Transient changes in gene expression during stress adaptation are associated with transient changes in the average levels of Gcn5 and histone acetylation relative to histone levels at promoters. The relative average levels (arbitrary units) of H3K18ac (A), H4K16ac (B), H3 (C) and Gcn5 (D) at promoter are plotted. The arbitrary units are independently defined for each of parts A-D. H3K18ac, H4K16ac and Gcn5 levels are shown relative to H3 levels (see Additional file 4 for levels without normalization for H3 levels). Clusters 1–3 are the same as those identified in Figure 4 and the number of genes per cluster is shown in parenthesis. Line colors represent different samples taken during the stress and recovery growth regime.