Figure 4.

Examples of gene subgrouping within broad functional classes. Expression profiles for several sets of genes after combining experiments under different conditions. The experiments are color-coded (upper bar) as follows: yellow (cell cycle), orange (sporulation), red (stress) and purple (diauxic shift). (a) Subgroups obtained from the 'L - -' class ('DNA replication, recombination and repair'). (b) Subgroups obtained from the 'O - -' class ('post-translational modification, protein turnover and chaperones'). (c) Subgroups obtained from the 'GEPR - -' class, which contains permeases of the major facilitator superfamily. GEPR comprises several functional groups reflecting that their actual function is not clear (R) although they may be involved in the transport of sugars (G), aminoacids (E) and inorganic ions (P). The vertical axis represents the differential expression of genes as the log ratio of the mRNA abundance in experimental versus control samples. At zero values, the mRNA levels are identical. The list of genes included in every subgroup can be found in the additional data files.