Aedes mosquitoes, like the Asian tiger mosquito (Aedes albopictus), spread viruses such as dengue and Zika in the Global South. Due to climate change and global travel, Aedes albopictus is now found throughout Europe, posing potential health risks. Surprisingly, these mosquitoes do not get sick from the viruses they carry. This is because they have a defense system that uses small-RNA molecules to fight infections. One type of small-RNAs, called piRNAs, protects their genetic material, controls gene expression, and fights viruses. In this doctoral thesis, we discovered that a protein called Piwi5 is essential for producing virus-targeting piRNAs. A similar protein, Piwi6, protects mosquito DNA from harmful “jumping genes”. We also found that mosquito salivary glands, which produce the saliva by which viruses are transmitted to humans during a mosquito bite, produce many virus-targeting piRNAs. Understanding this small-RNA-based defense system may aid developing new ways to stop mosquitoes from spreading diseases.
Ezgi Taşköprü, born in Istanbul, studied Molecular Biology & Genetics at Boğaziçi University. She moved to the Netherlands for her master studies at uu77 and stayed in Nijmegen to pursue her PhD on the piRNA pathway in Aedes mosquitoes in Prof. Dr. Ronald van Rij’s team. She is now a postdoctoral researcher in Molecular Biology Department at uu77.