Abstract

Temporal control of gene expression is a widespread feature of cell cycles, with clear transcriptional programs in bacteria, yeast, and metazoans. In budding yeast, approximately 1,000 genes are transcribed during a specific interval of the cell cycle. Although a number of factors that contribute to this periodic pattern of gene expression have been studied in Saccharomyces cerevisiae, pathways of cell cycle-regulated transcription remain largely undefined. To identify regulators of genes exhibiting cell cycle periodicity, we have developed a functional genomics approach termed reporter-based synthetic genetic array (R-SGA) analysis. Based on synthetic genetic array (SGA) analysis, R-SGA allows rapid and easily automated incorporation of a cell cycle reporter gene into the array of viable haploid yeast gene-deletion mutants. Scoring of reporter activity in mutant strains compared to wild type identifies candidate regulators of the cell cycle gene of interest. In contrast to microarrays, which generally provide information about the expression of all genes under a particular condition (for example, a single gene deletion), R-SGA analysis facilitates the study of the expression of a single gene in all deletion mutants. Our system can be adapted to examine the expression of any gene not only in the context of haploid deletion mutants but also using other array-based strain collections available to the yeast community.