Figure 2.

IR-sensitivity of H2AX^−/− ES cells expressing H2AX mutants. (A) Survival rate of H2AX^−/− ES cells expressing individual H2AX mutants after exposure to IR. Each survival rate, normalized to transfection efficiency and plating efficiency, represents mean of triplicate samples. Error bars indicate standard error of the mean (s.e.m.). (B) Steady-state level of HA-tagged H2AX mutants expressed in H2AX^−/− ES cells. Treatment with 10 Gy of IR is indicated. γ-H2AX, HA-H2AX and HA-uH2AX as shown are detected by anti-γ-H2AX and anti-HA antibodies respectively.