DNA条形码技术在鉴定蛆症异蚤蝇中的应用

Application of DNA barcoding techniques to species identification of Megaselia scalaris

目的:建立应用DNA条形码技术鉴定蛆症异蚤蝇的方法。方法:分别提取在口岸检疫中截获的双翅目幼虫和成虫的基因组DNA,利用节肢动物线粒体细胞色素氧化酶I(COI)的通用引物进行DNA扩增。PCR产物直接测序,测序引物同扩增引物,得到清晰可读的665 bp COI的DNA片段碱基序列。与GenBank中相近的序列进行比较,并用ClustalW2在线建立NJ系统发育树。结果:成虫和幼虫COI的DNA序列100%相同,与GenBank中公布的长度为559 bp的蛆症异蚤蝇的COI相应片段相似性高达98.9%,与同属其他种类的可比片段的DNA序列相似性则低于90%。结论:根据结果可以判断所截获的双翅目昆虫为蛆症异蚤蝇。本文的研究再一次证明了DNA条形码技术可以直接应用于昆虫种类的鉴定。

Objective：To establish a method of application DNA Barcoding techniques to the species identification of Megaselia scalaris.Methods：Genomic DNA were extracted from both the Diptera adult and larva intercepted from the imported waste paper.PCR was performed with the arthropod degenerate mitochondrial cytochrome oxidase（COI） primers.Sequencing primers were same with the PCR ones.665 bp COI sequences were obtained from the PCR product sequenced directly.Sequences blasted in the GenBank,and a NJ-tree of the larva,adult and related species was bulit with Clustal W2 on line.Results：Sequences of the compared COI fragments from the adult and larva were 100% identical,which was 98.9% identical to the published 559 bp COI fragment of Megaselia scalaris in the GenBank,identification was less than 90% compared with other species from the same genus.Conclusion：Based on these results,we could conclude that the intercepted species is Megaselia scalaris.In this study we confirmed again that application of DNA Barcoding to species identification of insect is desirable and with high confidence.