section_path: Exercise-trained effects are mediated by epigenetic mechanisms/Exercise-induced regulation of genes in muscles
section_name: Exercise-induced regulation of genes in muscles
paragraph_text: Exercise-induced regulation of genes in muscles
  
  Gene expression in muscle is largely regulated, as in tissues generally, by regulatory DNA sequences, especially enhancers. Enhancers are non-coding sequences in the genome that activate the expression of distant target genes, by looping around and interacting with the promoters of their target genes (see Figure "Regulation of transcription in mammals"). As reported by Williams et al., the average distance in the loop between the connected enhancers and promoters of genes is 239,000 nucleotide bases.