Genome-wide variant analysis reveals divergent genetic signatures inAedes aegyptiand its morphological variantAedes aegyptivar.luciensis

Abstract

In this study, we analysed the genetic diversity between the two morphotypes of Aedes aegypti by identifying and characterizing genomic variants from low-coverage resequencing data. Four samples from each morphotype were sequenced, and high-quality variants were identified. Variants from the four samples of each morphotype were combined, considering only those present in all samples (missing variants were excluded). This resulted in 7,181 variants in the normal type and 4,513 in the variant type, with only 1,180 shared variants identified between the two morphotypes. Most variants in both types were found in non-coding regions. Chromosomal distribution showed comparable variant frequencies between morphotypes, with similar transition/transversion ratios. The neighbor-joining tree indicated distinct genetic clusters for each morphotype, likely driven by different demographic histories. We have not obtained much data on variations in the coding regions, probably due to low sequencing coverage. However, the significant genetic differentiation between the two morphotypes indicates important evolutionary processes at play. Understanding these variations is crucial from an epidemiological perspective, as they may lead to differences in vector competence for pathogens, potentially affecting transmission dynamics and disease risk.