Changes in the Genetic Structure ofAedes aegypti(Diptera: Culicidae) Populations in Queensland, Australia, Across Two Seasons: Implications for Potential Mosquito Releases

Abstract

Diseases transmitted by mosquitoes could be controlled if vector populations were replaced with strains that have reduced vector competency. Such a strategy is being developed for control of dengue virus which is transmitted by Aedes aegypti (L.) (Diptera: Culicidae). Mosquitoes artificially infected with the bacterium, Wolbachia pipientis Hertig, are being assessed as candidates for release at the adult stage with the aim of replacement of the wild population. Wolbachia can reduce the capacity of Ae. aegypti to transmit dengue virus and has potential to be driven through the natural population via a system of cytoplasmic incompatibility. Deployment of benign mosquito strains will be influenced by population size and structure of wild-type Ae. aegypti in proposed release areas, as well as rates of gene flow among populations in the wet and dry tropical seasons. Mosquitoes from northern Queensland were screened with genetic markers to find an optimal locality for release of a benign strain of Ae. aegypti. The inland towns of Chillagoe and Charters Towers and the coastal town of Ingham had mosquito populations that were partly genetically isolated from mosquitoes in other areas across both seasons. These locations may be suitable release sites if it is important for the released strain to be restricted during initial phases of implementation. Smaller genetic differences were also evident among other regions and were consistent over two seasons (wet and dry).

Developing Exon‐Primed Intron‐Crossing (EPIC) markers for population genetic studies in three Aedes disease vectors

“…Minimal “allele dropout” and null allele problems are additional benefits (Garrick & Sunnucks, ; Tay et al ., ) and Rp EPIC markers have been used in a variety of studies across genera (e.g., Backström et al ., ) and species/subspecies (e.g., Wang et al ., ), including those with wide geographic ranges (e.g., Tay et al ., ). Rp EPIC markers have also been used in previous studies of mosquitoes including the dengue vector Aedes aegypti (Endersby et al ., , ) and may be useful for species of the Finlaya and Stegomyia subgenus for “anchoring” orthologous genomic regions for genetic mapping and identifying chromosomal rearrangements.…”

“…In 2009, we looked to alternative markers and developed 2 Rp EPIC markers, RpS20b and RpL30a, and screened these and some microsatellite markers in Ae. aegypti from throughout Australia, and in parts of Thailand and Vietnam (Endersby et al ., , ). Markers were able to differentiate Ae.…”

Biological Invasions, Climate Change, and Genomics

“…A recent example is provided by the dengue vector mosquito, Aedes aegypti, whose source populations have traditionally been identified using mtDNA markers coupled with microsatellites (Endersby et al 2011;Brown et al 2014). These provide some indication of population sources and are currently used in countries such as Australia to locate source populations.…”

Understanding the Dengue Viruses and Progress towards Their Control

“…The genetic structure of St. aegypti populations and its implications for potential mosquito releases have been studied in Queensland, Australia [206], and Tri Nguyen village, Vietnam [207, 208]. Populations of St .…”