Biology subjects

Raquin, V.

Publications and source records attributed to Raquin, V..

3 recordsLinked to original sources

bioRxiv2024

A major entomoparasite interferes with Chikungunya transmission by Aedes albopictus

The Asian tiger mosquito, Aedes albopictus, spreads diseases like Chikungunya and has caused outbreaks worldwide. Studies show that mosquitoes-associated microbes can affect how well they spread diseases. One of those microbes, the parasite As. taiwanensis, is common in older mosquito populations but rare in newer ones. We found that this parasite slows down the spread of Chikungunya within the mosquito and decreases its transmission rate by half. Unparasitized mosquitoes spread the virus more easily, suggesting that changes in mosquito microbes could impact disease outbreaks and public health.

microbiology↗

bioRxiv2022

Variation in diet and microbial exposure shape the performance of the Asian tiger mosquito, Aedes albopictus

Along their life cycle, mosquitoes colonize different ecological niches with various microorganisms and diet sources that likely modulate their performance (i.e. a set of mosquito fitness-related traits). However, which ecological parameters and how their variations modulate mosquito performance is not completely understood. In this study, we used Ae. albopictus surface-sterilized eggs re-associated or not to conventional bacterial microbiota upon a range of diet concentrations and addressed the impact of microbial inoculum and diet concentration variation on several mosquito performance traits. Results showed that mosquito juvenile survival depends on the interaction between bacterial inoculum load and diet concentration in the breeding water. Exposure to bacteria in rearing water shorten larval development time although it impacted larvae survival in an inoculum and diet concentration-dependent manner. Bacterial composition of larval rearing water was mainly structured by the bacterial inoculum concentration, with some Operational Taxonomic Units abundances correlating with larval traits. Ae. albopictus survival, development and bacterial community patterns upon gradients of diet and bacterial inoculum illustrated the complex impact of diet-microbiota interaction on mosquito performance. These findings argue the importance of deciphering host-microbe-environment interactions and open promising perspectives to improve Ae. albopictus control measures in the field. IMPORTANCEMicrobiota is increasingly recognized as a driving force of metazoan biology, impacting diverse traits including nutrition, behaviour or reproduction. The microbial impact on host nutrition is among the most studied host-microbe interactions although it remains poorly understood in arthropod vectors like mosquitoes. Here, we manipulated mosquito microbiota using gnotobiology to decipher the impact of bacteria and diet on the Asian tiger mosquito, Ae. albopictus. These results are key to understand the link between diet and bacteria concentration on juvenile mosquitoes as well as carry-over effects in adults. They unveil some specific aspects of mosquito-bacteria interactions while opening interesting avenues for vector management of this vector of arboviruses.

microbiology↗

bioRxiv2019

Tudor-SN promotes early replication of dengue virus in the Aedes aegypti midgut

Diseases caused by mosquito-borne viruses have been on the rise for the last decades, despite the implementation of vector control methods primarily based on insecticides. An alternative control method currently in development is the use of lab-engineered mosquitoes that are incapable to carry viruses. This has stimulated efforts to identify optimal target genes that are naturally involved in mosquito antiviral defenses or required for viral replication. Although several antiviral immune pathways such as RNA interference (RNAi) have been previously characterized in mosquitoes, the genes that prevent or promote early viral replication in the midgut remain elusive. Here, we investigated the role of a member of the Tudor protein family, Tudor-SN, upon dengue virus infection in the mosquito Aedes aegypti. Tudor-SN expression was upregulated early after dengue virus infection and was subsequently positively correlated with viral loads in the midgut. Using RNAi-mediated knockdown, we showed that the loss of Tudor-SN reduced dengue virus replication in the Ae. aegypti derived cell line Aag2 and in the midgut of Ae. aegypti females in vivo. Using immunofluorescence assays, we found that Tudor-SN localizes to the nucleolus in both Ae. aegypti and Aedes albopictus cells. Finally, we used a reporter assay to demonstrate that Tudor-SN was not required for RNAi function in vivo. Collectively, these results define a novel proviral role for Tudor-SN upon early dengue virus infection of the Ae. aegypti midgut.

microbiology↗