Figure 2.

Characterization of the xrs2 mutants. (A) SYT358a (MATa xrs2Δ::URA3 ade2 ade3 trp1Δ leu2-3,112 ura3Δ lys2-801 can1) containing integrations of the indicated xrs2 alleles were examined for telomere length. (B) Complementation of the synthetic senescence phenotype exhibited in xrs2 mec1 sml1 hdf1 mutants. The indicated xrs2 alleles present on CEN plasmids (ARSH4 CEN6 LEU2 CYH2) were introduced into SYT301 harboring the plasmid pYT1501. The cells that are viable after loss of pYT1501 can grow on SC (+5-FOA -Leu) plates. (C) Sensitivity to MMS and HU in the xrs2 mutants with indicated alleles. Fivefold serial dilutions of the indicated xrs2 mutants were spotted onto YPAD plates containing 0.01% MMS or 25 mM HU. The xrs2 mutants examined in this assay are the SYT358a derivatives in which the truncated xrs2 genes were integrated into the genome.