Figure 6.—

Phenotypes of double mutants combining ade3 mutations with mutations in folate metabolism. (A) Growth of the four spores of a tetratype obtained by mating Y06591 (ade3) and Y16179 (fau1) strains. A serial dilution of the spores was dropped onto YPD medium, and growth of cells was observed after 2 days at 30°. (B) Growth of the ade3 fau1 double mutant in the presence or the absence of methionine. Strains Y16591 (ade3), Y2030 (ade3 met6), Y2031 (ade3 fau1), and Y2032 (ade3 fau1) were streaked onto SD medium with (+met) or without (−met) methionine, and growth of the strains was observed after 3 days at 25° or 30°, as indicated. (C) The Y06591 (ade3) strain was mated with either Y13403 (shm1) or Y12669 (shm2) strains, and after sporulation of the resulting diploids, 12 tetrads (shown as vertical alignments of four spores) were dissected onto YPD medium supplemented with adenine (0.3 mm). Growth of spores was observed after 3 days at 30°.