Figure 3

Effect of DNA damaging agents and hydroxy urea on csn deletion strains (A) 10² cells of csn mutant strains were spotted onto YPD plates followed by irradiation with the indicated doses of UV light (0 – 120 J/m²). The UV-sensitive Δrad14 strain was used as a positive control for the effect of UV. (B) 10² cells of csn deletion strains were spotted onto a YPD gradient plate containing 0% to 0.03% methyl-methane sulfonate (MMS) as indicated. Plates were incubated for 3 days at 30°C. The MMS-sensitive strain Δrad14 is shown as a positive control for the effect of MMS. (C) 10² cells of csn deletion strains were spotted onto a YPD gradient plate containing 0 to 200 mM hydroxyurea (HU) as indicated and cell growth was determined after incubation for 3 days at 30°C. The HU-sensitive strain Δpol32 is shown as a positive control for the effect of HU. (D) The indicated wild-type and csn deletion strains were grown in YPD to an optical density of ~1, followed by fixation in 70% ethanol. Cells fixed for 24 h at -20°C were washed once in 50 mM sodium citrate and resuspended in the same buffer containing 100 ug/ml preboiled RNAse A, followed by incubation at 37°C for 2 h. Propidium iodide was added to a final concentration of 4 ug/ml, and the cellular DNA content was determined by flow cytometry.