fpr1Δ and hom6Δ mutations are synthetically lethal. (A) Tetrad analysis of an FPR1/fpr1Δ::nat HOM6/hom6Δ::kan diploid. Spores from strain MAYX118 were dissected on solid YPD medium, and each tetrad was arrayed in a column. Plates were incubated at 30°C for 3 days, photographed, and replica plated to YPD plates containing 200 μg of G418/ml, 70 μg of nourseothricin (Nat)/ml, or both. Replica plates were incubated for 2 days and photographed. (B) Tetrad analysis of strain MAYX118 transformed with URA3 plasmids expressing FPR1 (pYJH23) or HOM6 (pMA-HOM6) or with a URA3 control vector (pSEY8). Transformants were grown in medium selective for the plasmids (SC-uracil) and transferred to sporulation medium, and spores were dissected and analyzed as for panel A. SC-uracil and 5-fluoro-orotic acid plates were included in this assay.