基于线粒体COI基因的青海省44种蚤类的分子鉴定及系统发育分析

Molecular identification and phylogenetic analysis of 44 species of fleas in Qinghai Province,western China based on mt DNA COI gene sequence

【目的】本研究应用DNA条形码技术对青海省部分蚤种进行鉴定,旨在弥补蚤类传统形态分类方法的不足。【方法】通过PCR扩增3总科6科22属44种共182头蚤类标本的线粒体COI基因片段(约600 bp)并进行测序和比对;用K2P模型计算种内及种间遗传距离;以邻接法(neighborjoining,NJ)构建系统发育树。【结果】共测得182条COI基因序列片段(GenBank登录号:MG138154-MG138335);分析可知蚤种内遗传距离0.01%~2.90%,种间遗传距离4%~12%,种间遗传距离显著大于种内遗传距离。系统发育树显示,同一物种的不同个体均形成高支持率的单系,种间分支很明显。【结论】本研究结果表明COI基因可以用于蚤类的快速鉴定。

【Aim 】DNA barcoding method was used to identify flea samples from Qinghai Province,western China in order to make up the deficiency of the traditional morphological classification method in this study. 【Methods 】 The partial fragments（ about 600 bp） of the mt DNA COI gene of 182 flea individuals that belong to 3 superfamilies,6 families,22 genera and 44 species were amplified by PCR,sequenced and aligned. The intra-and inter-species genetic distances were calculated with K2 P model,and a phylogenetic tree was constructed with the neighbor-joining（ NJ） method. 【Results】Totally 182 COI gene sequences（ GenBank accession no. ： MG138154-MG138335） were sequenced successfully.The inter-species genetic distance（ 4%-12%） was significantly greater than the intra-species genetic distance（ 0. 01%-2. 90%）. The NJ tree obtained showed that samples of the same species formed monophyletic groups with high support value,and inter-species branches were clear. 【Conclusion】The results confirm that COI gene can be used in molecular identification of fleas.