What is epigenetics?

Epigenetics is the study of heritable phenotypic changes that are governed by mechanisms controlling gene expression such as post-translational modification of histones and DNA methylation, but that do not involve alterations in the genetic code.

Heritable phenotypes are intuitively related to transgenerational phenotypic changes occurring at the organism level but can also relate to changes that occur within subpopulations of cells. For example, during cellular differentiation, cell characteristics undergo dramatic and stable changes in their characteristics. Similarly, cancerous cells completely change their behavior to become more aggressive or to develop drug resistance. Both cellular differentiation and cancer progression are to a large extent governed by epigenetic mechanisms.

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Lamarck model for
epigenetic transgenerational inheritance

What is DNA methylation and why is it an important epigenetic mechanism?

DNA methylation is the covalent addition of a methyl group to a cytosine generally located next to a guanine residue and is associated with gene repression. A dedicated mechanism maintains DNA methylation patterns throughout cell division. Thus, DNA methylation is thought to be the most stable and heritable epigenetic marks. Alterations in DNA methylation patterns are known to be crucial for cell differentiation
and for cancer development.

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What is epigenetic editing?

Much like genetic editing, epigenetic editing aims to modify epigenetic patterns to activate or repress gene expression. Epigenetic editing can be employed to improve our understanding of physiological processes and to develop treatments for various diseases. The advantage of epigenetic editing over genetic editing is that it does not modify the actual DNA sequence, thus circumventing the risk of creation of new genetic aberrations.

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