🦟 An antiviral in mosquitoes promotes dengue

Why are some mosquitoes more likely to transmit dengue than others?

A team of researchers has identified a genetic enzyme whose variations affect infection with this virus in Aedes aegypti, the species considered the primary vector of diseases. This discovery, published in the journal Nature Communications, reveals for the first time that a genetic factor is linked to the susceptibility of mosquitoes to dengue. This link could also be associated with their resistance to insecticides, paving the way for new antiviral strategies.


For decades, researchers have been trying to understand why some mosquitoes transmit the dengue virus more effectively than others. Studies had previously focused on genes linked to their classical immune system. A recent breakthrough by a team from the Laboratory of Evolutionary Genomics, Modeling, and Health (GEMS - CNRS / Institut Pasteur) highlights the importance of metabolic pathways, particularly enzymes from the cytochrome P450 family, in the interactions between mosquitoes and the virus.

To achieve these results, the researchers used several cutting-edge techniques. They first conducted infection tests to observe how the virus interacted with the mosquitoes. Then they analyzed gene expression using transcriptomics, a method that identifies active genes.

Using gene silencing and transgenesis tools, they then isolated a specific gene, CYP4G15, whose variations in the promoter strongly influence infection by the dengue virus in Aedes aegypti. This mosquito species is considered one of the most important disease vectors. This study thus marks a first in identifying natural genetic variations linked to susceptibility to this virus in these mosquitoes.

This discovery also suggests a possible mechanical link between virus susceptibility and insecticide resistance, as cytochrome P450 enzymes are known to promote mosquito resistance to chemical substances. It thus offers new perspectives for understanding interactions between mosquitoes and viruses and could lead to the development of new antiviral strategies, strengthening hopes for more effective control of dengue virus transmission.