsible gene for this phenotype. Two single-nucleotide polymorphisms (SNPs) in bovine MC1R gene, c.296T > C and c.310G>-, have been well characterized, but these SNPs are not enough to explain cattle coat color. As far as we know, MC1R genotypes of Kumamoto sub-breed of Japanese Brown cattle have not been analyzed. In the current study, genotyping for c.296T > C and c.310G>- was performed to elucidate the role of MC1R in determining the coat color of this sub-breed. As a result, most animals were e/e genotype, suggesting the coat color of this sub-breed is derived from the e allele of MC1R gene. However, we found six animals with E/e genotype, which coat color would be black theoretically. Subsequently, sequence comparison was performed with these animals to identify other polymorphisms affecting coat color, elucidating that these animals possessed the A allele of c.871G > A commonly. c.871G > A was a non-synonymous mutation in the seventh transmembrane domain, suggesting alteration of the function and/or the structure of MC1R protein. Our data indicated that the A allele of c.871G > A might be a loss-of-function mutation.
毛色是家畜品种特征的重要因素之一。黑素皮质素 1 受体（MC1R）是该表型的代表性相关基因。牛 MC1R 基因中的两个单核苷酸多态性（SNP），c.296T>C 和 c.310G>，已经得到了很好的描述，但这些 SNP 不足以解释牛的毛色。据我们所知，尚未分析日本熊本牛的 Kumamoto 亚种的 MC1R 基因型。在本研究中，对 c.296T>C 和 c.310G>进行了基因分型，以阐明 MC1R 在决定该亚种毛色中的作用。结果，大多数动物为 e/e 基因型，表明该亚种的毛色来自 MC1R 基因的 e 等位基因。然而，我们发现了 6 只具有 E/e 基因型的动物，理论上它们的毛色应该是黑色的。随后，对这些动物进行了序列比较，以确定影响毛色的其他多态性，结果表明这些动物携带 c.871G>A 的 A 等位基因。c.871G>A 是第七跨膜域的非同义突变，提示 MC1R 蛋白的功能和/或结构发生改变。我们的数据表明，c.871G>A 的 A 等位基因可能是一个功能丧失突变。
