Fig. 3. Effects of TEL1 overexpression in the absence of Mec1 or Ddc1. Strains were as follows: wild type (K699), GAL1–TEL1 (DMP3539/10D), mec1Δ sml1Δ (YLL490), GAL1–TEL1 mec1Δ sml1Δ (DMP3562/2A), ddc1Δ (YLL244) and GAL1–TEL1 ddc1Δ (DMP3575/4A). (A–C) Cell cultures growing logarithmically in YEP-raf were synchronized in G₁ with α-factor in the presence of galactose (2 h) and released from the α-factor block at time zero in YEP-raf-gal, or were UV irradiated (40 J/m²) prior to release in YEP-raf-gal. Samples were collected at the times indicated after α-factor release to analyze the DNA content of untreated (top) and UV-treated (bottom) cell cultures by FACS (A), to score the untreated cell cultures for the percentage of binucleate cells by propidium iodide staining (B) and to analyze protein extracts from the untreated (left) and UV-treated (right) cell cultures by western blotting using anti-Rad53 antibodies (C). exp, exponentially growing cells. (D) Serial dilutions of YEP-raf exponentially growing cell cultures were spotted on YEP-raf-gal plates with or without MMS at the concentration indicated. One YEP-raf-gal plate was UV irradiated (UV).