Population structure of a vector of human diseases

Abstract

Aedes aegypti, the major vector of dengue, yellow fever, chikungunya, and Zika viruses, remains of great medical and public health concern. There is little doubt thatthe ancestral home of the species is Africa. This mosquito invaded the New World400-500 years ago and later, Asia. However, little is known about the genetic structure and history of Ae. aegypti across Africa, as well as the possible origin(s) of theNew World invasion. Here, we use ∼17,000 genome-wide single nucleotide polymorphisms (SNPs) to characterize a heretofore undocumented complex picture of thismosquito across its ancestral range in Africa. We find signatures of human-assistedmigrations, connectivity across long distances in sylvan populations, and of local admixture between domestic and sylvan populations. Finally, through a phylogeneticanalysis combined with the genetic structure analyses, we suggest West Africa andespecially Angola as the source of the New World's invasion, a scenario that fits wellwith the historic record of 16th-century slave trade between Africa and Americas.