Patterns of spatial genetic structures in Aedes albopictus (Diptera: Culicidae) populations in China

Abstract

AbstractBackgroundThe Asian tiger mosquito,Aedes albopictus, is one of the 100 worst invasive species in the world and the vector for several arboviruses including dengue, Zika and chikungunya viruses. Understanding the population spatial genetic structure, migration, and gene flow of vector species is critical to effectively preventing and controlling vector-borne diseases. Little is known about the population structure and genetic differentiation of nativeAe. albopictusin China. The aim of this study was to examine the patterns of the spatial genetic structures of nativeAe. albopictuspopulations, and their relationship to dengue incidence, on a large geographical scale.MethodsDuring 2016–2018, adult femaleAe. albopictusmosquitoes were collected by human landing catch (HLC) or human-bait sweep-net collections in 34 localities across China. Thirteen microsatellite markers were used to examine the patterns of genetic diversity, population structure, and gene flow among nativeAe. albopictuspopulations. The correlation between population genetic indices and dengue incidence was also examined.ResultsA total of 153 distinct alleles were identified at the 13 microsatellite loci in the tested populations. All loci were polymorphic, with the number of distinct alleles ranging from eight to sixteen. Genetic parameters such as PIC, heterozygosity, allelic richness and fixation index (FST) revealed highly polymorphic markers, high genetic diversity, and low population genetic differentiation. In addition, Bayesian analysis of population structure showed two distinct genetic groups in southern-western and eastern-central-northern China. The Mantel test indicated a positive correlation between genetic distance and geographical distance (R2 = 0.245,P = 0.01). STRUCTURE analysis, PCoA and GLS interpolation analysis indicated thatAe. albopictuspopulations in China were regionally clustered. Gene flow and relatedness estimates were generally high between populations. We observed no correlation between population genetic indices of microsatellite loci inAe. albopictuspopulations and dengue incidence.ConclusionStrong gene flow probably assisted by human activities inhibited population differentiation and promoted genetic diversity among populations ofAe. albopictus. This may represent a potential risk of rapid spread of mosquito-borne diseases. The spatial genetic structure, coupled with the association between genetic indices and dengue incidence, may have important implications for understanding the epidemiology, prevention, and control of vector-borne diseases.