Figure 2. The yeast mating pathway is robust to domain rearrangement-mediated gene replacements.

(A) Mating pathway activation was determined by flow cytometry, measuring the fluorescence intensity of a GFP reporter controlled by a mating-responsive FUS1 promoter, 2 hours after addition of 1 µM α-factor. (B) As expected, individual deletions of the pathway components Ste50, Ste20, Ste7, Ste4, Ste11, Ste5, or Ste18 eliminate pathway activation [51],[52]. (C) Mating pathway activation for the library of domain rearrangement variants expressed in individual deletion strains. Rearrangement events that recreate WT genes are marked as “WT.” Repeated attempts to transform variant Ste50[N]-Ste18[C] failed, suggesting that it may result in cell toxicity. For a statistical analysis of the results see Figure S4. Data shown in Data S1.