In their latest publication in Nucleic Acids Research, Joep Joosten, Gijs Overheul, Ronald van Rij and Pascal Miesen, theme infectious diseases and global health, discover an intriguing interaction of a specific class of non-coding RNAs, called piRNAs, and viral RNA sequences in Aedes aegypti mosquitoes.
In their latest publication, Arthropod-borne viruses (arboviruses) including Dengue, Zika and Yellow fever virus are transmitted by Aedes aegypti mosquitoes. Yet, it is still poorly understood how the mosquito immune system controls virus infection and thereby affects virus transmission. An intriguing hypothesis in the field is that, similar to the antiviral CRISPR system in bacteria, endogenous viral sequences encoded in mosquito genomes give rise to small RNAs, so called piRNAs, that can induce degradation of viral RNA.
In their latest publication Joep Joosten and colleagues demonstrate that piRNAs derived from endogenous sources indeed target cognate viral sequences and they furthermore define the molecular machinery required for this activity. Along with several other recent publications by the group and other laboratories, these findings challenge the dogmatic view that the immune systems of insects are devoid of a heritable component. These discoveries have important implications for our understanding of mosquito immunity and virus transmission.