Senescence progression assays
Serial liquid culture senescence progression assays were carried out as described previously (Le et al. 1999; Rizki and Lundblad 2001). To summarize, spore colonies from freshly dissected tetrads were inoculated in their entirety into YPD media and grown at 28° for 46 hr. Cell counts were determined via hemocytometer. Samples were diluted back into fresh media to a concentration of 1 × 105 cells/mL and grown for 22 hr at which time cells were counted. The cultures were again diluted back into fresh media to a concentration of 1 × 105 cells/mL. Cell counts and dilution into fresh media were repeated every 22 hr. Several isolates of each genotype were examined.