FIGURE 1: Increased frequency of [PSI⁺] prion formation during chronological lifespan.

[PIN⁺][psi^–] versions of the wild-type and atg1 mutant stains were grown to stationary phase in SCD media and the frequency of [PSI⁺] formation measured over time. [PSI⁺] formation was quantified using the ade1-14 mutant allele by growth on media lacking adenine and differentiated from nuclear mutations by their irreversible elimination in GdnHCl. Data shown are the means of three independent biological repeat experiments expressed as the number of colonies per 10⁵ viable cells. Error bars denote standard deviation. Significance is shown comparing the wild-type and atg1 mutant strains over time (above bars) as well as between the wild-type and atg1 mutant at each time-point (between bars). Statistical analysis was performed by one-way ANOVA: *p < 0.05, **p < 0.01.