基于线粒体16S rRNA与COI基因序列的刻肋海胆属系统发育研究

本研究以16S rRNA和细胞色素氧化酶I(Cytochrome oxidase subunit I,COI)基因片段序列为标记,以杂色角孔海胆(Salmacis sphaeroides)为外群,基于距离法(NJ)、最大简约法(MP)和最大似然法(ML)分别构建分子系统树,对刻肋海胆属(Temnopleu rus)进行了系统发育学研究.结果表明,哈氏刻肋海胆、细雕刻肋海胆、T.alexandri三者亲缘关系较近,芮氏刻肋海胆和T.michaelseni亲缘关系较近.两个基因片段的核苷酸替代速率顺序为COI＞ 16S rRNA.以3.49％/百万年的核苷酸分歧速率应用于5种海胆的COI基因片段,推断5种海胆分化事件主要发生在约500～590万年前,为中新世晚期(Late Miocene)或上新世早期(Early Pliocene).

Molecular Phylogenetics of Genus Temnopleurus Based on 16S rRNA and COI Sequences

The partial sequences of mitochondrial COI and 16S rRNA of five genus Temnopleurus were compared to study their phylogenetic relationship.Taking Salmacis sphaeroides as outgroup,phylogenetic trees were separately constructed based on neighbor-joining,maximum parsimony and maximum likelihood methods.The results showed T.hardwickii,T.toreumaticus and T.alexandri formed into one clade,and there was a closer relationship between T.reevesii and T.michaelseni.Sequence analysis indicated that the nucleotide substitution rates of two gene segments was COI >16S rRNA.Based on the divergence rate of 3.49% per million years of COI fragment,their differentiation could happen between 5.0 and 5.90 million years ago,in the Late Miocene or Early Pliocene.