FIGURE 2: Prions improve chronological lifespan.

(A) Chronological lifespan analysis, as determined by propidium iodide uptake to assess yeast cell death, is shown for [PIN⁺][PSI⁺], [PIN⁺][psi^–] and cured [pin^–][psi^–] versions of wild-type and atg1 mutant strains. Cells were grown in SCD media for 3 days to reach stationary phase and then aliquots taken every 2-3 days for flow cytometry analysis based on propidium iodide uptake by non-viable cells as assayed through flow cytometry. Data shown are the means of at least three independent biological repeat experiments expressed as the percentage of viable cells out of 10000 cells analyzed. Error bars denote standard deviation.

(B) Viability measurements are shown for [PIN⁺][PSI⁺] and [PIN⁺][psi^–] strains grown under the same conditions as for (A) above. Viability is expressed as a percentage of day zero.