FIGURE 4.

Increased abundance of Age1, Age1ΔN, or Sfh2 bypasses the requirement for the essential Age2 + Gcs1 ArfGAP pair. Diploid cells heterozygous for age2Δ and gcs1Δ deletion mutations and harboring high-copy plasmids carrying vector (A), AGE1 (B), AGE1ΔN (C), or SFH2 (D) were sporulated, and the resulting haploid segregants were incubated on solid selective medium at 30 °C for 5 days. Arrows indicate age2Δ gcs1Δ double-mutant segregants that are either nonviable (A) or kept alive by the plasmid-borne gene (B–D).