Figure 5.

Reads from both arms of a hairpin, and sequential reads from the same arm. (A) Fraction and abundance of miRNA reads from each miRNA hairpin. To calculate the fraction, the miRNA reads were divided by the total number of miRNA and miRNA* reads, considering on each arm only the major 5′ terminus. The dashed lines indicate the median fraction of miRNA reads and the median number of miRNA reads for conserved (red) and nonconserved (blue) miRNAs. (B) Switching of the dominant arm in different samples. For each sample, the fold enrichment of miRNA reads produced from the 5′ arm over those produced from the 3′ arm and vice versa was calculated. Shown are results for nonrepetitive miRNAs that switch dominant arms, with at least a fivefold differential between two samples. The samples are color-coded (key), and an asterisk indicates samples with statistically significant enrichment of miRNAs produced from one arm over the other (P < 0.05, χ² test). (C) Sequential Dicer cleavage. Predicted secondary structure of mmu-mir-3102 pre-miRNA (Hofacker et al. 1994).