Figure 1.ctf7eco1–1 is synthetically lethal in combination with fen1. Yeast cells harboring ctf7eco1–1: ADE were crossed with fen1::KANr mutant cells and the resulting diploids were transformed with a CEN: URA3:CTF7ECO1 plasmid and sporulated. The resulting fen1 and ctf7eco1–1: ADE single mutants and fen1, ctf7eco1–1: ADE double mutants were plated on media with or without FOA (See also Table 1). Two independent isolates are shown for each strain. (A) Growth of fen1, ctf7eco1–1 single mutants and fen1::KAN ctf7eco1–1 CTF7: URA double mutants strains at 23°C on YPD. (B) Growth of fen1::KAN, ctf7eco1–1 single mutants and fen1 ctf7eco1–1: ADE CTF7: URA double mutants on FOA plates at 23°C. (C) Growth of fen1::KAN, ctf7eco1–1 single mutants and fen1 ctf7eco1–1: ADE CTF7: URA double mutants on FOA plates at 30°C (See also Fig. S1). (D) Schematic representation of fen1::KAN, ctf7eco1–1 single mutants and fen1 ctf7eco1–1: ADE CTF7: URA double mutant strains.