基于小尺度高原鼢鼠种群遗传结构研究

摘要

The plateau zokor is a subterranean rodent that is one of the unique native animals living on the Tibetan Plateau.Research on the genetic structure of zokor will be useful to understand its patterns of dispersal and genetic exchange.In this study,we focused on the genetic structure of four plateau zokor populations in the alpine meadow in the eastern Qilian Mountains in northwest China.We used microsatellite marker technology to study the genetic diversity and structure of these populations.The effective alleles (Ne) value was 83.6 in the four different geographic populations.The highest average observed heterozygosity (Ho) value was 0.32,and the expected heterozygosity (He) value was 0.50.The average polymorphism information content (PIC) value was 0.40,indicating that plateau zokor have medium-level genetic diversity.A genetic structure analysis divided the four populations into two groups;one group containing the MYT (Mayingtan) population;and the other group containing XNG (Xianannigou),MYR,and MYL populations (west and east of the Maying river,respectively).The genetic distance (FsT) values were greater than 0.05 and gene flow values were lower than 1 in the four geographical populations.These results indicated that the island-type habitat has limited genetic exchange among plateau zokor populations.Rivers and roads may have restricted the movement and exchange of individuals among and within populations.%高原鼢鼠是青藏高原特有的地下啮齿动物,研究其种群遗传结构对于了解扩散、基因交流等方面具有重要意义.本研究利用微卫星分子标记技术,分析祁连山东段高寒草甸区小尺度下4个高原鼢鼠种群的遗传多样性和遗传结构特点.结果表明:1)4个种群有效等位基因(Ne)为83.6,种群平均观测杂合度(Ho)最高为0.32,平均期望杂合度(He)最高为0.50,平均多态信息含量(PIC)为0.40,遗传多态性处于中等水平.2)种群遗传结构推导分析结果为4个种群被分成2组,MYT(马营滩种群)为一组,XNG(下南泥沟种群)、MYR(马营河东边种群)、MYL(马营河西边种群)为一组.3)试验区高原鼢鼠种群间近交系数(FsT)都大于0.05,种群间的基因流值(Nm)都小于1,特殊岛状栖息地限制了高原鼢鼠种群基因流,河流和公路可能对种群内和种群间个体交流有阻碍作用.