FIGURE 6.

Synthetic genetic effect of nrd1 alleles with the nab3-11 allele. A strain with a nab3-11 chromosomal allele was mated to a strain with either the nrd1Δ6–150 (left) or the nrd1Δ151–214 (right) chromosomal allele. The resulting diploids were transformed with a URA3-marked plasmid containing NRD1, sporulated, and plated onto FOA-containing medium at 22 °C. The growth phenotype for a set of tetrad sibs is shown for each with the relevant NAB3 and NRD1 genotypes indicated. Cells with the nab3-11 and nrd1Δ6–150 alleles were very slow growing (Spore3, left), and cells with both the nab3-11 and nrd1Δ151–214 mutations were not viable (Spore3, right).