No geographical population structure of malaria vectors Anopheles gambiae and Anopheles coluzzii but weak structure in Anopheles arabiensis within Burkina Faso: implications for vector control and gene drive implementation

Abstract Background Malaria control tools are nowadays challenged by the expansion and persistence of insecticide resistance in the malaria vector along with the changes in vector behaviour. To complement and reinforce the existing control tools, innovative vector control methods, such as gene drives, are currently under development. Understanding the Anopheles gambiae sensu lato ( An. gambiae s.l. ) population structure is crucial for the implementation of genetic control tools and improvement of existing control strategies. Here we investigated the genetic diversity and population structure of Anopheles gambiae s.l. populations from three climatic zones in Burkina Faso. Method Mosquito specimens were collected across three ecological settings in Burkina Faso using pyrethroid spray catches. The whole genomes of Anopheles gambiae s.l. specimens were sequenced as part of the Anopheles gambiae 1000 Genomes Project. Data were analysed using MalariaGEN Resources to investigate the genetic diversity and the population structure. Results The results revealed the absence of geographical population structure in Anopheles coluzzii and Anopheles gambiae sensu stricto ( An. gambiae s.s. ) collected in the three climatic zones, implicating high gene flow within the country. Anopheles arabiensis showed a structure that separates Hauts-Bassins samples in the Soudanian zone from other An. arabiensis samples. The cryptic species ( An. goundry and An. tengrela ) previously identified in the country were not detected in this study. Our findings also indicate population expansion in An. gambiae s.l. ; however, An. arabiensis populations show evidence of a smaller population size or a bottleneck. Conclusion Our findings could indicate that An. arabiensis has a distinct demographic history. The population structure of An. gambiae s.s. and An. coluzzii across the country is characterized by a lack of geographical differentiation. These findings have important implications for both current vector control strategies and the potential implementation of gene drive technologies. Indeed, the lack of geographical population structure offers the potential for the rapid spread of gene drive constructs.