Mitochondrial cytochrome b sequence variations and phylogeny of the East Asian bagrid catfishes

摘要

＜正＞ The mitochondrial DNA cytochrome b gene was sequenced from 8 bagrid catfishes in China. Aligned with cytochrome b sequences from 9 bagrid catfishes in Japan, Korea and Russia retrieved from GenBank, and selected Silurus meridionalis, Liobagrus anguillicauda, Liobagrus reini and Phenacogrammus interruptus as outgroups, we constructed a matrix of 21 DNA sequences. The Kimura’s two-parameter distances were calculated and molecular phylogenetic trees were constructed by using the maximum parsimony （MP） and neighbor-joining （NJ） methods. The results show that （i） there exist 3-bp deletions of mitochondrial cytochrome 6 gene compared with cypriniforms and characiforms; （ii） the molecular phylogenetic tree suggests that bagrid catfishes form a monophyletic group, and the genus Mystus is the earliest divergent in the East Asian bagrid catfishes, as well as the genus Pseudobagrus is a monophyletic group but the genus Pelteobagrus and Leiocassis are complicated; and （iii） the evolution rate of the East Asian bagr