Inducing RNA interference in the arbovirus vector, Culicoides sonorensis

Area of Science:

• Entomology
• Molecular Biology
• Vector-borne Diseases

Background:

• Biting midges (Culicoides spp.) are significant vectors of economically impactful arboviruses globally.
• Research on Culicoides vectors is limited by a lack of genomic data and molecular tools like RNA interference (RNAi).

Purpose of the Study:

• To establish RNA interference (RNAi) as a functional research tool in adult Culicoides sonorensis.
• To investigate the feasibility of using dsRNA injection for gene knockdown in adult midges.

Main Methods:

• Transcriptome analysis to identify RNAi pathway components.
• Injection of double-stranded RNA (dsRNA) targeting green fluorescent protein (dsGFP) as a control.
• Injection of dsRNA targeting the Culicoides sonorensis inhibitor of apoptosis protein 1 (CsIAP1) gene.
• Monitoring of transcript levels and median survival rates post-injection.

Main Results:

• Successful establishment of RNAi in adult C. sonorensis.
• Injection of dsRNA targeting CsIAP1 led to a 40% reduction in transcript levels.
• CsIAP1 knockdown resulted in a 73% decrease in median survival compared to controls.
• Control dsGFP injection did not significantly impact survival, supporting virus transmission models.

Conclusions:

• RNAi is a feasible and powerful tool for functional genomics in adult C. sonorensis.
• The conserved function of inhibitor of apoptosis protein 1 (IAP1) was confirmed in this species.
• This advancement will significantly accelerate research into the vector competence of C. sonorensis.