利用MHC B-L基因外显子2分析部分中国地方鸡种的遗传多态性

应用MHC B-L 基因外显子2直接测序的方法，对9个地方鸡品种的遗传多样性进行研究。通过等位基因频率对各群体的遗传参数、群体间的Tajima Nei遗传距离和Maximum Likelihood遗传距离进行计算，并采用邻接法（NJ）和 Fitch Margoliash方法聚类。结果表明，导致9个地方鸡品种群体间遗传分化的主要原因为基因流，分析聚类的结果显示，不同鸡品种的分子系统发生关系与其地理分布和每个品种的育成史较一致。

Analysis of genetic diversity of indigenous chicken breeds using exon 2 of MHC B-L gene

The genetic diversities of nine Chinese indigenous chicken breeds were investigated by sequencing the MHC B-L exon 2. According to allele frequencies of MHC B-L exon 2， genetic parameter and Tajima-Nei genetic distances and Maximum Likelihood genetic distances were calculated for each breed. By the Neighbor-joining and Fitch Margoliash methods， phylogenetic trees were obtained based on two types of genetic distances. The results showed gene flow was the major factor affecting genetic diversities of nine Chinese indigenous chicken breeds. The phylogenetic relationship among different chicken breeds population was in accordance with their localities and breeding history.