TABLE 4.

Quantitative mating assays^a

Strain	Mating partner	Mating %	% of mating relative to WT (CAI4)
CAI4	3315α	23.5 ± 1.5	100
Cpp1Δ/Δ mutant	3315α	0.33 ± 0.03	1.4
Cek1Δ/Δ mutant	3315α	0.07 ± 0.02	0.3
GR001	3315α	8.5 ± 0.5	36
GR002	3315α	0.37 ± 0.02	1.6
GR003	3315α	0	0
GR004	3315α	0.09 ± 0.05	0.4

^aTester strains and experimental strains were precultured in SC-glucose liquid medium for 24 h and then mixed in fresh liquid SC-glucose medium at a concentration of 1 × 10⁷ cells/ml for all strains. Mixed cells were incubated at RT for 48 h and then plated onto selection medium to detect auxotrophic mating products. The mating frequency is calculated as described in Materials and Methods. Opaque cells of the mutant GR003 do not mate with opaque cells of the opposite mating type 3315α strain, whereas Cek1Δ/Δ and GR002 mutant strains mate but at reduced frequency. Percentage of reduction in mating was computed by subtracting the percentage of mating of different mutant strains from the percentage of the mating of the wild-type (CAI4) strain divided by the percentage of the mating of the wild-type (CAI4) strain, and the fraction was multiplied by 100.