Abstract
BackgroundAlthough Sri Lanka is considered as a malaria-free nation, the threat of re-emergence of outbreaks still remains due to the high prevalence and abundance of malaria vectors. Analysis of population genetic structure of malaria vectors is considered to be one of the vital components in implementing successful vector control programmes. The present study was conducted to determine the population genetic structure of three abundant malaria vectors; Anopheles subpictus sensu lato (s.l.), Anopheles peditaneatus and Anopheles vagus from five administrative districts in two climatic zones; intermediate zone (Badulla and Kurunegala districts) and dry zone (Ampara, Batticoloa and Jaffna districts) of Sri Lanka using the mitochondrial gene, cytochrome c oxidase subunit I (COI).MethodsAdult mosquitoes of An. subpictus s.l., An. peditaeniatus, and An. vagus were collected from five study sites located in five districts using cattle baited traps and backpack aspirators. Representative samples of each species that were morphologically confirmed were selected from each locality in generating COI sequences (> 6 good quality sequences per species per locality).ResultsAnopheles subpictus s.l. specimens collected during the study belonged to two sibling species; An. subpictus ‘A’ (from all study sites except from Jaffna) and An. subpictus ‘B’ (only from Jaffna). The results of haplotype and nucleotide diversity indices showed that all the three species are having high genetic diversity. Although a high significant pairwise difference was observed between An. subpictus ‘A’ and ‘B’ (Fst> 0.950, p < 0.05), there were no significant genetic population structures within An. peditaeniatus, An. vagus and An. subpictus species A (p > 0.05), indicating possible gene flow between these populations.ConclusionsGene flow among the populations of An. peditaeniatus, An. vagus and An. subpictus species A was evident. Application of vector control measures against all mosquito species must be done with close monitoring since gene flow can assist the spread of insecticide resistance genes over a vast geographical area.
Highlights
Sri Lanka is considered as a malaria-free nation, the threat of re-emergence of outbreaks still remains due to the high prevalence and abundance of malaria vectors
This study aims to analyse the population genetic structure of another three important malaria vectors An. subpictus, An. peditaneatus, and An. vagus using the mitochondrial gene, cytochrome c oxidase subunit I (COI), for the first time in Sri Lanka
The present study reports the presence of two genetic entities of An. subpictus; “species A” and “species B” confirming the results of the previous study on barcoding of Anopheline mosquitoes from the same study sites [33]
Summary
Sri Lanka is considered as a malaria-free nation, the threat of re-emergence of outbreaks still remains due to the high prevalence and abundance of malaria vectors. Knowledge on the population genetic structure of mosquito vectors of disease is vital in understanding their vectorial capacity, in increasing the efficiency of existing vector control programmes and in implementing novel vector control strategies [1,2,3,4,5] For these reasons, population genetic structures of Anopheles mosquitoes, many species of which are vectors of malaria, have been extensively studied, e.g. Anopheles arabiensis [6, 7], Anopheles baimaii [8], Anopheles culicifacies [9], Anopheles dirus [3, 10, 11], Anopheles funestus [12], Anopheles gambiae [13, 14], Anopheles maculatus [15], Anopheles minimus [16], Anopheles sinensis [17,18,19] and Anopheles stephensi [20, 21]. Cytochrome c oxidase subunit I (COI) has been the most extensively used marker in studies on the genetic structure of mosquitoes, including An. sinensis [17], An. baimaii [8], An. dirus [10, 11, 22], An. lesteri [23], An. darling [24], An. stephensi [21] and Aedes albopictus [25]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
