Effect of twenty-one different nitrogen sources on global gene expression in the yeast Saccharomyces cerevisiae

We have applied whole-genome microarray hybridization to compare the transcriptome of wild-type yeast strain Σ1278b during growth on a minimal medium containing 21 different single nitrogen sources including urea used as a reference condition. Keywords: growth conditions comparison The 21 compounds were selected from a list of 27 nitrogen sources for their ability to support reproducible growth with a generation time (g) of less than 5 hours. The reference nitrogen source to which the twenty other media were compared in terms of genome expression was urea, chosen because urea catabolism and its regulation are well known, because the generation time of strain Σ1278b on urea is near the middle of the studied g range, and because the major regulations like nitrogen catabolite repression (NCR) and SPS-mediated control are not operational on this medium.