3种泥鳅微卫星标记和D-Loop部分序列遗传变异分析

为进一步了解中国当前主要养殖鳅类种质资源现状,实验采用7个微卫星标记和线粒体D-Loop部分序列,对泥鳅(Misgurnus anguillicaudatus,MA)、大鳞副泥鳅(Paramisgurnus dabryanus,PD)和台湾大泥鳅(未见种属分类,TW)3种泥鳅进行群体遗传变异分析.结果显示,6个微卫星位点在3种泥鳅中均能获得有效扩增,1个微卫星标记(Mac239)只在MA中获得特异性扩增,而在PD和TW中未能获得有效扩增条带.在3种泥鳅共90尾个体的D-Loop 部分序列中发现32个单倍型,仅在PD和TW间存在1个共享单倍型.实验中共检测到65个变异位点,其中MA与PD和TW间存在29个特异性位点,而PD和TW间未检测到特异性位点.瓶颈效应和中性检验显示,TW近期可能发生有效群体数量的减少.基于微卫星标记和D-Loop部分序列的遗传变异分析显示,TW和PD间的Nei's遗传距离和K2P遗传距离最近(0.297和0.006),明显小于两者与MA间的遗传距离(1.011～1.899和0.095～0.099);分子方差分析(AMOVA)显示,3种泥鳅的遗传分化极显著(P＜0.01).群体间遗传结构和单倍型网络分析显示,3种泥鳅的遗传结构相对独立,仅在TW和PD间存在一定程度的遗传结构混杂.研究表明,泥鳅和大鳞副泥鳅在遗传结构上存在明显差异,可采用分子标记进行有效鉴别;台湾大泥鳅可能是大鳞副泥鳅的生态种群或遗传改良群体,而非有效物种.

Genetic analysis of three stocks of loach with microsatellite markers and D-Loop partial sequences

In order to increase the understanding of the genetic resources of main economic loach species in China, seven microsatellite markers and mitochondrial D-Loop partial sequences were used to analyse three stocks of loach species, consisting of pond loach(Misgurnus anguillicaudatus, MA), largescale loach(Paramisgurnus dabryanus, PD), and Taiwan large loach(Uncategorized, TW).The results showed that, six microsatellite markers were commonly amplified in three stocks, whereas, one microsatellite marker(Mac239)specifically amplified in MA but failed to obtain effective amplified bands in PD and TW.Thirty-two haplotypes of D-Loop partial sequence detected in ninety individuals from three stocks were analyzed in this study, and there was only one which shared between PD and TW.A total of sixty-five variable sites were detected, twenty-nine of which were specific sites between MA and the others.It would be recently decreased of effective population size in TW, according the bottleneck and neutral test results.Based on the genetic variation analyses using microsatellite markers and D-Loop partial sequence, the closest Nei's genetic distance and K2P distance were found between TW and PD(0.297, and 0.006, respectively), obviously less than the genetic distance between MA and others(1.011-1.899, and 0.095-0.099, respectively);and the analysis of molecular variance(AMOVA)showed that extremely significant genetic differentiation among three stocks were detected in the present study(P<0.01).The results of genetic structure and haplotype network analysis suggested that relative genetic independence was showed among three stocks, whereas, similar genetic resources were only found in TW and PD.In conclusion, the distinct genetic differences in loach species would be effectively identified using molecular markers;and this paper speculated that Taiwan large loach might be the ecology stock or genetic improved population of P.dabryanus, but not effective taxonomy species.