Fig. 2

Identifying FP BSJ reads from tandem RNAs. Mapping location of the read mate of a BSJ-supporting read may help to detect FP BSJ reads. The vertical blue dash-line represents the location of BSJ in the true circRNA (top) and the tandem RNA (bottom). The BSJ region is surrounding the BSJ of the circRNA, defined by the area of (\(L-a\)) bases from the BSJ, where L and a are read length and anchor length respectively. All read pairs are originally from the tandem RNA. Upper dashed-box: BSJ read-pairs with one read mapped outside the circRNA putative region identified as false positives (FPs). Bottom dashed-box: read pairs from short fragments are completely located in the putative circRNA region, thus in this case the reads are not identified as FPs