(A) Outline of the SpSGA method. Cells of opposite mating type (h+, h−) are mated on minimal SPA media and allowed to sporulate for 3 days at 26 °C. Then, to enrich for spores, mating plates are transferred to 42° for 3 days—a treatment that kills unmated haploid cells. Following spore enrichment, cells are transferred to rich medium to allow for germination, then transferred again to double-drug medium to select for recombinant double-mutant progeny. S. pombe haploids do not mate on rich medium; therefore, selection for a specific haploid mating type is not required. (B) A portion of the final 1536-formatted miniarray screening plate (YES+Nat+G418) showing a comparison of two queries, a representative control, ura4::kanMX4 (ura4Δ), and a representative query gene, swi3::kanMX4 (swi3Δ). Novel genetic interactions are identified between swi3Δ and mrc1Δ, rad17Δ, ddb1Δ, and fbh1Δ and confirmed by tetrad dissection. Arrows indicate the position of the double deletion mutant, which in one of every four cases is inviable or slow growing.