Figure 3.—

Sae2 influences DNA repair events that require the Mre11 nuclease activity. Integrated sae2 alleles were examined for their phenotypes. (A) MMS and CPT sensitivity of sae2 single mutants (1/5 serial dilution). (B) MMS and CPT sensitivity of sae2 mutants in the absence of MEC1 (1/5 serial dilution). (C) The ability to remove Spo11-DNA intermediates. Accumulation of unprocessed DSBs in sae2 mutant diploids was determined by Southern blot. Cells were collected at 4.5 and 9 hr after meiosis induction. EcoRI-digested genomic DNA prepared from these cells was examined for accumulation of unprocessed DSB at the THR4 locus by Southern blot. The unprocessed DSBs were detected as a discrete 5.7-kb fragment band. (D) Sporulation efficiency. Cells were collected at 48 hr after meiosis induction and stained with DAPI. The percentage of tetrads was plotted.