基于线粒体细胞色素b基因序列的骨舌鱼科鱼类分子系统发育的研究

为阐明骨舌鱼科鱼类的遗传结构和进化关系,测定了美丽硬仆骨舌鱼Scleropages formosus的3个品种金龙(Gold arowana)、红龙(Red arowana)、青龙(Green arowana)细胞色素b(cyt b)基因全序列(1 141 bp),结合来自GenBank中珍珠龙Scleropages leichardti、星点珍珠龙S.jardini、非洲龙Heterotis niloticus、黑龙Osteoglossum ferrerirai、银龙O.bicirrhosum、海象Arapaima gigas的全序列,用邻接法(NJ)和最大简约法(MP)构建分子系统树,初步分析了骨舌鱼科鱼类的系统发育关系.NJ树和MP树均一致表明,骨舌鱼类为单系类群,分为4支,支持骨舌鱼科下设4个属(坚体鱼属Scleropages、异耳鱼属Heterotis、骨舌鱼属Osteoglossum、巨骨舌鱼属Arapaima)阶元的分类系统,4个属的系统关系与其形态、生态特征表型进化和地理分布较为一致.而金龙、红龙和青龙的mtDNA Cytb的碱基差异小于1%,说明这3个龙鱼品种还在同一种的水平上.

Molecular Phylogenetic Studies of Osteoglossidae Based on the Sequences of Complete Mitochondrial Cytochrome b Gene

The present study aimed to clarify the genetic structure and evolutionary relationships within Osteoglossidae,using complete mitochondrial cytochrome b(Cyt b) gene sequences (1 141 bp) of three breeds of Scleropages formosus:Gold arowana,Red arowana and Green arowana,together with relevant sequences of Scleropages leichardti,S. jardini,Heterotis niloticus,Osteoglossum ferrerirai,O. bicirrhosum,Arapaima gigas obtained from GenBank.The phylogenetic trees constructed by two methods (NJ and MP) supported the same topology,and molecular phylogenetic relationships of fishes of the Osteoglossidae were constructed.Both of NJ tree and MP tree showed that fishes of the Osteoglossidae were a monophyletic group and classified Osteoglossidae into four genera,namely Scleropages,Heterotis,Osteoglossum,Arapaima,which were perfectly consistent with their morphological,ecological characteristics,evolution and geographic distribution pattern.Sequence variation of less than 1% in mtDNA Cyt b gene among three breeds of S. formosus suggested that they might represent the same species.