The genetic blueprint, or DNA, within all of the cells in our bodies is identical. However, there are hundreds of different types of cells that we are made of, and each of these cell types works in a diffferent way. How does the same DNA tell one group of cells to perform the functions of neurons (brain cells), and tell another group of cells to perform the functions of the small intestine? The DNA indeed has all of this information stored within its sequence, but the DNA by itself is not able to tell which parts of the blueprint need to be used at the right places and times to perform the different functions that make up all of the specialized functions required to make our bodies work.
"Epigenetics" literally means "above genetics", and most commonly refers to the addition of small chemical groups to the proteins around which the DNA is wrapped (chromatin modifications), or that are added directly to the DNA sequence itself (DNA methylation). These small chemical groups help to direct the DNA in how it is used - at the right place and time - to make our cells work together in allowing our bodies to function normally.
But what happens if something changes the way these chemical groups are added or removed? Can environmental exposures, like tobacco smoke, change how these chemical groups are able to control the way our DNA functions?
Here is a short video to help explain more about epigenetics and another about why we think this is so important to study in the NiCHES Children's Center (coming soon).