Chromatin immunoprecipitation (ChIP)-Seq specific for histone 3 lysine 27 acetylation (H3K27Ac) and histone 3 lysine 4 di-methylation (H3K4Me2) was performed after 0, 3, 12 and 24 h of butyrate treatment. (A) Megabase (Mb) coverage of histone acetylation (H3K27Ac, left) and methylation (H3K4Me2, right), using peak-calling parameter settings -size 1000 -minDist 2500. Donor 1 (D1) is indicated in blue and donor 2 (D2) is indicated in red. Overlap between the donors is indicated by the shared bars (yellow). (B) Genomic annotation of H3K27Ac peaks in untreated human mast cells (upper donut graph) and redistribution of acetylation peaks induced by 3, 12 and 24 hours of butyrate treatment (lower donut graphs).