Epigenetics are structural adaptations of chromosomal regions that register, signal, or perpetuate altered activity states (7). Epigenetic modification includes histone acetylation, methylation, ubiquitination, phosphorylation, and sumoylation; DNA methylation; and chromatin remodeling (12). These epigenetic marks not only regulate intrinsic gene expression, but can also be passed through dividing cells or gametes as epigenetic memory to regulate gene expression of daughter cells or progeny (6). Thus, epigenetic modification has a pronounced role in influencing cell fate and phenotypes of differentiating cells.
