Figure 2. [RNQ⁺] prions from wild yeast induce [PSI⁺] at levels similar to a previously-characterized high [RNQ⁺] variant.

A. For each wild strain donor, Sup35 was O.E. in two different 74-D694 [RNQ⁺] cytoductants to induce [PSI⁺]. Colonies were scored as [PSI⁺] as detailed in Materials and Methods. Experiments were repeated at least three times and at least 300 colonies were scored for each clone, per experiment. Four wild [rnq⁻] control cytoductant strains, which lacked Rnq1 aggregates by SDD-AGE (Supplemental Figure 2), never induced [PSI⁺], indicating that the cytoduction protocol did not readily generate spontaneous [RNQ⁺]. B. [PSI⁺] colonies were isolated and re-grown on YPD, SD-Ade, and YPD + 3mM GdnHCl solid media, for verification and scoring of [PSI⁺] variants. Between 200 and 600 [PSI⁺] colonies from 3 separate experiments were isolated for each wild strain donor and scored for the strength of the [PSI⁺] variant. C. Example spotting plates of yeast with one representative strain from each of the three groups. Controls are the first three spots of the top row: strong [PSI⁺] (S), weak [PSI⁺] (W) and [psi⁻] (-).