Cooler temperatures destabilize RNA interference and increase susceptibility of disease vector mosquitoes to viral infection

The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus), exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery. Total small RNAs (miRNAs, siRNAs, piRNAs, etc.) were isolated and sequenced from the heads of sensor strain Aedes aegypti mosquitoes, or from the whole bodies of CHIKV-infected Aedes albopictus mosquitoes 8 hours post infection. Mosquitoes were grown at 18C or 28C in replicates of 1 (Ae. aegypti) or 3 (Ae. albopictus).