Invasive Asian tiger mosquito Aedes albopictus harbors reduced gut bacterial microbiota and genetic diversity compared to autochthonous relatives

The Asian tiger mosquito Aedes albopictus constitutes one of the most preoccupying pathogen vector species of the 21st century. Originated from South and East Asia, it has invaded a high range of eco-climatic regions worldwide. In the light of the holobiont theory, insect-associated microbiota is recognized to play a significant role in host biology. Following this observation, we hypothesized that bacterial microbiota could be parts of the puzzle of understanding the driving forces of Ae. albopictus adaptation and subsequent invasiveness. In this context, we performed a comparative analysis of genetic (11 microsatellite markers and COI haplotype) and bacterial diversity (high-throughput sequencing of 16S rRNA gene) of field-caught mosquitoes from Vietnamese autochthonous and French recently introduced populations. In whole individuals body, bacterial microbiota was largely dominated by Wolbachia pipientis with a conserved proportion of both wAlbA and wAlbB clades over sites. However, analysis of gut microbiota revealed a greater bacterial diversity in which Dysgonomonas was the most prevalent genus. Moreover, a reduced bacterial and genetic diversity was evidenced in French populations in comparison to Vietnamese autochthonous ones. This ecological genomics integrated approach also raises questions of the role of bacterial microbiota in the tiger mosquito biology, including vector competence, and ecology.