FIG. 1.

α-Pheromone induces a dramatic increase (>100-fold) in adhesion in white cells of all tested a/a strains of C. albicans. The methods of Daniels et al. (5) were employed (see the supplemental material). In brief, white cells were incubated for 16 h at 25°C in supplemented Lee's medium (1) in the wells of cluster well plates in the absence (−) or presence (+) of 10⁻⁶ M α-pheromone (13-mer). Well bottoms were then gently rinsed, photographed, and then scraped and the suspended cells counted. (A) Histogram of the average number of cells adhering to the well bottom for each of 10 a/a strains. Those strains with a/a in parenthesis were obtained by treating the noted wild-type a/α strain with sorbose (6), screening for opaque sectors (MTL-homozygous offspring), and genotyping for a/a strains by PCR (9, 15). Three a/a derivatives of the laboratory strain SC5314 were also tested. The origins and genotypes of the tested a/a strains are provided in Table S1 in the supplemental material. The mean of results from three well bottoms plus the standard deviation (error bar) are presented for each strain. α-ph, α-pheromone. (B) The well bottoms for strain L26 in the absence (−) or presence (+) of α-pheromone were representative of all a/a strains tested.