基于MHC-DRB部分序列对不同地区中缅树鼩遗传多样性的研究

Genetic Diversity in Tupaia Belangeri from Different Regions Based on the Partial Sequence of MHC-DRB Gene

基于中缅树鼩的主要组织相容性复合体基因,探讨中缅树鼩的遗传多样性.结果显示:中缅树鼩MHC-DRB内含子4基因扩增出的序列大小为168bp,其中河口种群的核苷酸多样性(π)和平均核苷酸变异数(K)最高,海南种群的单倍型多样性(Hd)最大.核苷酸多样性、平均核苷酸变异数最低的是兴义种群,单倍型多样性最低的是勐腊种群.中缅树鼩MHC-DRB外显子2基因的实验结果表明多态位点数最大值和最小值分别是兴义种群(87)、乐业种群(44);核苷酸多样性最大值和最小值是兴义种群(0.086 68)和乐业种群(0.219 86).非同义突变/同义突变(dN/dS)的结果表明总体样本经历了正选择.说明中缅树鼩MHC-DRB基因具有很高的遗传多样性,中缅树鼩的MHC-DRB基因在历史进程中经历了正选择.

In order to investigate the genetic diversity in Tupaia belangeri,major histocompatibility complex（MHC）gene were analysis.The results showed that MHC-DRB intron 4gene sequences were amplified by the size of 168 bp,and Hekou population had the highest nucleotide estuarine population diversity and the average number of nucleotide variation,and Hainan population had the maximum haplotype diversity.The nucleotide diversity and mean nucleotide variation were lowest in Xingyi population,and the lowest in haplotype diversity was Mengla population.Polymorphism loci in MHC-DRB exon 2 gene were maximum and minimum in Xingyi population （87） and Leye population （44）;the maximum value and the minimum value of the diversity of nucleotide were also the population of Xingyi （0.086 68） and Leye population （0.219 86）,respectively.Analysis of dN/dS test suggested that the overall sample had undergone a positive selection.All of the above results showed that the MHCDRB gene had higher genetic diversity in T.belangeri,which undergo positive selection in the course of history.