Fig. 5

Fill-in of staggered Cas9 DSB ends by Polλ. Significant decreases of templated 1-3bp insertions at Cas9 cleavage junctions programmed with dual sgRNAs at the MAZ (A, B), MeCP2 (C, D), PARP1 (E, F), PRDM5 (G, H), and YY1 (I, J) loci upon PolL knockdown in HEC-1-B cells. As positive controls, the trends of templated insertions upon Ku70/80-knockdown are similar as those of Polλ-knockdown (see Additional file 5: Table S3, n = 2 replicates, mean ± SEM). K Schematic of the role of Polλ and Polθ in repairing Cas9-induced DSB ends