Novel miRNAs identified from Venn analysis of rdr2 sequences. Small RNAs were selected for validation by RNA gel blots, as described in the text. Low molecular weight RNA isolated from inflorescence tissues was probed with labeled oligonucleotides. The lanes in the blots include the following samples: wild type, rdr2, rdr6, dcl1–7, and dcl2/3/4. The normalized abundance level from the MPSS data for rdr2 and wild type is listed to the right of the identifier for each small RNA. The reason for the apparent increases in abundance in rdr2 vs. wild type in the blots is not clear; approximately equal amounts of RNA were loaded. It does not appear to be due to RDR2-dependent small RNAs in the 5′ flanking regions, although for miR775, the most extreme case, there is an overlapping small RNA that is largely RDR2-dependent that might interfere with miR775 production in wild type.
