Genetic information is stored in DNA as a sequence of specific base pairings. This is passed on largely unchanged from one generation to the next. But how is it possible that cells differ so massively in form and function, such as in the blood, nerves, skin or teeth, even though they have all the same genetic material (genome)? This is where “epigenetics” comes into play. This primarily refers to chemical changes in our genome that ultimately influence whether and how a cell can access its genetic material. In other words, epigenetic mechanisms determine when which gene is active or inactive. Among the most important epigenetic changes are DNA methylation and the alteration of specific genome-associated proteins (histones). Such changes are also referred to as the epigenome. In contrast to the genome, the epigenome can be rapidly adjusted in response to changes (e.g., environmental factors). Research on the epigenome therefore focuses on the mechanisms that control the activity of genes without altering the base sequence of DNA.
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Source: Phys.org