基于SSU rDNA和线粒体cox 1序列分析甲藻中不同生态类群的演化规律

应用SSU rDNA和线粒体cox 1序列研究甲藻(Dinoflagellate)中不同生态类群的演化关系。通过PCR扩增和测序获取4株甲藻SSU rDNA及其线粒体cox 1部分片段,结合GenBank中24株甲藻的相关序列,以Plasmodium falciparum为外群,构建ML树和NJ树,并采用自展支持度评估进化树分支结构,通过计算后验概率评估进化树整体结构,应用1sKH、SH、ELW和2sKH等方法评估两株ML树间的拓扑结构。结果显示,在由上述两序列构建的进化树上,底栖原甲藻均未与浮游原甲藻聚类,且前沟藻具有独特演化地位。表明联合选择SSU rDNA和线粒体cox 1序列构建的进化树在一定程度上能够反映出甲藻的演化规律。这为从基因层面深入探索甲藻中不同生态类群的演化关系初步奠定了基础。

Analysis of the evolution of different ecological groups of dinoflagellates based on SSU rDNA and mitochondrial cox 1 sequences

In this paper,we analyze the evolution of different ecological groups of dinoflagellates,based on SSU rDNA and mitochondrial cox 1 sequences.After PCR and sequencing,we obtained partial sequences of SSU rDNA and mitochondrial cox 1 for 4 dinoflagellates.By combining with related sequences of 26 dinoflagellates downloaded from GenBank,their maximum likelihood(ML) and neighbor-joining trees were constructed,using Plasmodium falciparum as the outgroup.The tree branch structure was evaluated by bootstrap support and calcu-lation of the posterior probability was employed to assess the overall tree structure.This was followed by assess-ment of the two ML tree topologies by 1sKH,SH,ELW and 2sKH tests.This analysis indicated that benthic Pro-rocentrum did not cluster with planktonic Prorocentrum in phylogenetic trees based on different genes.Analysis of Amphidinium carterae further supported their unique evolutionary positions.We conclude that the phylogenetic tree based on SSU rDNA and mitochondrial cox 1 substantially reflects the evolution of dinoflagellates.The re-sults of this study laid a foundation for further research on the evolution between different ecological groups of dinoflagellate from the genetic level.