Figure 3.

Frequency of extra 5' nucleotides. Several small Arabidopsis thaliana RNA datasets were analyzed for the occurrence of miRNAs with extra 5' nucleotides. From these datasets, 61% of the A. thaliana miRNAs listed in miRBase had no significant occurrence of extra nucleotides, 20% of the annotated miRNAs were not observed in the datasets at all, and 19% of miRNA had a significant proportion of either one (+1 MIR) or two (+2 MIR) nucleotides.