Nosemosis control in European honey bees Apis mellifera by silencing the gene encoding Nosema ceranae polar tube protein 3

RNA interference (RNAi) is a post-transcriptional gene silencing mechanism triggered by double-stranded RNA (dsRNA) that is homologous in sequence to the silenced gene and is conserved in a wide range of eukaryotic organisms. The RNAi mechanism has provided unique opportunities in combating honey bee diseases caused by various parasites and pathogens. is a microsporidian parasite of European honey bees, , and has been associated with honey bee colony losses in some regions of the world. Here we explored the possibility of silencing the expression of a putative virulence factor encoding polar tube protein 3 ( ) which is involved in host cell invasion as a therapeutic strategy for controlling parasites in honey bees. Our studies showed that the oral ingestion of a dsRNA corresponding to the sequences of could effectively suppress the expression of the gene in infected bees and reduce load. In addition to the knockdown of gene expression, ingestion of -dsRNA also led to improved innate immunity in bees infected with along with an improvement in physiological performance and lifespan compared to untreated control bees. These results strongly suggest that RNAi-based therapeutics hold real promise for the effective treatment of honey bee diseases in the future and warrant further investigation.