秀丽白虾线粒体16S rRNA基因序列及长臂虾亚科系统进化初步分析

Preliminary Analysis on Mitochondrial 16S rRNA Gene Sequence of Exopalaemon modestus and Phylogeny of Palaemoninae

旨在了解秀丽白虾线粒体16S rRNA基因序列及线粒体16S r RNA基因在虾类物种鉴定及系统分类中的作用,采用PCR特异扩增测序的方法,对秀丽白虾(Exopalaemon modestus)的16S rRNA基因片段进行了分析,并探讨了长臂虾亚科虾类的系统发育关系。结果表明:54尾秀丽白虾16S r RNA基因共发现5种单倍型和8个变异位点。13种长臂虾间的遗传距离在0~0.2614之间,7个属间的遗传距离为0.1344~0.2769。NJ法和ME法构建的系统进化树显示,除洁白长臂虾外,同属的不同种先聚成一支,其中东方白虾和脊尾白虾亲缘关系最近。长臂虾属和小长臂虾属亲缘关系很近,长臂虾属为多起源;推测洁白长臂虾与宽额拟瘦虾之间的分化时间距今约22.34百万年。本研究结果表明,线粒体16S rRNA基因序列不能单独对长臂虾亚科虾类进行物种鉴定,但进行系统分类和亲缘关系分析是可行的。

To study 16 S rRNA gene sequence of Exopalaemon modestus and the role of 16 S rRNA gene in species identification and phylogenetic taxa,mitochondrial 16 S rRNA gene sequence of Exopalaemon modestus was analyzed by PCR amplification and sequencing.The phylogenetic relationships of the subfamily(Palaemoninae)were also discussed.The results showed that 5 haplotypes and 8 variable loci were found in 54 individuals.The genetic distance among 13 species of shrimps ranged from 0 to 0.2614.The genetic distance among 7 genus ranged from 0.1344 to 0.2769.The molecular phylogenetic trees constructed by NJ and ME method indicated that different species of the same genus clustered into one branch first except Palaemon concinnus,and Exopalaemon orientis was the closest related species to Exopalaemon carinicauda.Palaemon and Palaemonetes had the most closet phylogenetic relationship and the genus Palaemon was polyphyletic.Palaemon concinnus and Leandrites deschampsi were differentiated about 22.34 million years ago presumably.This study indicates that mitochondrial 16 S rRNA gene could not be used to identify the species of the subfamily Palaemoninae alone,but it is feasible for systematic classification and analysis of genetic relationship.