The term epigenetics is used to describe heritable genetic modifications that are not attributable to changes in the primary DNA sequence. Epigenetic modifications play a crucial role in gene expression, and thereby underpin the development, regulation, and maintenance of the normal cell. Lifestyle, nutrition, and environmental factors can all lead to epigenetic changes.
Two of the most commonly studied epigenetic modifications involve:
- Protein - DNA interactions (i.e., binding of proteins to DNA)
- Methylation of cytosine (C) nucleotides in the context of a CpG dinucleotide
Because the expression of miRNAs can impact epigenetic mechanisms, they can also contribute to epigenetic changes.