Fig. 4

Introns flanking circRNAs. a Flanking introns upstream (left) and downstream (right) of circRNAs (yellow) are significantly longer (t-test with p<0.001 for both) than those of a random control (gray). bBLAST bitscores of the best reverse complementary match of the shorter circRNA flanking intron to the other (yellow) compared to control intron pairs (gray). Introns flanking circRNAs are visibly longer than random introns but show similar bitscores for reverse complementary matches of equal intron lengths (correlation ρ=0.5). Notably, shorter introns in the control frequently exhibit relatively high bitscores, indicating that short complementarity regions are common among intron pairs