The coincidences of histone modification sites in the lymphoblastoid cell line, GM06990. (A) The frequency of occurrences of overlapping histone modification sites. The histogram shows the distribution of each type of overlapping histone modification site expressed as a percentage. Histone sites were defined as overlapping if they occurred within a 5-kb window centered on the site. Combinations are indicated as a five-digit binary code where 1 and 0 represent the presence or absence of each modification at a site, respectively, in the order H3K4me1:H3K4me2:H3K4me3:H3ac:H4ac. Combinations for which no sites were found are not shown. (B) Pie chart of occurrences of overlapping histone H3K4 methylation sites. (C) Box plot showing the distribution of distances to the nearest transcriptional start site (TSS) for the main combinations of histone H3K4 methylation sites. The box and horizontal line show the interquartile range and median of the data, while the whiskers extend to 1.5× the interquartile range of the distribution with open circles being the outliers of the distribution of distances from the TSS for each modification pattern.
