FIG. 2.

Genome-wide transcription levels for wild-type S. cerevisiae grown on ammonia as the sole nitrogen source plotted versus genome-wide transcription levels for wild-type S. cerevisiae grown on phenylalanine as the sole nitrogen source: average signals in microarrays from glucose-limited chemostat cultures grown with ammonia (n = 4) and phenylalanine (n = 3) as the sole nitrogen sources for all 6,383 yeast open reading frames. The open circles represent genes whose expression was significantly different for the two conditions, while the solid dots represent transcripts whose expression was not significantly altered. The diagonal lines are the boundaries for two- and fivefold differences in signals between conditions. The full data set is available at http://www.phepdc.bt.tudelft.nl.