Population genomics and geographic dispersal in Chagas disease vectors: Landscape drivers and evidence of possible adaptation to the domestic setting

• Published in: PLoS genetics Vol. 18; no. 2; p. e1010019
• Main Authors: Hernandez-Castro, Luis E, Villacís, Anita G, Jacobs, Arne, Cheaib, Bachar, Day, Casey C, Ocaña-Mayorga, Sofía, Yumiseva, Cesar A, Bacigalupo, Antonella, Andersson, Björn, Matthews, Louise, Landguth, Erin L, Costales, Jaime A, Llewellyn, Martin S, Grijalva, Mario J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04.02.2022; Public Library of Science (PLoS)
• Subjects: Adaptation; Adaptation, Biological - genetics; Animals; Arthropods; Biology and Life Sciences; Chagas disease; Chagas Disease - epidemiology; Chagas Disease - genetics; Disease control; Disease Vectors; Dispersal; Distribution; Domestication; Ecosystem; Ecuador - epidemiology; Embryogenesis; Epidemics; Gene Expression - genetics; Gene Expression Profiling - methods; Gene Flow; Genetic aspects; Genetic research; Genomes; Genomics; Habitats; Hemiptera; Insect Vectors - genetics; Insects as carriers of disease; Laboratories; Medicin och hälsovetenskap; Medicine and Health Sciences; Metagenomics - methods; Morphology; Natural history; Parasites; Polymorphism, Single Nucleotide - genetics; Population; Population Density; Population genetics; Population structure; Population studies; Research and Analysis Methods; Rhodnius - genetics; Rhodnius - pathogenicity; Risk factors; Saliva; Single-nucleotide polymorphism; Transcriptome - genetics; Tropical diseases; Trypanosoma cruzi - genetics; Vectors (Biology); West Nile virus; Ecuador; United States
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1010019

Accurate prediction of vectors dispersal, as well as identification of adaptations that allow blood-feeding vectors to thrive in built environments, are a basis for effective disease control. Here we adopted a landscape genomics approach to assay gene flow, possible local adaptation, and drivers of population structure in Rhodnius ecuadoriensis, an important vector of Chagas disease. We used a reduced-representation sequencing technique (2b-RADseq) to obtain 2,552 SNP markers across 272 R. ecuadoriensis samples from 25 collection sites in southern Ecuador. Evidence of high and directional gene flow between seven wild and domestic population pairs across our study site indicates insecticide-based control will be hindered by repeated re-infestation of houses from the forest. Preliminary genome scans across multiple population pairs revealed shared outlier loci potentially consistent with local adaptation to the domestic setting, which we mapped to genes involved with embryogenesis and saliva production. Landscape genomic models showed elevation is a key barrier to R. ecuadoriensis dispersal. Together our results shed early light on the genomic adaptation in triatomine vectors and facilitate vector control by predicting that spatially-targeted, proactive interventions would be more efficacious than current, reactive approaches.