Figure 7.

Ambiguous cells have selective advantage under stress. Spores of S. cerevisiae control cells and cells expressing the G₃₃ tRNA_CAG^Ser were grown for 7 days in agar plates of rich medium (YEPD), synthetic medium (SD) and minimal medium (MM) containing 100 μM CdCl₂ or 1.5 mM H₂O₂. Spores from ambiguous cells grew much slower than non-ambiguous spores in rich medium, but recovered competitive capacity when growing under stress conditions, as shown by a similar colony size of control and ambiguous cells.