Figure 5

Characterization of the chromatin environments of the matched gene groups with respect to silent histone marks. (A) The levels of histone marks associated with silent chromatin were analyzed at specific intervals around the promoters of the three gene groups (group 1: "long-range repression", group 2: "limited repression" and group 3: "absence of repression"). The calculations were based on ROC curve analysis as described in Figure 4. Non-central chi-square statistical analysis compared differences between group 1 and group 2, and group 1 and group 3. The p-Value Legend is * p < 0.05; ** p < 0.01. The histone modifications in the analysis included H3K9me2, H3K9me3, H3K27me3 and H4K20me3, mainly associated with silent chromatin. (B) Relevant histograms representing relative H3K9me3 and H4K20me3 values over 1 kb and 10 kb, which reached statistically relevant differences when the three groups were compared.