The global burden of mosquito-transmitted diseases, including malaria, dengue, West Nile, Zika, Usutu, and yellow fever, continues to increase, posing a significant public health threat worldwide. With the rise of insecticide resistance and the absence of an effective vaccine, new strategies are emerging that focus on the mosquito's microbiota. Among these, the endosymbiotic and maternally-inherited bacteria Wolbachia, which can selfishly manipulate the reproduction of their host and interfere with viral pathogens, stands out. However, despite its promise, the genomic variability of Wolbachia and its mobile genetic elements along with its impact on pathogen blocking, in interaction with other symbiotic life, particularly in naturally infected vectors like Culex mosquitoes, remains poorly understood. Leveraging state-of-the-art Ecogenomic tools, the RosaLind project aims to reconstruct bacterial genomes from Culex specimens collected around the world, one mosquito organ at a time. The obtention of novel Wolbachia genomes at the global scale aims to investigate Wolbachia's genomic variability and examine how it contributes to distinct phenotypes of density and protection against viruses. Simultaneously, the project aims to identify and analyse other symbiotic genomes, notably in the midgut of mosquitoes, that could be exploited to fight vector-borne diseases. Moreover, it is expected these newly reconstructed symbiotic genomes serve as reference genomes to study the complex interaction between symbionts and arboviruses through differential expression analyses in infection conditions. Lastly, an important objective of the project is to explore the diversity, biogeography, and transformation capacity of the recently discovered Wolbachia plasmid element (called pWCP for plasmid of Wolbachia in Culex pipiens). While Wolbachia remains not amenable to genetic manipulation, these findings could pave the way for the development of novel vector biocontrol strategies.
