Figure 2.

GC-rich and AT-rich genes differ in levels of acetylation of specific histone tail residues in wild-type cells. Genes were grouped in six groups dependent on the average base composition of the 4 kb region centered on the start site of the gene. For each group average levels of acetylation of different histone tail residues were determined using a dataset obtained by Kurdistani and co-workers [36]. (a-d) GC-rich genes display higher levels of H4K8, H4K12, H3K9 and H3K18 acetylation compared to AT-rich genes. (e) Comparison of the average levels of 11 histone modifications for GC-rich genes (GC > 40.4%) and AT-rich genes (GC < 36.6%). H3 and H4 acetylation is higher for GC-rich genes, whereas H2A and H2B acetylation is not different for the two types of isochore domains.