(A) CDS- and 3′ UTR-located miRNA binding sites that induce mRNA degradation or are isolated in EIF2C2 CLIP experiments are under stronger selection pressure compared with miRNA-complementary sites that were not functional in these experiments; 2274 CDS- and 3956 3′ UTR-located sites that induce mRNA degradation are compared with 3513 CDS- and 3268 3′ UTR-located sites that do not induce mRNA degradation; 751 CDS- and 786 3′ UTR-located sites isolated in EIF2C2 CLIP experiments are compared with 1059 CDS- and 956 3′ UTR-located sites that do not induce EIF2C2 binding. (B) Scatter plot of the inferred probabilities that CDS- and 3′ UTR-located sites complementary to individual miRNAs are under selection. (Dashed red line) First principal component of the scatter.
