Size distribution and frequency of 5' base of overlapping small RNAs (small RNAs at least 24 nt long, overlapping pairs on opposite strands) for all combined Ae. aegypti libraries (A) and the D. melanogaster library (B). The length of overlap is shown on the horizontal axes. Indicated above each axis is the number of possible overlapping pairs of small RNAs (individual small RNA sequences may be involved in multiple pairs) with specified overlap size. Indicated below each axis is the relative frequency of the 5' base identity for sequences involved in overlapping pairs. The color code for bases is indicated in the center box.