Effect of HDAC2 silencing on B-NHEJ in exponentially growing Lig4-/-MEFs. (A) Western blot showing HDAC2 levels 30 h after transfection with siRNA targeting HDAC2 together with the corresponding controls: siNc – negative control siRNA with no target in MEF genome; H2O-Ctrl – water control; Ctrl - non-treated control. GAPDH represents a loading control. Right panel: Cell cycle distribution of the populations employed in the repair experiment shown in the following panels. (B) Yields of DSBs measured by PFGE in cells pre-treated as indicated. The upper panel shows typical gels while the lower panel the average and standard error of FDR calculated from three independent experiments, 2-3 determinations per experiment. (C) Kinetics of rejoining of DSBs in Lig4-/- MEFs exposed to 20 Gy X-rays. The mean and standard errors of Deq calculated from 4-7 determinations in three independent experiments are shown. Other details are as in panel B.