Figure 5.
Effect of Dis2 on the G2 checkpoint requires Rad3-dependent phosphorylation of Chk1. (A) Strains were streaked onto minimal medium agar containing phloxin B and lacking thiamine, and were grown at 30°C for 3 days to determine cell viability. nmt1::chk1 refers to strains where a single copy of nmt1::chk1 was integrated into the genome, and integrated pRep5 acted as a control for these strains. Vector refers to cells transformed with pRep1, which acted as a control for cells overexpressing Dis2 from an nmt1::dis2 plasmid. (B) Strains shown in (A) were grown in the absence of thiamine for 16 h at 30°C, DAPI-stained and measured for average cell length±standard deviation (μm, n=25). (C) Synchronous G2-phase chk1Δdis2Δ cells, obtained by centrifugal elutriation, were treated with 150 J/m2 UV-C radiation (○) or left untreated (•), and the per cent of cells passing mitosis or with aberrant mitoses was followed over time (compare with Figure 2D).