Genomic and microscopic evidence of stable high density and maternally inherited<i>Wolbachia</i>infections in<i>Anopheles</i>mosquitoes

Abstract

Wolbachia, a widespread bacterium that can reduce pathogen transmission in mosquitoes, has been detected within populations ofAnopheles (An.)malaria vectors. In theAn. gambiaecomplex, the primary vectors in Sub-Saharan Africa,Wolbachiastrains are at low density and infection frequencies in wild populations. PCR-independent evidence is required to determine whetherWolbachiastrains are true endosymbionts inAnophelesgiven most studies to date have used nested-PCR to identify strains. Here we report high-density strains found in geographically diverse populations ofAn. mouchetiandAn.demeilloni. Fluorescentin situhybridization localized a heavy infection in the ovaries ofAn. mouchetiand maternal transmission was observed. Genome sequencing of both strains obtained genome depths and coverages comparable to other known infections. Notably, homologs of cytoplasmic incompatibility factor (cif) genes were present indicating these strains possess the capacity to induce the phenotype cytoplasmic incompatibility which allowsWolbachiato spread through populations. The characteristics of these two strains suggest they are ideal candidates forWolbachiabiocontrol strategies inAnopheles.