Fitness costs in the presence and absence of insecticide use explains abundance of two common < i > Aedes aegypti kdr < /i > resistance alleles found in the Americas

In this study, we conducted a population cage experiment to evaluate changes in the allele and genotype frequencies of the410L+1016I+1534C allele by crossing two congenic strains; one carrying the410L+1016I+1534C and another with the 1534C allele. Changes in allele frequencies were measured over 10 generations in the absence of insecticide exposure. We also applied one cycle of selection with deltamethrin at F9 to evaluate the changes in allele and genotype frequencies. Our findings indicate that fitness costs were higher with the410L+1016I+1534C allele, relative to the1534C allele, in the absence of deltamethrin exposure, but that the410L+1016I+1534C allele provides a stronger advantage when exposed to deltamethrin relative to the1534C allele. Changes in genotype frequencies were not in Hardy-Weinberg equilibrium and could not be explained by drift. Our results suggest the diametrically opposed fitness costs in the presence and absence of insecticides is a reason for the variations in frequencies between the410L+1016I+1534C and1534C alleles in field populations.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research