Minute to Understanding June 27, 2018

What is epigenetics?

By Dayana Krawchuk, Ph.D.

Learn how epigenetic changes can affect an individual — without physically changing their DNA sequence.

Genetics is your genes. And each gene has a unique sequence that makes a protein that does something in your body.

A genetic mutation is a hardcopy change in one or more parts of that sequence.

This could just make you, you. Or it could contribute to a genetic disease.

An epigenetic change also changes a gene’s DNA — but not at the sequence level.

Instead, special marks are added or removed to change how a protein works in the body. How these marks appear is a hot research topic. Some causes may be diet, stressors or environmental pollutants.

What’s important about epigenetics is that it offers a different approach to treating disease. Whereas a hardcopy genetic mutation is difficult to fix, finding ways to remove a bad epigenetic mark, or add a good one, could be an easier solution.

How can two mice with the same DNA sequence have different coat colors? Epigenetics! In this particular yellow mouse strain, when a mother is given a diet enriched in folic acid (a good source for epigenetic ‘methylation’ of DNA), a gene controlling coat color is methylated resulting in more brown pups being born than yellow. This is an example of how diet can cause epigenetic changes to affect an individual — without physically changing their DNA sequence. Illustration by Zoë Reifsnyder.