10

010

Days after X-rays

% A

popt

otic

nuc

lei 20

A B

2 3 4 55

Rel

ativ

e ce

ll N

o.

50

010

100

2 3 4 55

Days after X-rays

7 7

**

**** **

**

****

****

**

**

Figure S2

Apoptotic cell death caused by 5 Gy of X-rays. A, Time-dependent increase in apoptotic nuclei, which were detected by homogeneous nuclear staining by anti-phosphorylated histone H2AX antibody. B, Time-dependent change in the cell number, which was determined as described in Materials and Methods. The data represent the mean ± SEM. Significance was evaluated between the control and irradiated cells. **p < 0.01.