The canonical siRNA-processing pathway is not involved in the regulation of SNORD44 sdRNAs.

<p><i>A–D</i> HeLa cells were transfected with control or Drosha-targeting siRNA and incubated for 48 hours. Cells were fixed and stained for Drosha (<i>A</i>) or DGCR8 (<i>B</i>), and counterstained for DNA. Merged images are shown. Scale bar, 10 µm. (<i>C, D</i>) Image quantifications for (<i>C</i>) Drosha and (<i>D</i>) DCGR8. Mean normalized fold intensity is shown. Error bars, SD. <i>E</i> Nuclear (containing nucleoli) and cytoplasmic fractions were prepared of the cells described in A, and RNA was isolated. Northern hybridization was conducted using the SNORD44 5′ probe. Signal intensities for 120 nt and sdRNAs were quantified and normalized against the mature SNORD44. <i>F</i> HCT116 and HCT116 Dicer −/− cells were subjected to subcellular fractionation, RNA was isolated and Northern hybridization was conducted using the SNORD44 5′ probe. Signal intensities for sdRNAs normalized to mature SNORD44 are provided below. hY1 probe was used as control.