瓦氏黄颡鱼线粒体全基因组序列分析及系统进化

鲿科鱼类种类繁多, 外形相似, 形态学分类较为困难。为了给鲿科鱼类乃至鲇形目鱼类的系统进化研究积累基础资料, 文章采用参照近缘物种线粒体基因组设计覆盖全基因组引物的方法, 利用16对引物对瓦氏黄颡鱼(Pelteobagrus vachelli)线粒体全基因组进行扩增, PCR产物转化到质粒后测序, 最终获得线粒体基因组全序列, 其全长为16 527 bp, 包括2个rRNA基因、22个tRNA基因、13个编码蛋白质基因和一个非编码控制区。瓦氏黄颡鱼(P. vachelli)线粒体基因组结构和基因排列顺序与现已公布的鲇形目鱼类完全一致, 序列分析表明, 与鲇形目其他种属间具有较高的同源性, 与拟鲿属的同源性最高(91%)。利用鲇形目共4科6属9种及3个外群的线粒体全基因组序列, 从线粒体基因组水平探讨了鲿科鱼类及其在鲇形目的系统进化地位, 结果表明: 鲿科鱼类的瓦氏黄颡鱼(P. vachelli)、黄颡鱼(Pelteobagrus fulvidraco)、光泽黄颡鱼(Pelteobagrus nitidus)及越南拟鲿(Pseudobagrus tokiensis)构成一单系群; 拟鲿属与黄颡鱼属的关系较近; 黄颡鱼属中瓦氏黄颡鱼(P. vachelli)与光泽黄颡鱼(P.nitidus)的关系近于黄颡鱼(P. fulvidraco)。

Sequence and phylogeny analysis of the complete mitochondrial genome of Pelteobagrus vachelli

Morphological classification of Bagridae fishes is relatively difficult due to various kinds and similar shape, and the phyletic evolution is not very clear in some species. To provide basic data to the classification of Bagridae and Siluriformes fishes, the complete mitochondrial genome of Pelteobagrus vachelli was obtained by PCR based on 16 primers, which were designed on the basis of related species mtDNA sequences. The complete mitochondrial genome is 16 527 bp in length, including 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a non-coding control region. The organization and location of genes in the mitochondrial genome of Pelteobagrus vachelli were consistent with Siluriformes fishes published in GenBank. It has high homology with other families, such as Pseudobagrus Bleeker (91%) within Siluriformes. The phylogenetic analysis of Bagridae fishes was made from the level of mitochondria genome based on 9 species of 6 genera, which belong to 4 families of the Siluriformes, combining with 3 outgroups’ complete mitochondrial genomes sequences. The result indicated that Pelteobagrus vachelli, Pelteobagrus fulvidraco, Pelteobagrus nitidus and Pseudobagrus tokiensis of the Bagridae formed a monophyletic group; the Pseudoba-grus Bleeker and Pelteobagrus Bleeker formed a sister group. Moreover, Pelteobagrus vachelli was more relative to Pelteobagrus nitidus than Pelteobagrus fulvidraco in Pelteobagrus Bleeker.