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【目的】对盾蚧亚科昆虫的基因序列进行研究,探讨EF-1a基因在该亚科昆虫中的分子进化机制,为我国盾蚧亚科昆虫的分类与鉴定提供理论依据。【方法】以EF-1a为目的基因,对分布于中国的盾蚧亚科雪盾蚧属、白轮蚧属、并盾蚧属、盾蚧属、矢尖蚧属、拟轮蚧属和围盾蚧属7个属13种蚧虫以及2个外群的EF-1a基因进行特异性扩增和测序。使用ClustalX1.83和MEGA4.0系统发育分析软件,对所得DNA序列的碱基组成、碱基替换、遗传距离等进行分析;通过碱基替换饱和性分析进行了信号检验;在MEGA4.0软件中采用最大简约法、邻接法和最小进化法对盾蚧亚科7属的系统发育关系进行分析。【结果】(1)盾蚧亚科7属的EF-1a序列中,T、C、A、G的平均含量分别为23.5%,25.6%,25.5%和25.4%,A+T的含量为49%,G+C的含量为51%。(2)转换频率是颠换频率的1.3倍,转换主要发生在A与G之间,颠换主要发生在A与T之间。(3)碱基替换饱和性分析显示,EF-1a数据集有较强的系统发育信号。系统发育树的结果显示,白轮蚧属、并盾蚧属和雪盾蚧属属同一支,盾蚧属和矢尖蚧属属同一支,围盾蚧属和拟轮蚧属属同一支。【结论】EF-1a基因是盾蚧亚科属级分类单元分子系统发育的有效基因标记之一。
【Objective】 The aim of this study was to investigate the gene sequence of subfasciridae in the genus Dendroctonus so as to explore the molecular evolution mechanism of EF-1a gene in this subfamily insect and to provide a theoretical basis for the classification and identification of subfasciridae in our country. 【Method】 The EF-1a gene was used to detect the gene sequence of EF-1a in the genus Sarcoptes spp., Genus Belongo, Genus Ranunculaceae, Genus Ranunculaceae, The 13 insects of 7 genera of the genus Sarcophagus and the EF-1a gene of 2 outliers were amplified and sequenced. Using ClustalX1.83 and MEGA4.0 phylogenetic analysis software to analyze the base composition, base replacement and genetic distance of the obtained DNA sequence, the signal was tested by base substitution saturation analysis. In MEGA 4.0 software The phylogenetic relationships of seven genera of the subfamily Gaffida were analyzed using the maximal parsimony method, the adjoining method and the minimal evolution method. 【Result】 (1) The average content of T, C, A and G in 7 genera of subfamilies of Dendrocalamus were 23.5%, 25.6%, 25.5% and 25.4%, respectively. The content of A + T was 49 %, The content of G + C is 51%. (2) The conversion frequency is 1.3 times the frequency of the transversion, the conversion occurs mainly between A and G. The transversion occurs mainly between A and T. (3) Base substitution saturation analysis showed that EF-1a dataset has strong phylogenetic signal. The results of phylogenetic tree showed that the genus Beltacea and the genus Sarcodina and the genus Suaeda belong to one and the same one. 【Conclusion】 EF-1a gene is one of the effective genetic markers in the molecular phylogeny of subfamily Genus Taxodiaceae.