基于16S rRNA部分序列探讨12种鲹科鱼类的分子系统进化关系

Molecular phylogenetic relationship of Carangidae based on partial sequence of mitochondrial 16S ribosomal RNA gene

通过PCR扩增获得了中国海域的鲹科(Carangidae)8属9种的线粒体16S rRNA序列片段约598bp碱基,结合来自GenBank的3种鲹科鱼类的相应片段序列,并以大斑石鲈为外群,生成供系统发育分析的序列矩阵,利用MEGA version3.0软件分析序列的碱基组成、差异百分比和转换/颠换值等,应用最大简约法和邻接法构建系统树。结果显示:(1)鲹科鱼类的16S rRNA序列片段生成的序列矩阵中发现有碱基的插入和缺失,共有146bp变异位点,转换/颠换值为2.17,表明基因序列的突变未达到饱和,碱基平均差异为8.22%;(2)支持鲹科下设四个亚科(鲹亚科,亚科,鲳鲹亚科,鲹亚科)阶元的分类系统;(3)鲹亚科鲹属下不宜设亚属分类阶元;(4)及达副叶鲹与丽叶鲹亲缘关系近,16S rRNA序列片段碱基只有1.07%的差异,未达到分属水平。

The classification and evolutionary controversy between conventional morphological study, the 16S ribosomal RNA partial sequences relationship of Carangidae have remained much studies and molecular phylogenetic studies. In this of 9 species of 8 genera from Carangidae in China sea were amplified using PCR technique. Approximately, 598 bp gene fragments were obtained. The resulting data were combined with Pornadasys rnaculates designed outgroup and additional homologous sequences of 3 species from Carangidae downloaded from GenBank to form the analysis matrix. Nucleotide composition frequencies, Kimura-2 parameter genetic distance and transition/ transversion ratios were analyzed with the MEGA 3.0 software. Molecular phylogenetic trees were constructed by maximum parsimony （MP） and neighbor-joining （NJ） methods. The results were as follows： （1） There were insertions and deletions of base pairs in the aligned base pairs. 146 bp variable sites were found in the the analysis matrix. The average ts/tv ratio among all pairwise comparisons was 2.17, suggesting that the sequences had not reached saturation. The average percentage divergence was 8. 22%; （2） Fish classification system of Carangidae classified four subfamilies as Caranginae, Seriolinae, Trachinotinae, Chorineminae was acceptable, according to the partial sequence of mitochondrial 16S ribosomal RNA gene; （3） It＇s improper to define subgenus in Caranx of Caranginae; （4） Alepes djeddaba and Alepes kleinii had a close relationship, and should belong to the same Alepes genus, as the difference of partial 16S ribosomal RNA gene between them was only 1.07%.