黄颡鱼属两种鱼类的线粒体ND4基因序列变异性分析

MITOCHONDRIAL DNA ND4 GENE SEQUENCES VARIATION OF TWO PELTEOBAGRUS SPECIES

  • 摘要: 以东亚特有种光泽黄颡鱼(Pelteobagrus nitidus)和长须黄颡鱼(Pelteobagrus eupogon)为研究对象,采用PCR技术获得了这两种鱼类的部分线粒体DNA DN4基因及其3′端的tRNA基因碱基共约772个,用MEGA2.1软件分析了此片段序列,采用Kimura双参数模型计算遗传距离,以科属的大鳍(Hemibagrus macropterus)为外类群,用邻接法构建不同水系的光泽黄颡鱼和长须黄颡鱼的分子系统树。不同水系的光泽黄颡鱼的遗传距离在0.000-0.012之间,长须黄颡鱼的遗传距离在0.000-0.003之间,光泽黄颡鱼和长须黄颡鱼种间的遗传距离在0.099-0.108之间,从分子水平上证实了光泽黄颡鱼和长须黄颡鱼为两个有效物种。不同水系的光泽黄颡鱼遗传变异很小,除黑龙江种群外,其他水系的光泽黄颡鱼在分子系统树没有能够按水系区分开来,可能的原因为:(1)不同水系的光泽黄颡鱼之间存在频繁的基因交流;(2)东亚科鱼类的线粒体DNA的进化速率可能较小;(3)人类经济活动可能已影响到光泽黄颡鱼的种群遗传结构。

     

    Abstract: Species of Pelteobagrus nitidus and Pelteobagrus eupogon are endemic to East Asia, which are the specimens in the present study.MtDNA ND4 ( plus three 3c flanking tRNAs: histidine tRNA, serine tRNA and partial leucme tRNA-gene sequence variations of these two species from different drainages were studied in the present study.About 772 base pair sequences were obtained through PCR amplification.Sequence analysis was conducted using MEGA2.1 software.Hemibagrus macropterus was selected as ou-t group.The Kimuraps 2-parameter distances were calculated.The genetic distances among P.nitidus were from 0.000 to 0.012, and the genetic distances among P.eupogon were from 0.000 to 0.003.The genetic distances between P.nitidus from different drainages and P.eupogon were from 0.099 to 0.108, which suggest that P.nitidus and P.eupogon are two valid species.The genetic distances among P.nitidus from different drainages were small, the same as P.nitidus in the same drainages.The possible reasons are the following: ( i-there are frequent gene flow among P.nitidus samples from different drainages: ( ii-the evolution rate of the East Asian bagrid mitochondrial DNA is relatively slow; ( iii-the human economic activ-i ties have probably caused change of genetic population structure of P.nitidus.

     

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