Fig. 8.

STEEx are counter selected upon exit from quiescence. a Wild type and ter1∆ single cells were maintained in quiescence for 1, 4, or 8 days, micromanipulated and plated onto YES plate allowing them to exit quiescence (refer to Fig. 1 for senescence and quiescence). The percentage of cells that were not able to form a colony was plotted. Microscopic observation was performed to determine how cells died when they re-enter into cell cycle. We distinguished single-round cell, enlarge cell, and micro-colony (1–20 cells). Round cell died in G0 while enlarged or micro-colony attempted to exit G0. b Left panel, at several time points of the senescence kinetics (S1, S3, and S5) a population of 8-days quiescent cells were allowed to exit G0 by changing medium to YES. Cells were grown for 1, 2, or 3 days in YES medium and collected. Genomic DNAs were prepared from the collected cultures, digested with EcoRI and analyzed by southern blot with a Telo/STE1 and control probes. STEEx are indicated by asterisks. Right panel, pulsed field gel electrophoresis (PFGE) analysis was performed with the indicated samples (S1D8, 1 day in senescence, 8 days in G0, and 1 day after exit; S5D8, 5 days in senescence, 8 days in G0, and 3 days of growth after exit). Gel was stained with ethidium bromide