Fig. 1
From: DNA double-strand breaks in telophase lead to coalescence between segregated sister chromatid loci
Phleomycin triggers the DNA damage checkpoint to delay telophase-G1 transition. a Rad53 gets hyperphosphorylated in telophase after phleomycin treatment. Strain FM2329 was arrested at the indicated cell cycle stages. Phleomycin (10 µg mL−1) was then added and cells were harvested after 1 h for western blot analysis. MMS (0.01%), added to an asynchronous culture, was used as Rad53 hyperphosphorylation control. The leftmost lane in the Ponceau staining corresponds to the protein weight markers. b Cytokinesis is delayed after phleomycin treatment in telophase. Strain FM593 was arrested in telophase, the culture split into two and one subculture treated with phleomycin. After 1 h, phleomycin was washed away and both subcultures were released from the telophase block, taking samples every hour for plasma membrane abscission analysis using Hoechst staining. The G1-blocking pheromone alpha-factor (αF) was added at the time of the telophase release to simplify cell outcomes. On the top, representative micrographs of telophase cells with different degrees of cytokinesis completion. Scale bar corresponds to 5 µm; BF, bright field. At the bottom, charts showing the march of cytokinesis during the telophase release (one representative experiment ± CI95). c Sic1 synthesis (G1 marker) is delayed after DSBs in telophase. FM2323 was treated as described in panel (b), taking samples for western blot analysis. d Cell separation and entry in a new S phase is blocked after DSBs in telophase. FM593 was treated as described in panel (b). In this case, though, αF addition was omitted. Samples were taken for FACS analysis. DNA content (1C, 2C or 4C) is indicated under each FACS profile. Filled arrowheads point to the 1C peak; hollow arrowhead points to the 4C peak. e Sic1 synthesis is not delayed in strains impaired for the DNA damage checkpoint. FM2477 was treated and samples processed as described in panel (c). f Cell separation and entry in a new S phase is not blocked after DSBs in telophase in strains impaired for the DNA damage checkpoint. FM916 was treated and samples processed as described in panel (d). Source data are provided as a Source Data file
