略阳乌鸡肤色变异与FM突变的关联性分析

Association Analysis of Variants in Lueyang Black-bone Chicken Skin Color and FM Mutation

20号染色体上2个基因组片段(Dup1和Dup2)的异常复制是引起乌鸡超黑素化性状的关键突变。本研究分析了Dup1、Dup2拷贝数与略阳乌鸡肤色性状的关联性,旨在阐明依据拷贝数对肤色性状提纯的可行性。30只略阳乌鸡和30只尼克鸡Dup1、Dup2拷贝数与胸、背和腿部肤色被测定。肤色性状用Hunter Lab色差仪测定,L值用于评价肤色乌黑程度;拷贝数用Real-time PCR检测。略阳乌鸡3个部位L值均显著低于尼克鸡(P<0.05),变异程度高于尼克鸡;同一品种不同部位间L值差异不显著(P>0.05);L值与Dup1(r=-0.135,P=0.478)、Dup2(r=0.098,P=0.607)拷贝数均不存在相关。研究表明略阳乌鸡L值测定结果与肤色视觉观察结果相一致,可以用作定量评价肤色乌黑程度的指标;FM突变在略阳乌鸡群体中存在,但无法用于肤色性状标记辅助选择。

Hypermelanization is caused by abnormal duplication of two genomic fragments at chromosome 20 which was usually denominated as FM mutation. To explore whether the FM mutation can be used as a marker in purification of skin color of Lueyang black-bone chicken(LYC),relationships of skin color and copy number of Dup1 and Dup2 were analyzed in this study. A total of 30 LYC and 30 Nick chickens(NC)were used to verify the possibility.Skin colors in breast,dorsa and thigh of LYC and NC were measured using Hunter Lab spectrophotometer. L values were measured quantitatively to evaluate gray degree of skin color. Copy number of Dup1 and Dup2 were detected using Real-time PCR. L values of LYC at breast,dorsal and thigh skin were significantly lower than that of NC(P<0.05).Variation of L values in the LYC was higher than that in the NC. L values in LYC and NC had no significant difference among three positions(P>0.05). L values showed a significant relationship neither with Dup1(r=- 0.135,P=0.478)nor with Dup2(r=0.098,P=0.607)in the LYC and NC. The results indicated that L value,which corresponded well to LYC skin color observed,could be used as an indicator quantitatively to evaluate gray degree of skin color. FM mutation exists in LYC. However,it is not an efficient way to purify LYC skin color according to copy number of two duplication fragments.