Figure 4

Transcriptional activity of major functions. Histograms representing Mean read numbers per COG class for STM 2683 (A) and STM 4661 (B) in the three treatments (Zinc, Control and Cadmium). The median read numbers per class and per treatment (last bars on the histograms) were used to draw the dotted line above which classes can be considered as transcriptionally over-active and those below as under-active.