FIG. 2.

Sensitivity of the rad12::ura4⁺ mutant to DNA damage and transient inhibition of replication. Shown are UV light (a), γ radiation (b), and HU (c) survival curves of the wild-type (Sp30) (•), rad12-502 (Sp272) (▪), and rad12::ura4⁺ (Sp358) (▴) strains. (a and b) Strains were grown to mid-log phase, plated at appropriate dilutions, and treated with the indicated doses of radiation. Colonies were allowed to grow 4 days at 32°C, at which time the numbers of colonies were determined. Colony numbers were normalized to those of the nonirradiated samples. (c) Strains were grown to mid-log phase; then HU was added to 12 mM. Samples were removed from the HU at the indicated times and transferred to plates for viability testing. Colonies were allowed to grow 4 days at 32°C, at which time the numbers of colonies were determined. Colony numbers were normalized to those of the samples harvested at the time of addition of HU (time = 0). In all cases, error bars represent the standard deviations of the data. Where error bars are not visible, they are smaller than the symbols representing the data points.