FIG. 4.

Recapitulation of synthetic interaction using Gal-Dre2. Gal-Dre2 (98-67) was crossed with the Δmrs3 Δmrs4 strain (87-13), sporulated, and dissected on glucose or galactose plates. (A) Shown are tetrad spore clones from dissection on a glucose plate. The boxed tetrad is a tetratype with indicated genotypes. The spore clone in row d presumed to represent Gal-Dre2 Δmrs3 Δmrs4 was microscopically visible and was arrested at fewer than 20 cells. (B and C) Tetrad clones of various genotypes were rescued from a galactose plate and diluted in water, and serial dilutions were spotted on a galactose plate (B) or glucose plate (C). Note the slight growth defect of induced Gal-Dre2 Δmrs3 Δmrs4 on the galactose plate, indicating a synthetic dosage effect. On the glucose plate, the triple mutant (repressed Gal-Dre2 Δmrs3 Δmrs4) was more severely compromised than the individual mutants, the Gal-Dre2 or the Δmrs3 Δmrs4 strain.