Genetic variation in East-Adriatic populations of the Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae), inferred from NADH5 and COI sequence variability

Abstract

Abstract.In the last few decades, Aedes albopictus (Skuse) (Diptera: Culicidae) (= Stegomyia albopicta), the so-called "Asian tiger mosquito", has spread from its native range in southeast Asia to Africa, the Middle East, Europe, the Americas, and Pacific islands. The spread of this species poses a risk to human health as it is considered to be one of the main vectors of dengue and other arboviruses. Aedes albopictus was reported in Croatia in 2004, thereafter it was discovered at several coastal localities in 2005 and to date it has spread to most coastal areas and islands in Croatia. Here we investigate the genetic variability of A. albopictus based on 39 individuals collected during the summer of 2009 along the East-Adriatic coast and islands of Croatia and Montenegro and using two mitochondrial molecular markers: cytochrome oxidase I (COI) and NADH dehydrogenase 5 (ND5). We identified a single ND5 haplotype, corresponding to the previously reported and worldwide-distributed haplotype H3. The COI marker was more variable and we identified four COI haplotypes. In order to identify the geographic origin of the populations that colonized Croatia, we performed phylogenetic analyses of ND5 and COI haplotypes in Croatian populations and other A. albopictus populations retrieved from the GenBank. The phylogenetic tree based on ND5 haplotypes revealed two well supported clades where the unique Croatian ND5 haplotype clustered with the majority of haplotypes originating from South-Asia, America, Europe, and Africa. Another smaller cluster consisted of only Brazilian haplotypes. The phylogenetic tree and haplotype network that resulted from the COI analysis also indicates that the three Croatian COI haplotypes cluster with European and American haplotypes. However the fourth Croatian COI haplotype was the only European haplotype that occurred in a separate clade (group) with Indian, South-Asian, and Brazilian haplotypes. This data suggests there have been several independent introduction events in Croatia.

Population genetic structure of Aedes albopictus in Penang, Malaysia

“…The pattern observed of genetic variation in populations of A. albopictus may be attributed to severe, repeated, or long periods of population bottlenecks that resulted in genetic variation losses because of random genetic drift (Nei et al, 1975;Birungi and Munstermann, 2002). In most areas in Penang, extensive and repeated insect control activities have involved source reduction and insecticide application, leading to the reduction and/or eradication of A. albopictus populations (Birungi and Munstermann, 2002;Žitko et al, 2011). As a result, reduced levels of genetic variation were observed in the current study.…”

“…As a result, reduced levels of genetic variation were observed in the current study. Another plausible explanation is that the Penang populations of A. albopictus were established by a small founding population with low mtDNA variability, and the populations successively expanded and established a few founder females in new geographic areas (Birungi and Munstermann, 2002;Žitko et al, 2011).…”

Molecular Characterization of the Asian Tiger Mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) in Northern Italy

“…Individuals with tropical mitochondrial haplotypes were found in 2009 in Croatia [12]. The identity of the corresponding nuclear DNA remained unknown.…”

“…Its expansion all over the world may contribute to obtain a mosaic of genetically distinct populations expressing different abilities to transmit arboviruses [4][5][6][7]. Studies using cytochrome C oxidase subunit I (COI) and NADH dehydrogenase subunit 5 (ND5) genes showed a low level of polymorphism of the mitochondrial DNA (mtDNA), but revealed differences between tropical and subtropical populations [8][9][10][11][12]. Low levels of mtDNA polymorphism can be associated with the founder effect [8], and also with the presence of maternally inherited symbiotic bacterium Wolbachia in A. albopictus [13].…”

“…We studied genetic diversity within A. albopictus from four sampling sites based on analyses of the mitochondrial and nuclear sequences. Since in Croatia, only one common mitochondrial haplotype for the ND5 gene and four different mitochondrial haplotypes for the COI gene were detected [12] and in Cameroon four other mitochondrial haplotypes of the COI gene were found in the absence of polymorphism of the ND5 gene [11], we selected COI as the most informative gene for analysis of A. albopictus from different sampling sites. COI is also used for Barcoding and published sequence data of different geographical origin are available for analysis.…”