Genetic variation in the odorant receptor gene OR4 and bit habits in natural populations of Aedes aegypti from Antioquia department, Colombia.

Abstract

It has been determined factors that make humans more attractive to mosquitoes and which strategies they use to detect a potential host. Preferential differences for human/non-human hosts are related to variations in odorant receptors (OR) genes in the Aedes aegypti mosquitoes. This study use sequencing to establish the genetic variation in the odor receptor OR4 in 900 mosquitoes from different regions of Antioquia. A behavioral test using an olfactometer was also made to stablish the relationship of these variation with the attraction on different human hosts. The analysis in the attraction and OR4 variants did not show significant differences in the arrival rate among different human hosts. No significant differences in the description of OR4 variants between populations and between hosts, show that this gene is homogeneously distributed. The analysis showed a high genetic population diversity, measured as polymorphism and heterozygosity. This may be due to a few high frequency haplotypes in all the populations examined, suggesting a model of high gene flow between populations and/or selection in favor of these variants in all populations. Other low-frequency variants, many of which are population-specific, reflect the effect of genetic drift probably due to stochastic changes in the size of natural mosquito populations.