运用线粒体COⅠ基因分析8种石珊瑚系统发育关系

Phylogenetic relationship in 8 species of Scleractinian coral based on COⅠ sequences

中文关键词: 石珊瑚  线粒体CoⅠ  分子系统分类

英文关键词: Scleractinian  CoⅠ  Molecular systematics

中文摘要:

      通过COⅠ基因特异扩增测序，对徐闻地区的8种石珊瑚COⅠ基因片段序列进行了比较分析。结果表明，该片段的平均G+C含量为41.60 %。其中，第1密码子位点的含量最高（42.26%~44.05%，平均为43.45%）；转换和颠换多发生在第3密码子位点，比例高达70.30%和72.70%。采用临位连接（NJ）、最小进化（ME）和最大似然（ML）法对本研究中徐闻的8种及引自GenBank的20种石珊瑚COⅠ基因片段构建了系统发育树。结果显示，分子系统分类与传统分类略有差异，暗示珊瑚表型可塑性可能对传统分类存在影响。

英文摘要:

      Partial sequences of COⅠ genes from 8 species of Scleractinian in Xuwen area,Guangdong Province, were amplified and sequenced, and the base ratio and variations were analyzed . The result indicated that the average G+C content of this region accounted for 41.60%，while the codon position 1 was the highest, in the range of 42.26%~44.05%(43.45% in average). The proportion of transition and transversion was 70.30% and 72.70% respectively in codon position 3. The phylogenetic trees were also constructed based on COⅠ genes of these 8 samples and other 20 Scleractinian species recorded in GenBank. According to the Neighbour-joining, minimum-evolution and maximum-likelihood trees, molecular systematics was slightly different from the morphological conclusion, which suggested that morphological classification may be limited by coral skeletons plasticity. Consequently, the COⅠgene is one of the auxiliary tools to classify the phylogeny of Scleractinia.