fluorescence signal per focus (D) at times 1 or 2 (peak) and 7 hours from the time course shown in (B). Representative images of wild-type and mutant cells with MMS-induced RPA foci (bright field and fluorescence signal) are shown (D; left panels). Data information: The mean and SEM of 3 independent experiments are shown. Asterisks indicate statistically significant differences according to an unpaired two-tailed Student's t-test. One, two and three asterisks represent p-values <0.05, <0.01 and <0.001, respectively. 