Genetic Polymorphism and Phylogenetics of Aedes aegypti from Sudan Based on ND4 Mitochondrial Gene Variations

SIMPLE SUMMARY: Arthropod-borne viruses (arboviruses) place a heavy social and economic burden on society by infecting millions of people and causing widespread animal and human sickness. These viruses are often transmitted to their vertebrate hosts by arthropod vectors. The mosquito Aedes aegypti is thought to be the principal vector for arboviral diseases such as dengue, yellow fever, zika, chikungunya, and others. Aedes aegypti, which is believed to have its origins in Africa, is known to have two subspecies or forms that are differentiated from one another in terms of behavior, transmitting power, and dispersal. The study of genetic structure and variations among different forms/subspecies of disease vectors sheds important light on their biology, behavior, genetic mixing, and capacity to spread disease. To better understand the genetic polymorphism of the two forms of Aedes aegypti, this study looked at various populations of the mosquito in different locations in Sudan. The findings revealed that the genetic variance between the two subspecies was insignificant, and they shared some components in the gene/marker we used in the study. This information will be required to improve the control strategies against the Aedes aegypti vector in the area. ABSTRACT: This study investigated the genetic differences between Aedes aegypti subspecies (Aedes aegypti aegypti (Aaa) and Aedes aegypti formosus (Aaf)) from Sudan using the NADH dehydrogenase subunit 4 (ND4) mitochondrial gene marker. Nineteen distinct haplotypes of the ND4 were identified in female Aedes aegypti mosquitoes from the study sites. The phylogenetic relationship of the 19 ND4 haplotypes was demonstrated in a median-joining haplotype network tree with Aaa and Aaf populations found to share three haplotypes. The genetic variance (Pairwise F(ST) values) was estimated and found to range from 0.000 to 0.811. Isolation by distance test revealed that geographical distance was correlated to genetic variation (coefficient value (r) = 0.43). The Polar maximum likelihood tree showed the phylogenetic relationship of 91 female Aaa and Aaf from the study sites, with most of the Aaf haplotypes clustered in one group while most of the Aaa haplotypes gathered in another group, but there was an admixture of the subspecies in both clusters, especially the Aaa cluster. The Spatial Analysis of Molecular Variance (SAMOVA) test revealed that the eight populations clustered into two phylogeographic groups/clusters of the two subspecies populations. The 2 Aedes aegypti subspecies seemed not to be totally separated geographically with gene flow among the populations.