基于线粒体CO 1基因序列的DNA条形码在鲤科鲌属鱼类物种鉴定中的应用

本研究探讨了线粒体CO1基因作为DNA条形码对鲌属鱼类进行物种鉴定的可行性。研究中获得了鲌属4种鱼类共32个个体长度为816bp的CO1基因序列。利用MEGA软件计算鲌属鱼类种间及种内遗传距离，利用邻接法、最大简约法、最大似然法和Bayesian方法分别构建分子系统树。结果显示，鲌属鱼类的种间遗传距离显著大于种内遗传距离。在系统树中，鲌属鱼类每一物种的个体分别形成各自独立的分支。基于CO1基因的DNA条形码在识别鲌属鱼类物种方面和传统形态学基本一致，而且该基因可以探讨鲌属鱼类种间的系统发育关系。本研究表明以CO1基因作为鲌属鱼类DNA条形码进行物种鉴定具有一定的可行性。

Application of DNA barcoding based on the mitochondrial CO1 gene sequences in classification of Culter (Pisces: Cyprinidae)

DNA Barcoding is becoming more and more attractive to biologists as a new method for species identification. The core idea of DNA barcoding is based on the fact that species can be differentiated by short pieces of standard gene sequences. It is very important to choose appropriate genetic marker for species identification. Mitochondrial CO1 gene sequence was a popular marker of DNA barcoding for species identification in the kingdom of animals. In this paper, we discussed the validation of CO1 gene sequence to efficiently identify the species of genus Culter. Original nucleotide sequence data of partial mitochondrial CO1 gene, about 816 base pairs, were collected from 4 species of Culter and totally 32 specimens. Sequences analysis was conducted by using MEGA3.1. Genetic variation among species and variation within species were calculated, and it was found that pairwise genetic distance among 4 species was more than 2%, and obviously higher than the distance within a species. Phylogenetic analysis was carried out with different methods, including neighbor-joining, maximum parsimony, maximum likelihood and bayesian analysis. The topology of each final trees revealed that all individuals of each species formed a strong monophyletic group. Specie identification with CO1 sequences in Culter supported the taxonomy based on morphological characters, and it was proposed that CO1 sequences could be a probable marker to resolve the phylogenetic relationship of the genus. The conclusion of our research suggested that mitochondrial CO1 gene was a valid DNA barcoding gene for specie identification in genus Culter.