塔里木河流域5个地理种群的叶尔羌高原鳅遗传多样性分析

The Analysis of Genetic Diversity of Triplophysa yarkandensis(Day)from Five Geographic Populations in the Tarim River Basin

为研究塔里木河流域叶尔羌高原鳅(Triplophysa yarkandensis)群体的遗传多样性,基于高通量测序平台,对叶尔羌高原鳅基因组进行测序,并筛选出符合条件的微卫星位点,设计100对用于PCR扩增的引物,最终筛选出39对具有多态性的引物,挑选多态性较高的15对在5个河段叶尔羌高原鳅种群中进行扩增,分析不同种群的遗传多样性和种群分化情况。结果显示,5个叶尔羌高原鳅群体的平均等位基因数(Na)和有效等位基因数(N_(e))分别为48.467和15.181,平均观测杂合度(Ho)和期望杂合度(H_(e))分别为0.578和0.929,多态性信息含量(PIC)为0.893,种群间遗传分化系数(Fst)为0.102。其中,车尔臣河群体等位基因数最多(18.143),阿克苏河群体等位基因数最少(10.429);阿克苏河群体的观测杂合度最高(0.706),台特玛湖群体的观测杂合度最低(0.517);阿尔干群体的多态信息含量最高(0.877),阿克苏河群体的多态信息含量最低(0.760);阿克苏河与台南河群体的遗传距离最小(0.606),阿尔干与台南河群体遗传距离最大(1.901);阿尔干群体与台南河群体遗传相似度最低(0.149),阿克苏河与台南河群体的遗传相似度最高(0.545)。群体遗传结构显示,车尔臣河与台特玛湖、阿克苏河与台南河、阿尔干群体分别聚为独立分支。研究表明,塔里木河各个河段叶尔羌高原鳅之间虽然有一定的差异,但仍然有基因交流现象。

To study the genetic diversity of Triplophysa yarkandensis in the Tarim River basin,high-throughput sequencing was used to sequence the genome of T.yarkandensis.We screened for qualified microsatellite loci and designed 100 primers pairs for PCR.A high-throughput sequencing platform was used to randomly sequence the genome of Riplophysa yarkandensis and eligible microsatellite loci were selected to design primers for PCR.Finally,39 primers pairs with polymorphisms were selected.Fifteen pairs were randomly selected to be amplified in the five river populations of T.yarkandensis.The results showed that the average and effective alleles of the five T.yarkandensis populations were 48.467 and 15.181,respectively.The observed heterozygosity(Ho)and expected heterozygosity(H_(e))were 0.578 and 0.929,respectively.The polymorphism information content(PIC)was 0.893.The index of gene differentiation(F_(st))was 0.102.The highest number of alleles was in Che’erchen Lake(18.143),and the lowest number of alleles was in the Akesu River(10.429).The observed heterozygosity of the Akesu River group was the highest(0.706),while the observed heterozygosity of the Taitema Lake group was the lowest(0.517).The polymorphic information content of the Algan population was the highest(0.877),and the polymorphic information content of the Akesu River population was the lowest(0.760).The genetic distance between the Akesu River and Tainan River populations was the smallest(0.606),while the genetic distance between the Algan River and Tainan River populations was the largest(1.901).The genetic similarity between the Algan and Tainan River populations was low(0.149),and the genetic similarity between the Akesu and Tainan River populations was high(0.545).Genetic structuring showed that Che’erchen and Taitema Lakes,Akesu and Tainan Rivers,and the Algan group clustered in one branch.The results of this study show that there are differences among T.yarkandensis populations in the Tarim River,but gene exchange is ongoing.