厚蟹线粒体16S rRNA基因序列分析及系统发育研究

对我国沿海天津厚蟹6个群体、侧足厚蟹4个群体、伍氏仿厚蟹2个群体和日本仿厚蟹1个群体的线粒体16S rRNA基因片段进行了序列测定；结合从GenBank下载的其他厚蟹序列,分析了厚蟹分子系统发育关系.除天津厚蟹丹东群体的2个个体16S rRNA基因片段长度为526 bp外,其他天津厚蟹和侧足厚蟹均为525 bp；除日照...

Molecular phylogeny of the crab genera Helice and Helicana based on the partial sequences of mitochondrial 16S rRNA gene

The partial sequences of mitochondrial 16S rRNA gene of Helice tientsinensis (six populations), H. latimera (four populations), Helicana wuana (two populations) and H. japonica(one population) from the coast of China were determined and subjected to phylogenetic analysis with the inclusion of other species of Helice and Helicana obtained from the GenBank. The length of sequence of Helice tientsinensis and H. latimera was 525 bp, excluding 526 bp of two individuals from Dandong population of H. tientsinensis. Five haplotypes were found in them. The lengths of sequence of Helicana wuana and H. japonica were 525bp and 523bp respectively. There were no differences of sequence among individuals within populations of them, except Rizhao and Dandong populations. The A, T, G and C contents of them were similar, and the AT content(72.3%~73.7%)was higher than GC content. The resultant sequences of H. tientsinensis, H. latimera, H. wuana and H. japonica were 526bp long with 4 indels, of which 36 sites were variable and 26 sites were parsimoniously informative, and average transition/transversion ratio was 2.8. Among the five haplotypes, six individuals of H. latimera from Quanzhou and Ningbo populations and four individuals of H. tientsinensis from Ningbo and Rizhao populations shared one haplotype, and genetic distances among them were very small(0.19%~1.15%), implying that they may represent different morphotypes of the same species. Molecular phylogenetic trees indicated that the genera Helice and Helicana were monophyletic respectively, the large net genetic distances between them supported that they were updated from subgenus to genus. The molecular data also supported that the Pseudohelice and Parahelice were updated from subgenus to genus, and Helice/Chasmagnathus complex was divided into seven genera by morphology.