Screening Reluctant Genes on the Double

Abstract

Genome sequencing projects have revealed thousands of genes of unknown functions. For the budding yeast Saccharomyces cerevisiae, large-scale gene deletion analysis has shown that >80% of the ~6200 predicted or known yeast genes are not required for viability. Thus, many genes and pathways of eukaryotic cells may be functionally redundant, or may not show easily recognizable phenotypes if perturbed. To address this problem, Tong et al. developed an automated method for systematic construction of double mutants called synthetic genetic array (SGA) analysis. A yeast strain that carries a mutation in the "query" gene is linked to a selectable marker and crossed to members of a collection of haploid deletion strains in which almost every nonessential gene in the yeast genome is represented. If a double mutant cannot be produced or grows much more slowly than normal, it is an indication that there may be a functional interaction between the two genes. Putative interactions that are identified through this technology can then be readily confirmed by tetrad analysis. Eight query genes involved in cytoskeletal organization, DNA repair, or unknown functions were analyzed, resulting in the construction of a network identifying 291 putative genetic interactions involving 204 genes. A. H. Y. Tong, M. Evangelista, A. B. Parsons, H. Xu, G. D. Bader, N. Pagé, M. Robinson, S. Raghibizadeh, C. W. V. Hogue, H. Bussey, B. Andrews, M. Tyers, C. Boone, Systematic genetic analysis with ordered arrays of yeast deletion mutants. Science 294, 2364-2368 (2001). [Abstract] [Full Text]