Country-scale diversity, spatial genetic structure, and mitochondrial demographic history of Aedes aegypti populations in Colombia.

Abstract

Aedes aegypti is the primary urban vector of major human arboviruses worldwide, yet the spatial genetic structure and demographic history of Colombian populations remain incompletely understood. Here, we analyzed mitochondrial cytochrome c oxidase subunit I (COX1) sequences from Colombian populations sampled across a broad geographic and temporal range to evaluate genetic diversity, haplotype distribution, spatial-temporal structure, and mitochondrial demographic history. The dataset combined publicly available COX1 records with 394 newly generated sequences from Colombian specimens, yielding 717 entries from the Caribbean, Andean, Orinoco, and Amazonian regions of Colombia, and was analyzed using population genetic, ordination, constrained spatial, and demographic inference approaches. Colombian COX1 diversity was mainly structured into two broad mitochondrial genetic clusters rather than by sampling locality, department, or collection year, suggesting the persistence of maternal lineages together with spatial mixing likely influenced by human-mediated dispersal and urban adaptation. Human population density and built-up intensity partially explained mitochondrial genetic structure, but this association varied through time, indicating that urbanization interacts with regional demographic heterogeneity and local habitat configuration. Demographic history analyses suggested temporal variation in mitochondrial effective population size, including an older increase followed by reduction and relative stabilization toward recent generations, rather than continuous demographic expansion. Climate-associated analyses further suggested that temperature, particularly minimum temperature, may contribute to mitochondrial demographic variation, although this relationship should be interpreted as correlative. Overall, Colombian Ae. aegypti populations appear to be shaped by historical maternal-lineage structure, urbanization-associated spatial heterogeneity, eco-regional demographic variation, and climatic context. This country-scale mitochondrial baseline can help prioritize regions for genomic, entomological, and epidemiological surveillance and guide future investigations of mosquito dispersal and population connectivity relevant to vector management in Colombia.