Figure 10. Mating pathway activation growth assay of wildtype yeast cells (MH272-1da), as well as of the isogenic strains carrying far1 or ste2 - alleles.

(A) Yeast strains were spotted in serial dilutions (∼1E4, 1E3, 1E2, 1E1 cells in duplicate) onto complete minimal medium, and treated with 1 µg α-factor spotted directly onto the yeast patches. Growth effects were recorded after 2 and 7 days. (B) Comparative growth modulation assay of wildtype yeast cells (MH272-1a) and respective far1 isogenic strain overexpressing human Frizzled receptors (s-Fz1 and s-Fz2), as well as chimeras with the S. cerevisiae Ste2 receptor in a galactose-inducible expression system. The corresponding receptor schemes are shown in Fig. 2 and Fig. 5, respectively. Yeast strains transformed with plasmid constructs as indicated were pre-cultured in glucose-containing minimal medium (repressed), and spotted in serial dilutions (∼1E4, 1E3, 1E2, 1E1 cells) onto glucose- or galactose- (induced) containing minimal medium agar plates selective for the presence of the plasmid. Growth effects were recorded after 4 to 7 days. Controls were the empty expression vector, as well as overexpressed Ste2 and Edg2 receptors.