FIG. 1.

p53 is required for cell cycle arrest following nocodazole treatment. (A) FACS profiles of wild-type and p53^−/− MEFs untreated or treated with nocodazole for 24 h. DNA content is represented on the x axis; number of cells counted is represented on the y axis. Data shown are representative of multiple experiments performed on two different wild-type and p53^−/− clones. (B) Immunofluorescent staining of wild-type and p53^−/− MEFs. MEFs were treated with nocodazole for 24 h, pulsed with BrdU in the presence of nocodazole for an additional 4 h, and fixed. Immunofluorescence was performed to detect BrdU incorporation (α-BrdU) and nuclear staining (DAPI). Immunofluorescence was performed on two different wild-type and p53^−/− clones.