B) Silver stained gel shows loading control. C) RNAi component transcripts are modulated during DENV2 infection. Relative changes in DENV2-infected HWE midgut transcript levels detected by qRT-PCR. Significant changes over controls are marked with asterisks (p ≤ 0.05, Mann-Whitney U test); error bars depict standard error of three biological replicates. Pools of 5 midguts were used in each replicate. Relative transcript levels were calculated using the delta-delta Ct method, using ribosomal protein S7 as a reference standard. Enrichment is relative to that of un-infected blood-fed control mosquitoes. D) Western blot of immunoprecipitated products (IP) from
pools of 20 DENV2-infected RexD mosquitoes. ‘UN’, Un-infected blood-fed control mosquitoes collected at 2 dpf
(days post-feeding), probed with non-immune serum; ‘U’, un-infected blood-fed mosquito Ago2 antibody PI3K inhibitor IP; ‘DN’, Dengue/blood-fed mosquitoes collected at 2 dpi, probed with non-immune serum; ‘D’, Dengue/blood-fed mosquito Ago2 antibody IP. Size markers show approximate molecular weight of bands shown. To determine whether Ago2, Dicer-2 or TSN expression levels are modulated during DENV2 infection, we used quantitative real-time PCR to measure component mRNA levels in midguts at the initial site of infection. Dicer-2 and Ago2 transcript levels were significantly enriched in DENV2-infected midguts over un-infected blood-fed controls at 1 dpi (Figure 1C). At 2, 3, check details and 4 dpi, variability in Ago2 and Dicer-2 transcript levels increases, thereby negating significant differences
compared to un-infected controls. By 9 dpi, transcript levels are indistinguishable from those of un-infected controls (data not shown). In contrast, TSN transcriptional co-factor levels were depleted at 1 dpi and enriched at 2 and 3 dpi. Immunoprecipitation (IP) of Ago2 complexes from un-infected blood-fed and DENV2-infected mosquitoes (Figure 1D) and subsequent cloning revealed sRNAs of 12 to 21 nts. The sRNA sequences prepared from the IP-cloning were not among those of the over- or under-represented host sRNAs (data not shown). Multiple bands are present in the immunoblot, and there is little difference Cell Penetrating Peptide in the intensity of Ago2 bands when DENV2-infected and blood-fed controls are compared. A faint Ago2 band at 132 kDa is present in un-infected mosquito IPs and not in DENV2-infected mosquitoes. Deep selleck compound sequencing reveals virus-derived usRNAs, siRNAs, and piRNAs Pools of twenty mosquitoes from three biological replicates each of virus-infected and un-infected blood fed controls were collected at 2, 4, and 9 dpi, for a total of eighteen libraries. sRNAs up to about 40 nts in length were isolated from total RNA and deep sequenced using sequencing-by-ligation. Library sequences were aligned sequentially to the Ae. aegypti published transcriptome, (V.1.2, Vectorbase.org, [26, 27] and DENV2 viral genome (Genbank accession number M20558).