Mx基因抗性位点在12个地方鸡种中的分布及遗传结构分析

The Genetic Distribution and Population Genetic Structure Analysis of Antiviral Resistant Mx Gene Locus in Twelve Chinese Indigenous Chicken Breeds

通过PCR-RFLP技术检测Mx基因S631N位点的抗性等位基因A和敏感性等位基因G在我国地方鸡种中的分布差异。结果表明:PCR-RFLP能准确检测出抗性等位基因A与敏感性等位基因G在12个地方鸡种内的突变,抗性等位基因A在所有群体内的基因频率平均为0.304,敏感性等位基因G的频率平均为0.696;12个地方鸡种群体Mx基因S631N位点的观察杂合度平均为0.657 2,Shannon信息指数平均为0.524 0。在该位点上,12个地方鸡种除仙居鸡显著偏离Hardy-Weinberg平衡(P<0.01)外,其余11个群体均处于Hardy-Weinberg平衡状态(P>0.05);经Ewens-Watterson中立性检验,该位点在各群体内(除白耳鸡群体外)都属于中立性选择。基于该位点等位基因频率构建的UPGMA聚类图将12个地方鸡种分为3大类,聚类结果反映了12个地方鸡种在Mx基因抗性方面存在的差异和优势。

In the experiment,PCR-RFLP technique was used to detect the diffrences of the resistant and sensitive alleles distribution of S631N locus of Mx gene in twelve Chinese indigenous chicken populations.The results showed that the PCR-RFLP technique properly detected the mutation between resistant allele A and sensitive allele G.Among the twelve populations,the average frequencies of resistant allele A and sensitive allele G were 0.304 and 0.696,respectively.The average value of observed heterozygosis and Shannon′s index at this locus were 0.657 2 and 0.524 0,respectively.Except for Xianju chicken,the other eleven populations were all in Hardy-Weinberg equilibrium at this locus（P〉0.05）.Except for Baier chicken,the Ewens-Watterson test indicated that this locus was neutral in all the other populations.The dendrograms based on allele frequency divided the twelve indigenous chicken populations into three clusters,which reflected the difference and advantage of Mx antiviral property in twelve indigenous chicken populations.