新疆几种裂腹鱼类系统发育关系探讨

通过PCR扩增获得了分布于新疆的裂腹鱼亚科(Schizothoracinae)4属7种鱼类的线粒体细胞色素b基因712bp序列.结果表明:Cytb基因片段的T,C,A和G碱基组成平均为30.1%,27.4%,25.6%和16.9%,共出现201个变异位点,其中简约信息位点162个,序列变异度为22.8%,转换/颠换为1...

Molecular Phylogeny of Schizothoracinae Fishes in Xinjiang Based on Mitochondrial Cytochrome b Gene Sequences

Totally 712 bp fragments of mitochondrial cytochrome b gene of 7 species in 4 genera of Schizothoracinae fishes in Xinjiang were amplified and sequenced. For the Cyt b gene, the average nucleotide contents of T, C, A and G were 30.1%, 27.4%, 25.6% and 16.9% respectively. There were 201 variable sites, of which 162 were parsimony-informative sites, their sequence variability was 22.8%, the transition/transversition was 15.03, and the nucleotide substitution occurred mostly at the third position. Three molecular phylogenetic trees were constructed with different methods, in which the neighbor-joining (NJ) tree and maximum parsimony (MP) tree were based on Kimura 2-parameter method, and the maximum likelihood (ML) tree was based on the best nucleotide substitution model. The results show that there were the close genetic relationships among the primordial-grade Schizothoracinae species and among the specialized-grade Schizothoracinae species. It is referred from the molecular evolution rate that the divergence of the 7 Schizothoracinae species occurred during the period from the late Pliocene to the Miocene with the uplift of the Qinghai-Tibet Plateau.