spt3-401 suppresses spt15-21 for growth and HO expression. (A) Isogenic strains were constructed, differing at the GCN5, SPT15 and SPT3 loci. The gcn5 spt15-21 double mutant had a severe growth defect, but this was suppressed specifically by the spt3-401 allele. The following strains were grown on YEPD medium for 2 days at 30°C: DY151, DY7593, DY5926, DY7597, DY7598, and DY7604. (B) RNA was prepared from the following strains and used for S1 nuclease protection assays: DY151, DY7593, DY7592, DY7594, DY5926, DY7597, DY7596, and DY7598.