Fig. 1

DNA polymerases in Cas9-induced large resections. Significant increases of resistance to 6-thioguanine (A, B) and decreases of normal splicing (C) by Cas9-induced large resections of HPRT1 upon knockdown of PolQ or PolL. Significant increases of sensitivity (D, E) and decreases of normal splicing (F) by Cas9-induced large resections of DCK upon knockdown of PolQ or PolL (see Additional file 5: Table S3, n = 2 replicates, mean ± SEM). Spliced HPRT1 (C) and DCK (F) cDNAs are TA cloned and confirmed by Sanger sequencing in both orientations. Confirmation of large resections by DNA sequencing during DNA-fragment deletion (G) and inversion (H) as well as at the upstream cleavage junction (I) programmed by Cas9 with dual sgRNAs. Schematic (J) of LAM-HTGTS with biotinylated and nested primers and simultaneous assessment of DNA-fragment deletion and inversion (K) by next-generation sequencing (NGS). Significant decreases of repaired DNA, measured as ratio of reads with junctions to the total number of reads, upon knockdown of PolQ or PolL (L) (see Additional file 5: Table S3, n = 2 replicates, mean ± SEM). Significant increases of Cas9-induced large resections during DNA-fragment deletion (M, P) and inversion (N, Q) as well as at the upstream cleavage junction (O, R) assayed by NGS upon knockdown of PolQ (P–R). Percentages of rare resection products were quantified as ratio of large resection reads to the total number of reads