| 摘要: |
| 分析了几株自南海及东海分离的亚历山大藻的rDNA部分序列信息,其中包括核糖体大亚基(LSU)rDNA的5′端D1-D2区序列,以及5.8SrDNA和ITS区序列;同时也对实验室保种的部分来自其它国家和地区的亚历山大藻相关序列进行了测序和分析,并以此作为序列分析中的参考。采用ClustalX及MEGA2软件对所得到的序列信息进行了综合分析与对比。结果表明,分离自南海的塔玛亚历山大藻(Alexandrium tamarense)和分离自东海的链状亚历山大藻(A. catenella),即便是在ITS区和LSUrDNA等高变区,其序列信息也完全一致。与基因库中搜索到的其它亚历山大藻rDNA序列信息相比较,中国沿海的塔玛/链状亚历山大藻序列更接近于塔玛复合种的“亚洲温带”基因型。对于分离自南海的另外两株未定种的亚历山大藻,通过对比序列信息,发现它们与相关亚历山大藻(A.affine)非常接近。分离于我国台湾地区的微小亚历山大藻(A.minutum)在序列上与分离自新西兰的藻株相似,而与分离自欧洲的微小亚历山大藻藻株相差较大。中国沿海亚历山大藻rDNA序列信息的获得为针对有毒藻种设计特异性核酸探针, 发展灵敏快速的生物检测技术奠定了基础。 |
| 关键词: 赤潮 亚历山大藻 rDNA 序列分析 分子系统进化 |
| DOI： |
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| 基金项目:国家863青年基金项目资助,2002AA639420号;国家重点基础研究项目资助,2001CB409704号;中国科学院海洋研究所知识创新项目资助,200223107号。 |
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| SEQUENCE ANALYSIS AND MOLECULAR PHYLOGENETICS OF RIBOSOMAL RNA GENE OF ALEXANDRIUM (DINOPHYCEAE) STRAINS IN CHINA |
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TANG Xiang-Hai1,2, YU Ren-Cheng1, YAN Tian1, WANG Yun-Feng1, ZHOU Ming-Jiang1
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1.Key Laboratory of Marine Ecology & Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao,266071;2.Graduate School,Chinese Academy of Sciences,Beijing,100039
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| Abstract: |
| rDNA sequence that consists of highly conserved regions interspersed with variable regions, has been used extensively as phylogenetic and taxonomic indicators for a variety of organisms, making it an appropriate candidate for molecular phylogenetic studies over wide range of taxonomic levels. In this study, two highly variable regions of rDNA, the 5.8S ribosoma lRNA gene flanking internal transcribed spacers 1 and 2, and the 5' portion of large-subunit rDNA (encompasses so-called “D1” and “D2” hypervariable domains) of several strains of Alexandrium isolated from the East China Sea and the South China Sea, were amplified and sequenced for phylogenetic analysis. Besides, the same region of rDNA of several other strains of Alexandrium originated from other countries or regions were also sequenced serving as references in sequence analysis. The sequences were compared and analyzed with software ClustalX and MEGA 2. It was found that the sequences of all toxic A. tamarense and A. catenella isolated from Chinese coast were the same. Based on the phylogenetic study, the A. tamarense and A. catenella strains from China should belong to a genotype of “Temperate Asian”. Two other strains of Alexandrium, which have not been identified by morphotypical characteristics, were defined as genotype “affine”. The sequence of A. minutum isolated from Taiwan is very different from those of the species isolated from western European, but similar to the sequence of the strain from New Zealand. The sequence information could be further used for the development of genetic probes targeted on the toxic species of Alexandrium along Chinese coasts. |
| Key words: Red tide, Alexandrium, rDNA, Sequence analysis, Molecular phylogeny |
