FIG. 5.

DSB formation and repair in glc7 mutant cells. Exponentially growing wild-type (wt), glc7-129, glc7-132, and glc7-T152K SCraf-Ura cell cultures (raf), all carrying the MATa allele and expressing the HO gene from the GAL1 promoter, were transferred to YPgal to induce HO expression. After 1 h, cells were transferred to medium containing glucose to allow cells to repair the HO-induced break (time zero). StyI-BamHI-digested genomic DNA prepared from cell samples collected at the indicated time points after galactose removal was subjected to Southern blot analysis with a MAT probe that detects 0.9-kb fragments (MATa) in the absence of HO-cut, while HO-induced DSB formation results in generation of HO-cut (0.7-kb fragment), which can be eventually repaired by HR with donor sequence HMR or HML, generating MATa (0.9-kb) and MATα (1.8-kb) repair products, respectively.