我国泥鳅微卫星遗传多样性初步分析

用6个微卫星标记分析了安徽(AH)、甘肃(GS)、广东(GD)、广西(GX)、黑龙江(HLJ)、江苏(JS)和重庆(CQ)7个泥鳅(Misgurnus anguillicaudatus)群体的遗传多样性。这6个微卫星摘自泥鳅微卫星连锁图谱,不存在连锁不平衡,在HLJ群体中处于哈代-温伯格平衡,适用遗传多样性分析。六个微卫星共检测到69个等位基因,每位点7到16个不等,有效等位基因数(Ne)3.0-5.5个,观察杂合度在0.202和0.408之间,而期望杂合度在0.673和0.820之间,揭示的多样性信息含量(PIC)在0.643和0.796之间。这些数据显示7个泥鳅群体遗传多样性丰富。群体间遗传分化系数(Fst)达到0.499,49.9%的变异可归于群体间差异,而Fis在0.167和0.421之间,表明泥鳅群体存在较明显的近交或斑块化分布。聚类分析显示AH、GD、HLJ和JS聚成一个分支,而CQ、GS 和GX聚为另一个分支。这表明我国泥鳅呈现东西向梯度分布并在南北向可能存在扰动。这些发现将有助于我国泥鳅资源的有效管理和合理利用。

Preliminary analysis of the microsatellite diversity of Chinese loach (Misgurnus anguillicaudatus)

Six microsatellites were used to describing the genetic diversity of 7 Chinese loach (Misgurnus anguillicaudatus) populations inhabiting Anhui (AH), Gansu (GS), Guangdong (GD) Guangxi (GX), Heilongjiang (HLJ) and Jiangsu (JS) Provinces and Chongqing (CQ) City, respectively. The 6 polymorphic microsatellites were selected from the microsatellite linkage map of loach, being not linked with each other. They were also found to be in Hardy-Weinberg equilibrium in HLJ population, a less disturbed population, thus being suitable for diversity determination. The 6 microsatellites revealed the polymorphism information content (PIC) ranging from 0.643 to 0.796 among populations. In total, 69 alleles were identified, and the number of alleles (Na) varied between 7 and 16, and the effective alleles (Ne) varied between 3.0 and 5.5. The observed heterozygosity (Ho) among populations ranged from 0.202 to 0.408 while the expected heterozygosity (He) ranged from 0.673 to 0.820. These findings indicated that 7 populations were rich in genetic diversity. The co-efficiency of gene differentiation among populations (Fst ) was 0. 499, illustrating that 49.9% of the total variation can be explained by the differentiation among populations. The Fis ranged from 0.167 to 0.421, indicating that serious inbreeding and further uneven distribution exist within populations. The cluster analysis showed that AH, GD, HLJ and JS populations merged into a clade while CQ, GS and GX fused into the other, indicating that the diversity of Chinese loach west-east differentiated and may have been north-south disturbed. Our findings may aid to the management and exploitation of the loach genetic resource of China.