Mosquitoes, particularly Aedes albopictus, are notorious vectors of deadly pathogens, including arboviruses, which cause thousands of deaths annually. With limited antiviral treatments and growing concerns about the ecological impact of chemical insecticides, species-specific strategies like RNA interference (RNAi) are gaining traction. RNAi, a natural process in eukaryotes, offers a promising approach to control these vectors by targeting specific genes. However, its effectiveness in Ae. albopictus has been inconsistent, often due to degradation by nucleases. This study aimed to address these challenges and improve RNAi-based control of Ae. albopictus.
Researchers identified target genes, designed double-stranded RNAs (dsRNAs), and tested their efficacy in Ae. albopictus cells and larvae. While all target genes were successfully silenced in cells, only one dsRNA targeting the inhibitor of apoptosis (IAP) gene significantly reduced cell viability. However, none of the dsRNAs induced significant larval mortality, likely due to rapid degradation by larval gut extracts.
To investigate this further, the researchers analyzed dsRNA complex size, oral uptake, and degradation by larval gut extracts. They identified and characterized two putative dsRNases in Ae. albopictus, which were highly expressed in larval guts. Transfection reagents (TRs) were tested for their ability to protect dsRNA from degradation, with some success.
The study concludes that while RNAi can effectively silence target genes in cells and larval gut tissue, achieving lethal effects in larvae requires addressing multiple biological hurdles, including improving dsRNA stability and delivery systems. The findings provide valuable insights into the challenges of RNAi-based control of Ae. albopictus and highlight the need for further research to optimize this promising approach.