摘要
The genetic relationship between the toxic marine dinoflagellates Alexandrium tamarense and Alexandrium catenella, which share similar morphological characteristics and are clustered as a sister group on the phylogenetic tree based on 28S rDNA analysis was examined by DNA–DNA hybridization. This method has contributed to the information on relative comparisons of total sequences in the field of microbiology; however limited DNA–DNA hybridization studies have been carried out on microalgae, including dinoflagellates. The intragroup homology of DNA–DNA hybridization within the A. tamarense and A. catenella groups, that was identified on the basis of morphotypes, was 85.0%–99.8% in both cases, whereas the intergroup homology between these two groups was 62.5%–70.3%, which was lower than the intragroup homology. These percentages revealed that not only the rDNA sequences but also the total sequence reflects slight morphological differences between A. tamarense and A. catenella, indicating the possibility that strains identified as these two species could be differentiated as distinct groups based on the percentage obtained using DNA–DNA hybridization. The homology of A. tamarense with other Alexandrium species was low—37.1%–45.2% with A. tamiyavanichii, 41.0%–45.5% with A. affine, and 24.8%–35.8% with A. ostenfeldii. The relatedness between A. catenella and other Alexandrium strains tested (e.g. between A. catenella and A. tamiyavanichii was 39.0%–51.2%) was also lower than that between A. tamarense and A. catenella. Further, these percentages were consistent with the rDNA phylogenetic analysis, indicating that DNA–DNA hybridization might be a useful tool to understand the relatedness among Alexandrium species.
摘要译文
有毒的海洋甲藻亚历山大藻和链状亚历山大藻之间的亲缘关系，其中有着相似的形态特征和聚集为基于28S rDNA序列分析的系统发育树姐妹群进行了检查，DNA-DNA杂交。此方法已对在微生物学领域总序列的相对比较，对信息作出了贡献;但是有限的DNA-DNA杂交研究已经进行了微藻，包括甲藻。组内的同源性的DNA-DNA杂交的内A.藻和A.catenella基，被确定形态型的基础上，为85.0％-99.8％，在这两种情况下，而这两个组之间的组间的同源性为62.5％-70.3％，这比组内的同源性低。这些百分比表明不仅rDNA序列，而且总的顺序反映A之间轻微形态差异藻和A.链，使用DNA-DNA杂交，指示菌株鉴定为这两个物种可以区分作为基于百分比不同的组的可能性得到。 A的同源性藻与其他亚历山大藻是低37.1％-45.2％，与A. tamiyavanichii，41.0％-45.5％，与A.仿射和24.8％-35.8％，与A. ostenfeldii。 A.之间的关联性catenella和其他亚历山大株测试（如A. catenella和A. tamiyavanichii为39.0％-51.2％之间），比A.藻和A. catenella之间也更低。而且，这些百分比均与rDNA序列的系统发育分析一致，表明DNA-DNA杂交可能理解亚历山大物种间的相关性的有用工具。
Shoko Hosoi-Tanabe[1][2];Yoshihiko Sako[2]. Genetic differentiation in the marine dinoflagellates Alexandrium tamarense and Alexandrium catenella based on DNA–DNA hybridization[J]. Plankton and Benthos Research, 2006,1(3): 138-146