FIG. 4.
G1/S and intra-S DNA damage checkpoints in mec1-100 and mec1-101 mutants. The strains used were wild-type (wt) YLL683.8/4A, mec1Δ sml1Δ DMP3048/5B, mec1-100 DMP3343/6C, and mec1-101 DMP3344/4A. (A) Serial dilution of exponentially growing (in YEPD) cell cultures were spotted on YEPD plates with or without MMS (0.005%) or HU. One YEPD plate was UV irradiated (40 J/m2) (UV). The data presented in panels B, C, and D all come from the same experiment. (B to D) α-Factor-synchronized cells were released from α-factor at time zero in YEPD (top) or in YEPD containing 0.02% MMS (middle) or were UV irradiated (40 J/m2) prior to the release in YEPD (bottom). (B) Samples of untreated and UV light- and MMS-treated cell cultures were collected at the indicated times after release from α-factor and analyzed by fluorescence-activated cell sorter. (C) Untreated or UV-irradiated (+UV) cell cultures were scored at the indicated times for the percentage of budded cells. (D) Aliquots were removed from the MMS-treated cultures at timed intervals to score for CFU on YEPD plates at 25°C.