Fig. 4.

Analysis of alternative (back-) splicing in circular RNAs. a Schematic diagrams of two types of alternative back-splicing (5′ and 3′), and number and percent of alternative back-splicing events by sample and diagnosis. Red polylines show canonical splicing and red arc lines indicate back-splicing (circularization). b–e Schematic diagram of four basic types of alternative splicing in circRNAs and their quantifications from schizophrenia and control groups. Alternative splicing events were measured by and PSU for alternative 5′ splice site selection (b), alternative 3′ splice site selection (c), PSI for cassette exon inclusion/exclusion (d), and PIR for intron retention (e). f Comparison of total number of mapped reads from schizophrenia and control cohorts