Heatmap of T. thermophila P450 gene expression patterns. The levels of expression are illustrated by different grades of color scale determined on the basis of the microarray data, as indicated from the top bar (From left to right): Dark color: low expression; light color: high expression. P450 gene names are shown on the y-axis and the three physiological stages examined on the x-axis. The "monster gene" represents the false prediction of merging the three P450 genes (CYP5013A1, CYP5013C1 and CYP5013B1) into one gene by TIGR, resulting in their being combined on the microarray. Vegetative growth: L-1, low cell density (100,000 cell/ml); L-m, medium density (350,000 cell/ml); L-h, high cell density (1,000,000 cell/ml); Starvation: S0, 0 h; S3, 3 h; S6, 6 h; S9, 9 h; S12, 12 h; S15, 15 h; S24 24 h; Conjugation: C0, 0 h; C2, 2 h;C4, 4 h; C6, 6 h; C8, 8 h; C10, 10 h; C12, 12 h;C14, 14 h; C16, 16 h; C18, 18 h.