牛黑素皮质素受体1(MC1R)基因与毛色表型的研究

Relationship between the melanocortin receptor 1(MC1R) gene and the coat color phenotype in cattle

牛MC1R基因不仅与毛色有关,而且与牛乳中乳蛋白的含量有关。利用PCR-RFLP和DNA测序技术分析了中国荷斯坦黑白花牛,中国荷斯坦红白花牛,鲁西黄牛和渤海黑牛共4个品种的MC1R基因。共检测出3种等位基因(ED,E+,e)。中国荷斯坦黑白花牛主要是ED和E+等位基因(ED=0.12、E+=0.80);渤海黑牛也主要是ED和E+等位基因(ED=0.52、E+=0.47);中国荷斯坦红白花牛和鲁西黄牛大多为e等位基因(e=0.95)。中国荷斯坦红白花牛和鲁西黄牛还存在E+/e基因型。由此推测ED和E+等位基因导致黑色素合成。另外发现牛MC1R基因编码区725处存在一重要的SNP(单核苷酸多态性)。

The MC1R gene is related to coat color in cattle and to lactoprotein content in milk. Polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing were used to analyze the MC1R of China Holstein Black-white Cattle, China Holstein Red-white Cattle, Luxi Yellow Cattle and Bohai Black Cattle. Three alleles （E^D, E^＋ and e） were identified. Most Chinas true for Bohai Black Cata Holstein Black-white Carrie had Ev and E＋ alleles （E^D= 0.12, E^＋ = 0.80）. The same wtle （E^D= 0.52, E^＋ = 0.47）. On the other hand, most China Holstein Red-white Cattle and Luxi Yellow Cattle had the e allele （e/e = 0.95）. E^＋/e genotype was present in China Holstein Red-white Cattle and Luxi Yellow Cattle. We reasoned that E^D and E^＋ lad to the synthesis of the black pigment. Furthermore, we found an important SNP （Single Nucleotde Polymorphism） at 725 position of the MCIR coding region.