AUTHOR=Gomard Yann , Hafsia Sarah , Lebon Cyrille , Rabarison Patrick , Idaroussi Ambdoul-bar , Yssouf Amina , Boussès Philippe , Mavingui Patrick , Atyame Célestine 

TITLE=Genetic diversity of endosymbiotic bacteria Wolbachia infecting two mosquito species of the genus Eretmapodites occurring in sympatry in the Comoros archipelago

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1343917

DOI=10.3389/fmicb.2024.1343917

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>The influence of <italic>Wolbachia</italic> on mosquito reproduction and vector competence has led to renewed interest in studying the genetic diversity of these bacteria and the phenotypes they induced in mosquito vectors. In this study, we focused on two species of <italic>Eretmapodites</italic>, namely <italic>Eretmapodites quinquevittatus</italic> and <italic>Eretmapodites subsimplicipes</italic>, from three islands in the Comoros archipelago (in the Southwestern Indian Ocean).</p></sec><sec><title>Methods</title><p>Using the <italic>COI</italic> gene, we examined the mitochondrial genetic diversity of 879 <italic>Eretmapodites</italic> individuals from 54 sites. Additionally, we investigated the presence and genetic diversity of <italic>Wolbachia</italic> using the <italic>wsp</italic> marker and the diversity of five housekeeping genes commonly used for genotyping through Multiple Locus Sequence Typing (MLST).</p></sec><sec><title>Results and discussion</title><p>Overall, <italic>Er. quinquevittatus</italic> was the most abundant species in the three surveyed islands and both mosquito species occurred in sympatry in most of the investigated sites. We detected a higher mitochondrial genetic diversity in <italic>Er. quinquevittatus</italic> with 35 reported haplotypes (<italic>N</italic> = 615 specimens, <italic>Hd</italic> = 0.481 and π = 0.002) while 13 haplotypes were found in <italic>Er. subsimplicipes</italic> (<italic>N</italic> = 205 specimens, <italic>Hd</italic> = 0.338 and π = 0.001), this difference is likely due to the bias in sampling size between the two species. We report for the first time the presence of <italic>Wolbachia</italic> in these two <italic>Eretmapodites</italic> species. The prevalence of <italic>Wolbachia</italic> infection varied significantly between species, with a low prevalence recorded in <italic>Er. quinquevittatus</italic> (0.8%, <italic>N</italic> = 5/627) while infection was close to fixation in <italic>Er. subsimplicipes</italic> (87.7%, <italic>N</italic> = 221/252). Both male and female individuals of the two mosquito species appeared to be infected. The analysis of MLST genes revealed the presence of two <italic>Wolbachia</italic> strains corresponding to two new strain types (STs) within the supergroups A and B, which have been named <italic>w</italic>EretA and <italic>w</italic>EretB. These strains were found as mono-infections and are closely related, phylogenetically, to <italic>Wolbachia</italic> strains previously reported in <italic>Drosophila</italic> species. Finally, we demonstrate that maternal transmission of <italic>Wolbachia</italic> is imperfect in <italic>Er. subsimplicipes</italic>, which could explain the presence of a minority of uninfected individuals in the field.</p></sec>