CircRNAs in human tissues. The number of circRNAs (structure counts), junction reads (back-splice read counts), circRNA producing genes (gene counts), mean number of circRNA transcripts per circRNA producing genes, and RNAseq library sizes (read counts) are shown. Samples are presented as 4 groups: nucleated tissues, nucleated cell lines, nucleated cell lines digested with RNAse R, and anucleated cell types. The number of back-splice reads is significantly higher in anucleate samples (platelets and RBCs) than all others (P = 2.7 × 104, Wilcoxon rank sum test; figures adjusted for library size). All data were processed using PTESFinder, and all were publicly available with the exception of the data from RBCs (see “Materials and methods” and supplemental Table S1 for details of datasets, and supplemental Table S3 for details of structures).
