荷斯坦奶牛红毛性状的基因检测及红毛形成机制的探讨

Genetic Analysis of Red Coat Color Formation in Holstein Cows

荷斯坦奶牛黑素皮质素受体1(MC1R)基因310G缺失突变产生e等位基因,导致红白花毛色。实验利用PCR-RFLP和DNA测序技术建立了荷斯坦奶牛红毛性状的基因检测方法,并在4个荷斯坦奶牛全同胞家系中得到了证实,可见其可用于鉴定携带e等位基因的种公牛,以指导奶牛育种。通过分析黑素皮质素(MC)受体蛋白家族序列,找到了MC1R蛋白结构与功能的区域(TM3、TM6、TM7和EL3)。利用VHMPT软件预测MC1R突变蛋白的结构,结果显示其丢失了TM3、TM6、TM7和EL3区,也失去了与α-促黑素(α-MSH)结合的区域,最终导致红毛的产生。

A G310 deletion of MC1R gene in Holstein Cow creates e allele, leading to red-white coat color. The genetic analysis of red coat color in Holstein Cow was conducted by using PCR-RFLP and DNA sequence technology. This method has been proved effective in four full-sib pedigrees of Holstein Cows and can be used to identify the bull with e allele and to assist dairy cow breeding. By analyzing the amino acid sequences of melanocortin receptor, we found that TM3, TM6, TM7 and EL3 were essential for the structure and function of melanocortin-1 receptor. The structure of mutated melanocortin-1 receptor was predicted by VHMPT program, and it was indicated that mutated Melanocortin-1 Receptor lost its TM3, TM6, TM7 and EL3, as well as the α-MSH binding region. As a result, the red coat color was induced.