Population genetic structure of Aedes albopictus (Diptera: Culicidae) in China inferred by microsatellite and association with knockdown resistance mutations

Abstract Background: Aedes albopictus is considered to be the main vector of dengue fever and Chikungunya fever in China. Mosquito control is an important component of the integrated programs to prevent dengue fever transmission. In this study, to provide technical support for future genetic control of mosquitoes, the genetic structure of Ae. albopictus population in China was analyzed and the correlation between genetic variations within Ae. albopictus population and kdr mutation was explored. Methods: Seventeen collection sites from 11 provinces (municipalities) of Ae. albopictus were collected from 2016 to 2021 in China, including most regions in the distribution area. Genomic DNA was extracted from individual adult mosquito using the DNAzol reagent. Eight microsatellite loci were finally selected for genotyping. Population genetic structure and demographic inference were analyzed using the software. Pearson correlation coefficient R was used to examine the association between the intra-population genetic variation and kdr mutation. Results: The considered eight microsatellite loci, scored in 453 mosquitoes across the 17 localities from North to South of China. The variation analysis showed that most variation occurred within individuals, whereas only about 9% of the total variation was detected among populations. Three gene pools were inferred by Bayesian analysis, in which the overall trend was that the northern populations belong to gene pool I (red), the eastern populations belong to III (blue), and the southern populations belong to three different gene pools. We also observed that the greater the genetic difference (FST), the lower the wild-type frequency of F1534 of VSGC gene in the same population. Conclusions: The degree of genetic divergence of Ae. albopictus in China was very low among the populations. These populations can be divided into three genetic gene pools. The gene pool of the northern and eastern Chinese populations was relatively simple, and southern populations were heterogeneous. The greater the genetic difference within the population, the larger the mutation rate of knockdown resistance, indicating that frequent migration among Ae. albopictus populations in China maybe a major factor in the increasing insecticide resistance.