Fig. 7. elg1Δ mutants are defective in recovery from MMS-induced replication fork stalling. (A) S phase progression in the presence of MMS. Wild-type or elg1Δ cells were arrested in G₁ (t = 0) and released synchronously into medium containing 0.035% (v/v) MMS. Samples were removed at the indicated times and analyzed by flow cytometry. The shaded histograms represent the cell cycle distribution of the asynchronous cultures before the G₁ arrest. Overlaid histograms represent the cell cycle distribution at the indicated times after release from the G₁ arrest. (B) Checkpoint activation of Rad53 during recovery from MMS damage. Cells were arrested in G₁, released into MMS for 1 h, and then transferred to medium lacking MMS (t = 0). At the indicated times, samples were withdrawn and Rad53 activation was analyzed by immunoblotting.