| 摘要: |
| 对3种蛏类大竹蛏(Solengrandis),长竹蛏(Solen strictus)和小刀蛏(Cultellus attenuatus)的线粒体16SrRNA和COI基因片段序列进行了比较并对其系统学进行了初步研究。得到的序列总长度分别为472～481bp(16S)和658bp(COI)。3种蛏序列的碱基组成均显示出较高的A+T比例(16SrRNA基因62.1%;COI基因62.8%)。对位排序比较表明,16SrRNA片段种内个体间变异较小,3种类间存在128个碱基变异位点(其中包括127个简约信息位点)和5个插入/缺失位点,总共12个碱基长;COI片段有200个碱基存在变异,其中包括191个简约信息位点,不存在任何插入/缺失位点。数据分析结果表明16SrRNA和COI基因片段大竹蛏与长竹蛏两片段的遗传距离分别为0.0856和0.1712,两竹蛏类与小刀蛏的遗传距离分别为0.3054,0.2798和0.2662,0.2933。作者认为小刀蛏与竹蛏之间的遗传距离已达到科之间的水平,结果支持将其提升为刀蛏科的分类观点。3种蛏类线粒体16SrRNA和COI基因在种间明显的多态性,证实了16SrRNA和COI基因序列均普遍适用于蛏类种及以上阶元的系统学分析。 |
| 关键词: 竹蛏科 线粒体 16SrRNA基因 COI基因 |
| DOI： |
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| 基金项目:国家 863 计划项目(2002AA626020)资助 |
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| Sequence comparison and phylogenetic analysis of mtDNA 16S rRNA and COI gene fragments in three species of razor shell |
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| Abstract: |
| Sequence comparison and phylogenetic analysis of mtDNA 16S rRNA and COI gene fragments in three species of razor shell were made using PCR and direct sequencing. The three species are Solen grandis Dunker, Solen strictus Gould and Cultellus attenuatus Dunker. Nucleotide sequences of 472～481bp for 16S rRNA gene and 658bp for COI gene were obtained, respectively. A high percentage of A+T base composition in the two sequences was observed. Alignment indicated that variation level of intra-species was low in both sequences. Five indels and 128 variable sites were detected for 16S rRNA gene fragment（of which 127 were parsimony informative ones） across the three species. Two hundred polymorphic sites were detected in COI gene fragments and 191 were parsimony informative among the three species, with no indels. Genetic distances between S. grandis and S. strictus were 0.0856 (with 16S rRNA gene) and 0.1712 (with COI gene), respectively. However, with both sequence data, the genetic distances between the two Solen species and C. attenuatus were significantly larger, with numbers of 0.3054 and 0.2662 for 16S rRNA gene data, and numbers of 0.2798 and 0.2933 for COI gene data, respectively. These genetic distances have reached family level, and are in favor of the opinion that genus Cultellus should be promoted to family Cultellidae. |
| Key words: Solenidae mitochondrial DNA 16S rRNA gene COI gene |
