Transcription-coupled shifts of histone modification peaks enriched in the 5' end of CpG promoter genes. (a-h) Average profiles of expression-matched CpG and non-CpG genes (a, c, e, g) and heat maps of all genes (b, d, f, h) for H3K9me1 (a, b), H3K4me2 (c, d), H3K4me1 (e,f) and H3K27me1 (g, h). In the heatmaps, each row represents one gene and each column a single nucleotide position. (i-l) Plots of the correlation between expression level and peak modification position for H3K9me1 (i), H3K4me2 (j), H3K4me1 (k), H3K27me1 (l) at CpG and non-CpG promoter genes. The x-axis indicates the first position with the highest histone modification level within 2 kb of the gene transcription start site (TSS). The y-axis indicates the expression level ranking of the gene. For a direct comparison, only the expression-matched subsets of genes with low, medium and high expression are plotted here. The spearman rank correlation values are shown below the scatter plots (all P-values < 10-8).
Vavouri and Lehner Genome Biology 2012 13:R110 doi:10.1186/gb-2012-13-11-r110