Development of an enhanced RNAi delivery system for gene silencing in blacklegged ticks (Ixodes scapularis)

Introducing inhibitory RNA (RNAi) into ticks is a powerful reverse genetic tool that is useful for characterizing molecular processes controlling tick salivary gland secretions. However, to accurately quantify the degree of gene knockdown, or expression of differentially expressed genes for that matter, reliable and accurate RT-qPCR methods rely on selecting stable reference genes for normalization. The goal of this study is to evaluate candidate reference genes for expression stability across a range of feeding time points in blood feeding nymphal blacklegged ticks (Ixodes scapularis,) and to use this optimized normalization strategy to assess differential gene expression of two sulfotransferase enzymes (Ixosc SULT1), and (Ixosc SULT2) during nymphal feeding. Ixosc SULT1 and Ixosc SULT2 were determined to be differentially expressed with a decreased expression across the nymphal blood feeding process. Elucidating the expression pattern of these and studying them using RNAi may provide further insight into regulatory mechanisms controlling tick feeding