RNA-Seq reveals why mosquitoes don’t suffer from the infections they pass on

Researchers from CSIRO Health and Biosecurity have published findings that start to explain how mosquitoes respond to viral infections. Using an RNA-sequencing approach, they identified a number of genes from multiple cellular pathways that play integral roles in protecting mosquitoes from the viruses they carry.

Previously, the researchers had identified a new protein, Vago, that was shown to restrict the spread of viral infection in mosquitoes. Most recently, they have shown that a virus increases production of a mosquito gene, Cullin4, which shuts down the immune response of mosquitoes by blocking the action of Vago. This allows the virus to multiply in mosquitoes and be transmitted to the next person.

This is the first demonstration at the molecular level that such an immune evasion mechanism exists in mosquitoes or any other insect. These results provide new insights into how virus reproduces in mosquitoes. It has also provided us with a large dataset of mosquito genes, which play a role during the infection process.

New approaches are needed to reduce the health burden of mosquito-borne diseases. These findings suggest it may be possible to reduce a mosquito’s capacity to transmit viruses by manipulating its immune system.