Figure 3.

FOL1 is an essential gene.(A) Schematic representation of a FOL1 deletion using the kanMX PCR-generated gene deletion cassette. (B) Tetrad analysis of the heterozygous diploid fol1 deletion strain CEN.HE4 on YPD supplemented with folinic acid as indicated. The genotype of the spores is shown. Plates were incubated at 30°C for 72 h. Spores carrying the fol1Δ deletion germinated on media without folinic acid and went through 4–6 cell divisions before stopping to divide. This nongrowth phenotype could be rescued by addition of folinic acid.