Gene clusters upregulated during nitrogen deprivation. The fold change in RPKM from 0 to 6, 12, and 21 hours after removal of combined nitrogen is represented in a heat map across the chromosome. Genes are shown in order from all0001 at the top to all5371 at the bottom. Clusters of genes that are upregulated and discussed in the text are marked with an asterisk and locus identifiers. The heat map was produced with The Broad Institute's GenePattern software and the dataset (additional file 8: RPKM GenePattern.gct) can be analyzed with the free GenePattern software .