Fig. 2.

The locus IR71 as an example of siRNAs produced from single-stranded hairpin RNA precursors. (a) All individual siRNAs at IR71 that matched a unique position in the genome isolated from wild type (454 or MPSS), nrpd1a/1b (454), and rdr2 (MPSS). Vertical color bars, individual siRNAs; pink horizontal bars, the two arms of the inverted repeat. siRNAs shown above the inverted repeats matched the Watson strand, and those below matched the Crick strand of the genome. (b) Examples of siRNAs produced from the imperfectly matched regions (red dots) of the predicted single-stranded hairpin of IR71. Horizontal bars, siRNAs that match the left (above the alignment) or right arm (below the alignment).