Fig. 2From: Epigenetic modifications in muscle regeneration and progression of Duchenne muscular dystrophyBasic principles of epigenetic modifications. a Epigenetic mechanisms regulating gene expression via histone modifications. Chromatin transcription permissive histone modifications such as H3K9ac/H4K4ac (acetylation) and H3K4me3/H4K4me3 (methylation) are catalyzed by HATs and HMTs, while repressive, including H3K27me3, H3K9me2/3, H4K20me2/3 (methylation), and deacetylation, through the action of HMTs and HDACs. Histone modifications and enzymes catalyzing the corresponding reactions are marked with matching colors. b Epigenetic mechanisms regulating gene expression via DNA modifications. Methylation and demethylation of CpG islands in the promoter regions of genes cause gene silencing and transcriptional activation, respectively. DNMTs and the process of CpG demethylation are, respectively, color-matched to methylated and demethylated CpGsBack to article page