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

<jats:title>Abstract</jats:title><jats:p><jats:italic>Wolbachia</jats:italic>, a widespread bacterium that can reduce pathogen transmission in mosquitoes, has been detected within populations of <jats:italic>Anopheles (An.)</jats:italic> malaria vectors. In the <jats:italic>An. gambiae</jats:italic> complex, the primary vectors in Sub-Saharan Africa, <jats:italic>Wolbachia</jats:italic> strains are at low density and infection frequencies in wild populations. PCR-independent evidence is required to determine whether <jats:italic>Wolbachia</jats:italic> strains are true endosymbionts in <jats:italic>Anopheles</jats:italic> given most studies to date have used nested-PCR to identify strains. Here we report high-density strains found in geographically diverse populations of <jats:italic>An. moucheti</jats:italic> and <jats:italic>An</jats:italic>. <jats:italic>demeilloni</jats:italic>. Fluorescent <jats:italic>in situ</jats:italic> hybridization localized a heavy infection in the ovaries of <jats:italic>An. moucheti</jats:italic> and 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 (<jats:italic>cif</jats:italic>) genes were present indicating these strains possess the capacity to induce the phenotype cytoplasmic incompatibility which allows <jats:italic>Wolbachia</jats:italic> to spread through populations. The characteristics of these two strains suggest they are ideal candidates for <jats:italic>Wolbachia</jats:italic> biocontrol strategies in <jats:italic>Anopheles</jats:italic>.</jats:p>