(
A) Pie chart reflecting the relative proportions of reads for the indicated miRNA families observed when sequencing small RNAs from HeLa cells. Relative miRNA levels were quantified as described previously (
Denzler et al., 2014). (
B and
C) Cumulative distributions of fold changes for mRNAs with at least one canonical 7–8 nt 3′-UTR site to the indicated miRNA family in the compendium of 74 sRNA transfection datasets, either before (
B) or after (
C) normalization. p values were computed using a one-sided Wilcoxon rank-sum test, comparing each of the site-containing distributions to the no-site distribution. This test was a more stringent alternative to the K–S test, which led to highly significant p values for very slight differences, due to the large number of mRNAs in each distribution. To account for multiple hypotheses, an appropriate Bonferroni-corrected significance threshold would be p < 0.005, which was not achieved for most comparisons in panel (
C).