Fig. 3. mfr1⁺ is required for sporulation. A wild-type diploid (Sp785) and a mfr1/mfr1 mutant (Sp963) were sporulated on agar plates containing malt extract (sporulation medium). (A) Photographs of cells after 48 hours using interference microscopy (top) and DAPI staining (bottom). In the mfr1/mfr1 mutant most cells contained four nuclei, as in the wild type. These nuclei were difficult to photograph because they were on different focal planes. (B) Percentage of asci after 48 hours with 4, 3, 2, 1 and 0 spores.