Epigenetics of Genes Displaying High and Preferential Expression in Myoblasts

Our analysis suggests that some of the hypermethylated DMRs repress cryptic, alternative, or adjacent promoters. Myoblast hypermethylated DMRs may also downmodulate expression in myoblasts to avoid yet higher RNA levels found in adult or fetal skeletal muscle tissue. The epigenetic insights that were obtained can help elucidate the transcription regulation of some of these genes (e.g., <i>MUSK</i>, <i>RAPSN</i>, <i>HEYL</i>, <i>SYNPO2</i>, <i>SYNPO2L</i>, <i>STAC3</i>, <i>PITX2</i>, and <i>TPPP3</i>) that are implicated in congenital myasthenic syndromes, myasthenia gravis, muscle repair, heart dysfunction, or cancer. This study supports cell type-specific roles for DNA hypo- and hypermethylation as a modulator of transcription levels, in addition to being an on-off switch during differentiation.