Expression patterns of four npcRNAs corresponding to new 24-nt siRNA precursors. (Left panels) The gray boxed regions (above or below are Watson and Crick strands, respectively) indicate the npcRNA gene and transcript (black line) on the Arabidopsis genomic DNA coordinates. Small RNAs identified in public databases are indicated by small bands on both strands. The size of each siRNA is indicated in Supplemental Figure 2; npcRNAs spanning small RNA loci (following a color code). (Middle panels) Expression of these npcRNAs in different tissues (roots, stems, flowers, cauline leaves, and rosette leaves) determined by qRT-PCR. Relative expression levels were normalized with ACT2 (AT3G18780), and values for roots were arbitrarily fixed to 1; SDs are shown. (Right panels) Expression in flowers or seedlings of Col-0 and a rdr2/6 or ago7 mutant. Values for Col-0 were fixed to 1.
