Analysis of population genetic structure of Anopheles sinensis based on mitochondrial DNA cytochrome oxidase subunit I gene fragment

Objective To study the population genetic variation, genetic diversity and phylogenesis of Anopheles sinensis in China. Methods Anopheles sinensis samples collected from Shandong, Anhui, Jiangsu, Guizhou, and Yunnan Provinces and Guangxi Zhuang Autonomous Region with different geographical conditions between 2010 and 2012 were analyzed by mitochondrial DNA cytochrome oxidase subunit I(mt DNA- COI) gene amplification and sequencing. Bioedit 7.0 and Dna SP5.0 software was used to compare the gene sequences and analyze the population genetic structure, respectively. Arlequin 3.1was used to calculate the genetic distance and parameters of population differentiation. The relationship between the geographic and genetic distances was analyzed using IBD Web Service. PHYLIP 3.6 was used to construct the phylogenetic tree. Results PCR amplification and sequencing was performed successfully for 6 Anopheles sinensis populations containing 123 female mosquitoes. The length of mt DNA- COI gene fragment was 841 bp with an average A + T content of 71.2% and G + C content of 28.8%. High nucleotide diversity and genetic differentiation were observed among the Anopheles sinensis populations based on mt DNA- COI gene. Analysis of the molecular variance revealed a greater variation between populations than that within populations with isolation by distance between the populations. The Anopheles sinensis populations appeared to have undergone expansion, but the Yunnan population constituted an isolated branch in the phylogenetic tree. Conclusion mt DNACOI can serve as the molecular marker to analyze population genetic variation and phylogenesis of Anopheles sinensis. The Yunnan population shows a phylogenetic difference from the other populations analyzed in this study.