Molecular identification of main vector fleas in Qinghai plague foci by DNA barcoding

Abstract

Objective To make up the limitations of traditional morphological classification methods, we identified vector fleas by DNA barcoding in Qinghai Province. Methods The mt DNA cytochrome c oxidase subunit Ⅰ(COⅠ) gene was amplified by PCR from 36 muscle tissues of fleas in 3 states, 2 cities and 5 counties of Qinghai Province, and the obtained COⅠ gene fragments were sequenced and aligned. The intra- and inter-species genetic distances were calculated with Mega 6 software using K2-P model and a phylogenetic tree was constructed with neighbor-joining (NJ) method. Results Totally 36 COⅠ gene sequences of 2 superfamilies, 4 genera and 6 kinds of vector fleas were measured, the average genetic distance was 0.119, and the intraspecific distance was 0.002 - 0.027, the interspecific distance was 0.039 - 0.207, and the interspecific genetic distance was significantly greater than the intraspecific genetic distance. NJ tree showed the same species had formed a single line with high support rate and interspecific branch was clear. Conclusion DNA barcoding is suitable for identification of vector fleas in Qinghai Province, may make up the limitations of traditional morphological classification methods. Key words: Siphonaptera; Cytochrome c oxidase subunit Ⅰ; DNA barcoding