从细胞色素b基因序列探讨笛鲷属的分子系统发生关系

测定了9种中国南海的笛鲷属鱼类的细胞色素b基因的部分序列,结合来自GenBank中1种分布于菲律宾和9种分布于美国大西洋的笛鲷属鱼类的相应同源序列,用邻接法和最大简约法构建分子系统树。结果显示:红鳍笛鲷(Lutjanuserythropterus)与红笛鲷(L.sanguineus)之间的同源序列碱基差异百分率只有0.32%,支持二者是同种异名的观点;中国南海的笛鲷属鱼类间的平均碱基差异要高于美国大西洋笛鲷属鱼类。在MP和NJ树中,美国大西洋笛鲷表现为亲缘关系较近,来源于中国南海的笛鲷鱼类相对集中在树的基部,分歧较大。这与所研究的笛鲷地理分布和地理隔离基本相一致,同时也说明中国南海笛鲷分化较早并且分歧较大。

Phylogenetic relationships of Lutjanus inferred from mitochondrial cytochrome b sequences

402 bp length fragments of mitochondrial cytochrome b gene from 9 species of genus Lutjanidae in South China Sea were cloned and sequenced.The resulting data were combined with homologous sequences of 9 species in western Atlantic in America and 1 species in Philippines of Lutjanidae downloaded from GenBank to form the analysis matrix.Molecular phylogenetic trees were constructed by neighbor-joining (NJ) and maximum parsimony (MP) methods based on 316 bp Cyt b gene sequences,with Cyprinus carpio as the designated outgroup.The results show that nucleotide sequence divergence is only 0.32% between Lutjanuserythropterus and L.sanguineus,supporting that L.erythropterus and L.sanguineus may be synonyms.The nucleotide sequence divergence among the South China Sea Lutjanidae is higher than that among the western Atlantic Lutjanidae.Both NJ and MP trees indicated a closer relationship in the western Atlantic Lutjanidae than in the South China Sea Lutjanidae.South China Sea Lutjanidae is basal in the NJ and MP tree and diverged before western Atlantic Lutjanidae.