Figure 5.—

Haploid cells under negative selection can mate to form heterozygous MRA escape colonies. The indicated SGA query strains harboring a Tet-RNR1∷ClonNat allele were mated with a ptc1Δ0∷KanMX deletion array strain of the (A) opposite or (B) same original mating type by cospotting overnight YPD cultures onto SGA haploid selective media lacking canavanine. A depicts 4-μl droplets of cultures that were cospotted. B (since these events were rare) depicts an area of a petri dish over which 100 μl of culture were coplated.