白颈长尾雉微卫星多态性的遗传学分析

Genetic analysis of microsatellite polymorphism in the Elliot’s Pheasant (Syrmaticus ellioti) in China

采用7个微卫星位点遗传标记,对白颈长尾雉(Syrnaticus ellioti)4个地理种群105个个体进行了种群遗传分析。研究发现4个地理种群均偏离Hardy-Weinberg平衡,共检测到62个等位基因,平均等位基因数目为8.86;大多数微卫星位点的观察杂合度值较低,平均为0.504,要明显低于期望杂合度。7个位点的多态信息含量为0.549～0.860,平均为0.712。用无限等位基因模型、逐步突变模型和双相突变模型对4个地理种群的种群瓶颈效应检测,发现各种群近期内都经历过瓶颈效应的影响。地理种群之间的Fst值表明,贵州与湖南地理种群间的分化达到了极显著水平(P<0.001);由Nei氏的无偏遗传距离所构建的邻接树显示,贵州地理种群与湖南地理种群的遗传关系较远。微卫星对不同地理种群的分层分子变异分析(贵州地理种群对其他地理种群)发现:来自地理种群间和组群间的遗传变异量相对较小;而同一地理种群内个体之间的变异量较大(92.84%),且达到显著水平。

In this study, we reported the population genetic analyses in the Elliot’s Pheasant（Syrnaticus ellioti） using seven polymorphism microsatellite loci based on 105 individuals from 4 geographical populations. Departures from Hardy-Weinberg equilibrium were found in four geographical populations. The average number of alleles was 8.86, with a total of 62 alleles across 7 loci; observed heterozygosity （HO） was generally low and the average number was 0.504. For the seven microsatellite loci, the polymorphism information content ranged from 0.549 to 0.860, with an average number 0.712. Population bottlenecks of the four geographical populations were tested by infinite allele mutation model, step-wise mutation model and two-phase mutation model, which found that each population had experienced bottleneck effect during the recent period. Fst analysis across all geographical populations indicated that the genetic differentiaton between the Guizhou geographical population and the Hunan geographical population was highly significant （P0.001）, a finding supported by the far genetic relationship showed by the neighbor-joining tree of four geographical populations based on Nei’s unbiased genetic distances. Using hierarchical analysis of molecular variance （Guizhou geographical population relative to all others pooled）, we found a low level of the genetic variation among geographical populations and that between groups. However, differences among populations relative to the total sample explained most of the genetic variance （92.84%）, which was significant.