Figure 2.—

Small a-regulated MRA escape colonies retain an α-mating type, while large MRA escape colonies are either sterile or a-mating type. Overnight grown cultures of strains (A) Y15110-3-4.1b (can1Δ0∷P_can1-P_MFA1-his3/HMRa) and (B) Y15572-3-30.3b (can1Δ0∷P_GAL1-T_ADH1-P_MFA1-his5⁺/hmraΔ0∷URA3ca) were first treated as in Figure 1. After 3.5 days, MRA escape colonies were replica plated to SC−HIS media, and coreplica plated with mating-type tester strains on YPD. After 1 day, strains tested for mating-type complementation were replica plated to media lacking all amino acids, and plates were imaged 1 day later.