The genetic structure of Aedes aegypti populations is driven by boat traffic in the Peruvian Amazon

• Published in: PLoS neglected tropical diseases Vol. 13; no. 9; p. e0007552
• Main Authors: Guagliardo, Sarah Anne J., Lee, Yoosook, Pierce, Amanda A., Wong, Jacklyn, Chu, Yui Yin, Morrison, Amy C., Astete, Helvio, Brosi, Berry, Vazquez-Prokopec, Gonzalo, Scott, Thomas W., Kitron, Uriel, Stoddard, Steven T.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.09.2019; Public Library of Science (PLoS)
• Subjects: Admixtures; Aedes - genetics; Aedes - physiology; Aedes aegypti; Animal Distribution; Animals; Aquatic insects; Bayesian analysis; Bioinformatics; Biology and Life Sciences; Boats; Cities and towns; Cluster analysis; Clustering; Computer and Information Sciences; Dengue; Dengue fever; Dengue virus; Dispersal; Distance; Distribution; Engineering and Technology; Entomology; Environmental science; Fluvial transport; Funding; Gene Flow; Genes; Genetic aspects; Genetic markers; Genetic structure; Genetic vectors; Genetics; Genetics, Population; Geomorphology; Health aspects; Human Activities; Human diseases; Human subjects; Introduced species; Medicine and Health Sciences; Microsatellite Repeats; Microsatellites; Mitochondrial DNA; Mosquito Vectors - genetics; Mosquito Vectors - physiology; Mosquitoes; People and places; Peru; Population; Population density; Population genetics; Population structure; Population studies; Populations; Probability theory; River networks; Rural areas; Rural communities; Ships; Software; Statistical analysis; Statistical methods; Subpopulations; Supervision; Traffic; Transportation; Transportation networks; Tropical diseases; Urban areas; Urban environments; Vector-borne diseases; Vehicles; Viral diseases; Viruses; Yellow fever mosquito; Peru; Atlanta Georgia; Georgia; California; United States > US
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0007552

In the Americas, as in much of the rest of the world, the dengue virus vector Aedes aegypti is found in close association with human habitations, often leading to high population densities of mosquitoes in urban settings. In the Peruvian Amazon, this vector has been expanding to rural communities over the last 10-15 years, but to date, the population genetic structure of Ae. aegypti in this region has not been characterized. To investigate the relationship between Ae. aegypti gene flow and human transportation networks, we characterized mosquito population structure using a panel of 8 microsatellite markers and linked results to various potential mechanisms for long-distance dispersal. Adult and immature Ae. aegypti (>20 individuals per site) were collected from Iquitos city and from six neighboring riverine communities, i.e., Nauta, Indiana, Mazan, Barrio Florida, Tamshiaco, and Aucayo. FST statistics indicate significant, but low to moderate differentiation for the majority of study site pairs. Population structure of Ae. aegypti is not correlated with the geographic distance between towns, suggesting that human transportation networks provide a reasonable explanation for the high levels of population mixing. Our results indicate that Ae. aegypti gene flow among sub-populations is greatest between locations with heavy boat traffic, such as Iquitos-Tamshiaco and Iquitos-Indiana-Mazan, and lowest between locations with little or no boat/road traffic between them such as Barrio Florida-Iquitos. Bayesian clustering analysis showed ancestral admixture among three genetic clusters; no single cluster was exclusive to any site. Our results are consistent with the hypothesis that human transportation networks, particularly riverways, are responsible for the geographic spread of Ae. aegypti in the Peruvian Amazon. Our findings are applicable to other regions of the world characterized by networks of urban islands connected by fluvial transport routes.