FIGURE 8.

RDRC subunits differentially impact 23–24-nt sRNA accumulation in vivo. (A) Total RNA isolated from starving (St) or growing (V) wild-type cells or cells expressing Rdr1–D1004A was size-enriched for small RNA, resolved by denaturing gel electrophoresis and stained directly. Starved or growing cell cultures were treated with 0.1 μg/mL CdCl₂ or 1 μg/mL CdCl₂, respectively, for the times indicated to induce catalytic-dead Rdr1 overexpression. Wild-type cells were similarly treated with CdCl₂ as a control. (B) Aliquots of enriched sRNA from growing wild-type or gene-knockout cells were used for direct staining (top panel) or Northern blots. Representative sRNA expression results are shown for an individual sRNA (sRNA2) or 14 other sRNAs (sRNA mix) of known sequence used for Northern blot assays in previous work (Lee and Collins 2006). A summary of sRNA phenotypes is also provided.