基氏蠊螨的 18S rDNA 分子鉴定

目的 基于核糖体 18S rDNA 基因对基氏蠊螨进行分子鉴定。 方法 采集和分离储藏物样本,进行螨类的形态学鉴定。 提取单个螨的基因组 DNA,经 PCR 扩增、克隆和测序获得 COⅠ基因和 18S rDNA 基因,将所获序列进行 Blast 对比。 检索 GenBank 数据库中蠊螨属 18S rDNA 基因序列,利用 Clustal X 1. 83 软件进行多序列比对,基于MEGA X 软件进行序列分析并以邻接法(Neighbor-Joining,NJ)构建系统发育树。 结果 采集的样本经形态和 COⅠ基因双重鉴定为基氏蠊螨。 同时,所选取的 10 个基氏蠊螨的 18S rDNA 基因序列完全一致,均表现出 A / T 碱基偏向性,与同属的 Blattisocius tarsalis 和 Blattisocius everti 分别有 98. 73%和 98. 94%的同源性。 基于 18S rDNA 基因序列的系统进化树显示,基氏蠊螨与 Blattisocius tarsalis 和 Blattisocius everti 聚为一支。 结论 本研究建立了基氏蠊螨基于 18S rDNA 基因序列的分子鉴定方法,为基氏蠊螨的准确鉴定奠定基础。

Molecular identification of Blattisocius keegani based on 18S rDNA gene sequences

Objective To establish a molecular method for identification of Blattisocius keegani based on ribosomal 18S rDNA gene sequences.Methods Storage samples were collected and isolated.Genomic DNA of a single mite was extracted on morphological identification basis.The COⅠand 18S rDNA gene sequences were obtained by PCR amplification,cloning and sequencing.Then the obtained sequences were aligned using Blast software,and 18S rDNA sequences of Blattisocius were retrieved from the GenBank.Multiple sequence alignment was done using the software Clustal(version 1.83)with the known gene sequences.MEGA X software was used to analyze sequences,and the phylogenetic tree were constructed by neighbor-joining(NJ)method.Results The mites were identified as Blattisocius keegani based on COⅠand morphological identification.The amplified sequences of the ten Blattisocius keegani were identical,showing A/T bias.The sequence homology of Blattisocius keegani with Blattisocius tarsalis and Blattisocius everti was 98.73%and 98.94%,respectively.Phylogenetic analysis based on 18S rDNA genes showed that the three mites were clustered into one branch.Conclusion We have successfully established a method for identifying Blattisocius keegani on 18S rDNA sequences basis,which can be a foundation for accurate identification of Blattisocius keegani.