Microhabitat and spatial variation at HK isozyme loci in culex pipiens: Testing isolation by distance and isolation by ecology model

Abstract

© 2014(Publisher Name). All Rights Reserved. Culex pipiens L. (Diptera Culicidae) is of medical and veterinary importance as vector of various bacterial, filarial and arboviral disease pathogens, and is a major pest in urban areas. Understanding the population structure and gene flow among populations is critical for public health issues such as local dispersion pattern and spread of insecticide resistance. To determine the dispersion pattern of the Cx. pipiens samples across the southern part of the Pannonian Plain of Central Europe (testing Isolation by distance model), and at fine-scale level, between ecologically different larval habitats (testing Isolation by ecology model), we studied hexokinase (HK) genes. Because the polymorphism of HK genes is independent of insecticide use, spatial variation at HK loci provided valuable information on population connectivity of Cx. pipiens. Implementing STRUCTURE statistical analysis, a lack of structuring at individual level of “urban” and “rural” samples was observed. Landscape study rejected both ecological and iso-lation models which implies that different selection regimes of larval habitats and geographic distance do not influence on genotype portioning at HK system. Observed high genetic connectivity among samples throughout urban and rural environments indicated that gene flow is an important factor underlying genetic structure. This study pointed out that control measures restricted to urban areas are unlikely to be effective due to high gene flow between treated and untreated populations. Hence, designing a sustainable vector control strategy for the species with detectable gene flow, such as Cx. pipiens, must remain a regional effort.