Figure 1.ctf7^eco1–1 is synthetically lethal in combination with fen1. Yeast cells harboring ctf7^{eco1–1: ADE} were crossed with fen1::KAN^r mutant cells and the resulting diploids were transformed with a CEN: URA3:CTF7^ECO1 plasmid and sporulated. The resulting fen1 and ctf7^{eco1–1: ADE} single mutants and fen1, ctf7^{eco1–1: 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, ctf7^eco1–1 single mutants and fen1::KAN ctf7^eco1–1 CTF7: URA double mutants strains at 23°C on YPD. (B) Growth of fen1::KAN, ctf7^eco1–1 single mutants and fen1 ctf7^{eco1–1: ADE} CTF7: URA double mutants on FOA plates at 23°C. (C) Growth of fen1::KAN, ctf7^eco1–1 single mutants and fen1 ctf7^{eco1–1: ADE} CTF7: URA double mutants on FOA plates at 30°C (See also Fig. S1). (D) Schematic representation of fen1::KAN, ctf7^eco1–1 single mutants and fen1 ctf7^{eco1–1: ADE} CTF7: URA double mutant strains.