基于线粒体COI基因的3种草蛉的系统发育关系分析

Phylogenetic Analysis of Three Green Lacewing Species(Neuropetra, Chrysopidae) Based on the Mitochondrial COI Gene

【目的】基于线粒体COI基因片段测序及分析,研究3种草蛉的系统发育关系,探讨DNA条形码准确鉴定草蛉种类的可行性。【方法】利用PCR扩增和测序技术,获得来自不同地区的12个样本3种草蛉的COI基因片段序列。运用DNAMAN软件对序列进行拼接比对,并从GeneBank数据库中下载9种草蛉的COI序列,利用MEGA 7.0软件对23条序列进行碱基序列分析、遗传距离分析及系统发育分析。【结果】序列保守位点469个,变异信息位点188个,简约信息位点150个,自裔位点38个。序列中A、T、G和C的含量分别为28.6%、41.1%、15.4%和14.9%;A+T含量(69.7%)高于G+C含量(30.3%),呈现出明显的A+T碱基偏好。草蛉种内遗传距离为0~0.005,种间遗传距离为0.022~0.184。在系统发育树(最大似然法/邻接法)中,同一属的物种以较高的置信度聚类在一起。【结论】基于COI基因片段的DNA条形码技术可以用于草蛉的分类鉴定。

[Purpose]To verify the feasibility of DNA barcoding in Chrysopidae species,phylogenetic analyses of lacewing species were based on the sequencing of mitochondrial COI gene.[Methods]Twelve sequences(fragment of COI gene)of three common green lacewing species from different regions were sequenced in this study.The sequences were assembled by using DNAMAN software,and nine lacewing species were downloaded from GeneBank.The analyses were performed with MEGA 7.0 software,including base composition and substitution,the genetic distance,and the phylogenetic trees of total 23 sequences.[Results]There were 469 conserved sites,188 variation sites,150 parsimony information sites,and 38 singleton sites on the mitochondrial COI gene.The content of A,T,G,and C base in all sites was 28.6%,41.1%,15.4%,and 14.9%,respectively.The content of A+T base was up to 69.7%and higher than G+C base,showing A+T base preference.The intraspecific genetic distance ranged from 0 to 0.005.Interspecific distances ranged between 0.022 and 0.184.The phylogenetic tree built by the maximum likelihood and neighbor-joining method showed that the species in the same genus can be clustered into the same branch with high branch bootstrap values.[Conclusion]The technology of DNA barcoding based on the COI gene sequence is applicable in the classification and identification of green lacewing species.