鲤科25种鱼类线粒体COⅡ基因序列差异及其系统进化关系

Mitochondrial cytochrome oxidase unit II gene variability and phylogenetic relationships among 25 species of Cyprinidae

采用PCR技术获得了23种鲤科鱼类线粒体DNA细胞色素氧化酶（COⅡ）基因部分序列，将所得的COⅡ基因序列与2种取自GenBank的鲤科鱼类同一基因序列采用CLUSTAL X排序后，序列间未见插入和缺失，在实际分析的600bp序列中，共有变异位点250个。以台湾缨口鳅作为外类群，用PAUP4．0软件对序列结果进行统计和分支分析，分别用邻接法和最大似然法构建分子系统树。Kimura双因素模型计算25种鲤科鱼类遗传距离范围为0．0185～0．2375，其中，遗传距离值最小是cān与似鱎（0．0185），最大是似刺鳊鮈与大鳍鱊（0．2375）。分子系统树显示鲤科雅罗鱼亚科、舶亚科、鲤亚科、鮈亚科和鱊亚科均没有各自形成单系群。雅罗鱼亚科被分为北方类群和东亚类群，北方类群是一单系类群，东亚类群与舶亚科、鲴亚科、鲢亚科形成另一个单系群。丁鱥与贝加尔雅罗鱼、东方欧鳊、湖拟鲤等聚成一单系群，支持将丁鱥保留在雅罗鱼亚科中的传统分类法。

Partial sequences of the mitochondrial cytochrome oxidase unit Ⅱ （COv ） gene of 23 species of Cyprinidae amplified by Polymerase Chain Reaction （PCR）, and other two species of Cyprinidae from GenBank were treated by Clustal X and analyzed by PAUP 4.0, while selected outgroup was Crossostoma lacustre. 600 bp gene fragment from these species were obtained, in which 250 variable sites were identified, without insertions or deletions. The two types of molecular phylogenetic trees based on the sequences of 25 species with neighbor-joining method（NJ） and maximum likelihood method（ML）, respectively. The genetic distances among 25 species of Cyprinidae, measured by the kimura-2 parameter model, were from 0.018 5 to 0.237 5. The least genetic distance was 0.018 5 between Hemiculter leucisculus and Toxabramis swinhonis, whereas the largest was 0. 237 5 between Paracanthobrama guichenoti and Acheilognathus macropterus. Leuciscinae, Culterinae, Cypdninae, Gobioninae, and Acheilognathinae did not form monphyletic group respectively. Leuciscinae was divided into southern group and east Asian group. The southern group of Leuciscinae was monphyletic, while east Asian group of Leuciscinae, Culterinae, Xenocyprinae and Hypophthalmichthyinae formed a monphyletic group. Tinca tinca, Leuciscus leuciscus baicalensis, Abramis brama orientalis and Rutilus rutilus lacustris formed a monphyletic group, which supported that tinca tinca should be kept in leuciscinae.