狐狸MC1R基因编码区c. 40A>C和c. 41C>T相邻变异研究

Study on Adjacent Variation of c. 40A>C and c. 41C>T of Fox MC1R Gene in Different Populations

为了检测狐狸MC1R基因多态性及其与毛色表型的相关性,本研究采集两个狐属12种毛色共计163只狐狸的皮肤组织样,利用PCR扩增和产物直接测序的方法获得狐狸MC1R基因1 054bp长的核苷酸序列,并进行了SNPs筛查。用PopGen32和SHEsis软件对突变位点进行了群体遗传学分析,用PANTHER软件评估了突变对基因产生的功能影响,用SPSS二元变量相关统计方法分析了多态位点与毛色表型间的相关性。结果表明,狐狸MC1R基因编码区40(c.40A>C)和41位点(c.41C>T)存在2个相邻错义突变,导致其编码的第14位氨基酸发生了变异:当第40位点为A时,氨基酸由苏氨酸(Thr)转变为异亮氨酸(Ile);当第40位点为C时,氨基酸由脯氨酸(Pro)转变为亮氨酸(Leu)。北极狐属狐在41位点基因型全部为TT型,而狐属狐大部分个体均为CC型,不存在TT型,推测该位点可能是区分狐狸属间的一个重要功能位点。PANTHER预测获知第41位点突变导致的氨基酸替换(p.Pro14Leu)对MC1R功能有显著影响。SPSS二元变量相关分析结果表明,41位点多态性与狐狸毛色表型存在显著低度相关性,推测狐狸MC1R基因编码区第41位点可能是参与其毛色形成的一个相对重要功能位点。

In order to detect the relationship between polymorphism of MCIR gene and coat color in fox,a total of 163 skin samples of 12 coat color foxes were collected. The nucleotide sequence （1 054 bp） of fox MC1R gene were obtained by the method of PCR and direct sequencing,and the polymorphism were analyzed. The population genetics were analyzed using PopGen32 and SHEsis softwares. The effect of mutations on the function of MC1R gene was evaluated using PANTHER software. The relationships between the variable sites and coat color were analyzed by the statistical methods of SPSS bivarate correlation analysis. Two adjacent missense mutations （c. 40A〉C and c. 41C〉T） were found in the coding region of fox MCIR gene, which resulted in codon change of p. Thr14Ile or p. Pro14Leu. When 40 site was A,it led to the substitution between threonine （Thr） and isoleucine （Ile）. When 40 site was C,it led to the substitution between proline （Pro） and leucine （Leu）. All the genotypes of two coat color foxes belonging to Alopex were TT. However,the genotypes of most coat color foxes belonging to Vulpes were CC. It was supposed that 41 site was important in distinguishing Alopex and Vulpes. The in silico functional analysis showed that the amino acid substitution at p. Prol4Leu had significant impact on the function of MCIR. The statistical analysis showed the polymorphism of 41 site had significant low correlation with the fox coat color. The results indicate that SNP c. 41C〉T in the coding region of the MC1R gene is probably associated with the coat color in fox.