Transcriptional changes in regulatory networks. The information regarding the regulatory networks is from RegulonDB. The genes under the control of the same transcription factor (TF) or sigma factor were assigned to the same group. The nodes and arcs represent genes and regulation, respectively. The large nodes denote sigma factors or regulators that control more than 15 genes. The genes with conserved expression are shown in gray, and those with notable transcriptional changes are shown in color. The increased and decreased expression levels resulting from genome reduction (A) or heat shock (B) are quantitatively marked as gradations, as indicated in the scale bar. Vivid orange indicate highly significant increases in expression, and dark purple represent highly significant decreases in expression.