利用细胞色素b（Cyt b）基因分析绿孔雀和蓝孔雀的遗传分化

 采用PCR产物直接测序法测定了10只绿孔雀和5只蓝孔雀的mtDNA细胞色素b基因516 bp序列, 结合已发表的孔雀细胞色素b基因序列数据进行了序列比较分析;以雉鸡和家鸡的同源序列为外群,采用NJ法和ME构建了系统发育树。结果表明蓝孔雀群体内遗传差异程度低于绿孔雀,绿孔雀和蓝孔雀之间的核苷酸差异的平均数为21.417,净遗传距离为0.039±0.01,推断出绿孔雀与蓝孔雀的分化时间至少为2.96百万年,从而在分子水平揭示出绿孔雀和蓝孔雀属于两个不同的物种。重建的系统树将所有序列聚为支持率较高的绿孔雀与蓝孔雀2大类群,显示云南的绿孔雀至少存在两种类型,且这两种类型可能达到了亚种分化水平,而白孔雀和杂色孔雀在分类上则属于蓝孔雀类群。

Genetic Divergence between Pavo muticus and Pavo cristatus by Cyt b Gene

In this paper, 15 DNA sequences spanning 516 bp of the mitochondrial cytochrome b gene (including 10 forPmuticus,and 5 for P cristatus) were determined by using the method of PCR product direct sequencing. Combining with the published cytochrome b gene sequences of peacock in NCBI database together, we conducted sequence analysis to investigate the genetic divergence within the group or between the groups of Pmuticus and Pcristatus, and constructed phylogenetic trees by using the NJ method and ME method with Gallus gallus and Phasianus colchicus as the outgroups. The results revealed that the genetic diversity within Pcristatus was lower than within Pmuticus. Average number of nucleotide differences and net genetic distance between Pmuticus and P cristatus were 21.417 and 0.039±0.01, respectively. The divergence time between P muticus and P cristatus was at least 2.96 Million years based on the substitution rate of nucleotide acid of cytothrome b gene in Galliformes. Our results suggested that P muticus and P cristatus are 2 distinct species. The phylogenetic trees constructed in this study indicated that all the sequences were clustered in 2 major clades (viz. PmuticusandPcristatus) with high bootstrap support values. Further more, our results supported that there are 2 kinds of P muticusin Yunnan Province, China, and they are likely two sub species. Our results still supported that white peafowl and pied peafowl belonged to the species ofP cristatus.