Fig. 1. Deletion of MDY2 results in a reduction in mating efficiency. (A) Quantitative assay for the mating performance of different mdy2 deletants. Values are means of two independent experiments, and represent the percentage of diploids in the cultures. (B) Shmoo index. Cultures of mdy2 mutant (HZH686) and wild-type (W303-1A) strains were grown to log phase and treated with -factor (final concentration: 5 µM). Aliquots were taken after different times of incubation and the numbers of shmoos in samples of at least 300 cells were counted. (C) Halo assay for -factor production. 0.6% top agar was mixed with 10⁵ indicator cells (MATa sst1). Aliquots (approximately 4x10⁶ cells) of wild-type W303-1B (MAT) and W303-1A (MATa) wild-type and mdy2 mutant cells were spotted directly onto the top agar. The plate was incubated at 30°C for 2 days and photographed. 1. MAT mdy2 mutant cells (HZH683). 2. MAT wild-type cells (W303-1B). 3. MATa wild-type cells (W303-1A).