| 摘要: |
| 中国沿海10 种方蟹线粒体16S rRNA 基因部分片段的序列长度为517 bp～533 bp。它们的核苷酸序列A、T、G、C 的含量相似, A+T 的含量(69.8%～76.0%)明显高于G＋C 的含量; 10 种方蟹的16SrRNA 基因序列比对获得541 bp 的同源序列(含插入/缺失位点), 除插入/缺失位点外共检测到146 个变异位点, 其中81 个为简约信息位点。4 种厚蟹与2 种近方蟹的遗传距离(0.054～0.085)都显著小于与其他方蟹之间的遗传距离, 甚至明显小于与4 种厚蟹原本属于同一相手蟹科的2 种相手蟹之间的遗传距离(0.105～0.155); 而基于16S rRNA 基因片段序列采用NJ 法构建的系统进化树的拓扑结构也显示, 原本属于相手蟹科的侧足厚蟹、天津厚蟹、日本仿厚蟹和伍氏仿厚蟹没有与2 种相手蟹聚为一支, 而是最终与属于弓蟹科的2 种近方蟹聚为一大支, 且有高达99%的支持率。结果表明, 4 种厚蟹与2 种近方蟹的亲缘关系相对较近, 而与2 种相手蟹等其他方蟹的亲缘关系则相对较远。因此, 研究结果支持将4种厚蟹从相手蟹科移到弓蟹科。此外, 属于相手蟹科的2 种相手蟹聚为一支, 属于方蟹科的白纹方蟹和属于斜纹蟹科的瘤突斜纹蟹又各自成为一支; 表明16S rRNA 基因的分子数据支持其形态学分类结果的正确性, 提示上述4 科蟹类可能分别为单系。 |
| 关键词: 方蟹 16S rRNA 序列 系统发生 |
| DOI： |
| 分类号: |
| 基金项目:重庆文理学院引进人才专项(200803) |
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| Molecular phylogeny of grapsoid crabs (Crustacea, Decapoda) based on partial sequences of mitochondrial 16S rRNA gene，from China |
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XU Jing-ming
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| Abstract: |
| Partial sequences of mitochondrial 16S rRNA gene of ten species crabs of Grapsoidea from the coast of China were determined and subjected to phylogenetic analysis. The lengths of sequences were from 517 to 533bp. The A, T, G and C contents of them were similar, and AT contents(69.8%～76.0%)were higher than GC contents. Furthermore, the 541bp homologous segments were analyzed. The results showed that there were 146 variable sites and 81 parsimony-information sites in the nucleotides. The genetic distances between four species, Helice latimera, H. tientsinensis, Helicana japonica and H. wuana, and two species, Hemigrapsus sanguineus and H. penicillatus, were from 0.054 to 0.085, which were much smaller than that (0.105～0.155) between the four species of Helice and Helicana and two species of Chiromantes haematocheir and Parasesarma plicatum. However, the four species of Helice and Helicana and the two species of C. haematocheir and P. plicatum had been believed to belong to family Sesarmidae. Topological structure of the molecular phylogenetic tree constructed by 541bp homologous segments with Neighbor-Joining method showed that the four species of Helice and Helicana eventually were clustered into a distinct clade (99% confidence level) with the two species of H. sanguineus and H. penicillatus. But, the two species of Hemigrapsus belonged to family Varunidae. Therefore, the results supported that the four species of Helice and Helicana were transferred from Sesarmidae to Varunidae. In addition, the two species of C. haematocheir and P. plicatum that belong to family Sesarmidae were clustered into a distinct clade, and two other distinct clades were formed by Grapsus albolineatus and Plagusia squamosa that belong to families Grapsidae and Plagusiidae respectively. The results revealed that Grapsidae, Sesarmidae, Varunidae and Plagusiidae should be monophyletic, respectively. |
| Key words: Grapsoid crabs 16S rRNA Sequence Phylogeny |
