Neofunctionalization driven by positive selection led to the retention of the loqs2 gene encoding an Aedes specific dsRNA binding protein.

Background: Mosquito borne viruses, such as dengue, Zika, yellow fever and Chikungunya, cause millions of infections every year. These viruses are mostly transmitted by two urban-adapted mosquito species, Aedes aegypti and Aedes albopictus. Although mechanistic understanding remains largely unknown, Aedes mosquitoes may have unique adaptations that lower the impact of viral infection.

Control of dengue virus in the midgut of Aedes aegypti by ectopic expression of the dsRNA-binding protein Loqs2.

Dengue virus (DENV) is an arbovirus transmitted to humans by Aedes mosquitoes. In the insect vector, the small interfering RNA (siRNA) pathway is an important antiviral mechanism against DENV. However, it remains unclear when and where the siRNA pathway acts during the virus cycle.