鲟形目线粒体16S rRNA的部分序列变异及系统发生

采用通用引物对3种鲟形目（Acipenseriformes）鱼类，中华鲟（Acipenser sinensis）、俄罗斯鲟（Acipenser gueldenstaedtii）和匙吻鲟（Polyodon spathula）的16S rRNA基因部分片段进行扩增，并与NCBI数据库中获得另外6种鲟形目鱼类相应的16S rRNA序列部分进行比较，探讨鲟形目2个科5个属共9个种之间的遗传变异和亲缘关系.数据合并后用于分析的序列共514 bp，变异位点29个，含简约信息位点16个，单一信息位点13个.以多鳍鱼目（Polypteriformes）多鳍鱼属Polypterus ornatipinnis为外群，采用部分16S rRNA序列基于Kimura双参数模型构建其系统发育关系，结果表明：MP法和NJ法得到系统树基本相同，其科、亚科和属的分化上基本与传统形态学分类相吻合，另外，欧鳇与鲟属鱼类的分化也并不明显.值得注意的是，鲟亚科6个种所划分出的3个分支恰恰分别归属于3个地理区域，欧鳇、闪光鲟和俄罗斯鲟主要集中于黑海和里海流域等地区；中华鲟和达氏鲟分布在西北太平洋，中国长江流域以及朝鲜；而高首鲟则分布于东太平洋.

Partial Sequence Variability of 16S rRNA in 9 Species of Acipenseriformes and Its Application in Phylogenetic Analysis

Partial nucleotide sequences of 16S rRNA were amplified using PCR techniques from three species (Acipenser sinensis,Acipenser gueldenstaedtii,Polyodon spathula) of Acipenseriformes.With sequences from other six species in NCBI database,the genetic variability and phylogenetic relationship were tested among 9 species from 2 families and 5 genera of Acipenseriformes.29 nucleotide variable positions including 16 parsimony infomative positions and 13 singleton positions were detected in analyzed 514 bp length sequence which were defined among the species.Taken Polypterus ornatipinnis as outgroup,similar phylogenetic trees were constructed by MP and NJ method among these 9 species of Acipenseriformes.The results showed that the differentiation of family,subfamily and genus was consistent with traditional morphological classification.Additionally,there was no significant difference between Huso huso and sturgeon.It is worth noting that 3 branches from 6 species in sturgeon subfamily belonged to 3 geographical regions.Among them,Huso huso,Acipenser stellatus and Acipenser gueldenstaedtii were mainly distributed in the Black sea and the Caspian sea basin,Acipenser sinensis and Acipenser dabryanus in the northwest Pacific,China yangtze river and Korea,while Acipenser transmontanus in the eastern Pacific.