Gene expression level correlates with chromatin signature complexity. (A) Heat maps of chromatin state enrichment in gene regions (gene length ± 10 kb) for each expression cluster during adipogenic differentiation. Gene ratios (see text) at each differentiation time point are scaled from low-to-high and reflect chromatin state ‘loads’. Time point transitions at which a difference in gene ratios is significant are marked (dot; P < 0.05; t-test with Bonferroni correction). (B) Matrix of statistically significant differences in global state enrichment between expression clusters; P-values are shown in Additional file 2: Table S6A; Wilcoxon test with Bonferroni correction. (C) Chromatin states and RNA-seq profiles at the inactive EOMES locus and at the expressed adipogenic SREBF1 locus; FPKM ranges are shown. (D) Regression analysis of gene expression level as a function of the number of chromatin states, i.e. complexity of chromatin signatures, in gene regions.