几种雅罗鱼亚科鱼类基于mtDNA序列的亲缘关系

摘要

To define the genetic relationship among five species ( six geographical populations) , including 39 sam-ples collected from Songhua River( L. waleckii, SHJ) , Dali Lake ( L. waleckii, DL) , Erqis River ( L. idus, GT) ,Sayram Lake (L. baicalebsis, BJ), Suifen River [Tribolodon brandit (Dybowski), TT]and Osorezan Lake (L. haronensis Gun-ther, ZX) , three mtDNA sequences of COI, Cytb and D-loop of the six geographical populations, were separately amplified and sequenced. Based on the alignment using softwares Bioedit7. 0 and Clustalx1. 8, the fragments sized 635 bp ( COI) and 1 095 bp ( Cytb-D-loop) were selected for subsequent analysis of genetic diversity and population structure. The results showed that A+T contents on COI and Cytb-D-loop mtDNA regions of six populations were higher than G+G contents. GT and ZX populations had less genetic diversity than other populations. All six populations especially for ZX population had abundant genetic diversity on the region of Cytb-D-loop. Phylogenetic tree revealed that SHJ and BJ, GT and BJ, and TT and ZX had close relationship, respectively. Genetic differentiations occurred in four populations of BJ, GT, TT and ZX and between the four populations and population L. waleckii. No specific locus could be found to distin-guish SHJ from DL, but some loci were found to distinguish the five species.%为探讨瓦氏雅罗鱼( DL, SHJ)、贝加尔雅罗鱼( BJ)、高体雅罗鱼( GT)、滩头雅罗鱼( TT)和珠星雅罗鱼(ZX)5个物种的亲缘关系,对6个雅罗鱼种群共计39个样本进行PCR扩增得到mtDNA 的COI、Cytb和D-loop 核苷酸序列,然后利用Clustalx1.8、Bioedit7.0等软件对序列进行比对、整合,最后选取长度分别为635 bp( COI)和1095 bp(Cytb-D-loop)的序列利用MEGA5.1、DNAsp5.0、Arlequin3.1等软件进行遗传多样性和遗传结构分析。序列分析结果显示,6个雅罗鱼种群在COI、Cytb和D-loop区段的腺嘌呤( A)+胸腺嘧啶( T)含量均高于鸟嘌呤( G)+胞嘧啶( C)含量；遗传多样性分析显示,高体雅罗鱼和珠星雅罗鱼COI基因的遗传多样性相对较低；6个种群在Cytb-D-loop区域的遗传多样性普遍较高,其中珠星雅罗鱼变异最大。遗传距离和邻接法( NJ)系统进化树分析显示,同属于瓦氏雅罗鱼的DL和SHJ群体亲缘关系最近(遗传距离为0.002和0.005),来自新疆的高体雅罗鱼和贝加尔雅罗鱼的亲缘关系最近(遗传距离为0.072和0.052),滩头雅罗鱼和珠星雅罗鱼的亲缘关系最近(遗传距离为0.045和0.170)；不同种群间遗传分化指数显示,除DL和SHJ 2个瓦氏雅罗鱼地理群体未出现明显的遗传分化外,其他4个种群之间及其与瓦氏雅罗鱼2个地理群体间都存在不同程度的遗传分化；种群特异位点分析未找到能够区分瓦氏雅罗鱼DL和SHJ 2个群体的特异位点,但找到了多个能够区分5个雅罗鱼种的特异位点。