In Saccharomyces cerevisiae , more than 80% of the ∼6200 predicted genes are nonessential, implying that the genome is buffered from the phenotypic consequences of genetic perturbation. To evaluate function, we developed a method for systematic construction of double mutants, termed synthetic genetic array (SGA) analysis, in which a query mutation is crossed to an array of ∼4700 deletion mutants. Inviable double-mutant meiotic progeny identify functional relationships between genes. SGA analysis of genes with roles in cytoskeletal organization ( BNI1 , ARP2 , ARC40 , BIM1 ), DNA synthesis and repair ( SGS1 , RAD27 ), or uncharacterized functions ( BBC1 , NBP2 ) generated a network of 291 interactions among 204 genes. Systematic application of this approach should produce a global map of gene function.
Tong et al. (Fri,) studied this question.