FIG 3.
pH regulates the induction of MFA1 expression in response to α-pheromone (produced by opaque α cells). A GFP-encoding sequence was integrated into the MFA locus and used as a reporter of the MFA1 promoter. Opaque α cells of GH1349, which served as an α-pheromone producer, were mixed with opaque a cells of the PMFa1-GFP reporter strain. Single-strain cultures (GH1349 and the reporter strain) served as controls. Cells were incubated in liquid Lee's glucose medium with shaking at 25°C for 24 h. DIC, differential interference contrast.