中国近海11种鳀科鱼类分子系统发育的初步研究

On phylogenetic relationship of 11 engraulidae species in China sea areas

以鳀科鱼类为研究对象,分析其线粒体16S rRNA基因片断序列,探讨了5属11种中国鳀科鱼类的亲缘关系。得到16S rRNA可比序列长度为472~501 bp,共存在20个插入/缺失,125个变异位点。总体上看,序列中转换多于颠换,转换/颠换之比为1.4。根据16S rRNA基因片段差异计算的种间遗传距离从0.22%（黄吻棱鳀和中颌棱鳀,刀鲚和凤鲚）到18.54%（长颌棱鳀和康氏侧带小公鱼）,以金色小沙丁鱼作为外群构建的系统树,棱鯷属依次与鲚属、黄鲫属相聚,再与棱鳀属的赤鼻棱鳀相聚;最后与鳀属和侧带小公鱼属形成的分支相聚。赤鼻棱鳀自成单独的一支,建议将赤鼻棱鳀从棱鳀属中划分出来。

To evaluate the phylogenetic relationship of 11 species of Engraulidae in China,the mitochondrial 16S rRNA gene was amplified using PCR techniques.About 600 bp length 16S rRNA gene fragments were obtained and sequenced.After being aligned,the fragments of 472-501 bp（16S rRNA） nucleotide sequences which could be used for sequence analysis were obtained.The genetic information indexes,including Kimura-2 parameter genetic distance,basal composition and phylogenetic trees were generated using MEGA3.1 software.Of the 16S rRNA aligned base pairs,25 insertions/deletions were detected and 125 sites were variable.The mutation sites were mainly transitional and transversional.Transitions were found to be more common than transversions.The genetic distances between species ranged from 0.22%（T.vitrirostris and T.mystax,C.ectenes and C.mystus） to 18.54%（S.commersonii and T.setirostris）.Molecular phylogenetic tree was constructed by NJ methods based on the sequences,with Sardinella lemuru as the designated outgroup.The tree based on 16S rRNA gene indicated a closer relationship between T.dussumieri and T.hamiltonii.The genus Thryssa showed close relationship with Coilia,and then clustered with Setipinna.The former cluster gathered with T.kammalensis.Finally,they clustered with the Stolephorus and Engraulis.And T.kammalensis was separated from Thryssa.The results implied that T.kammalensis should be considered as a new genus.