The Epigenome

DNA is only half the story of the instructions for building all the parts of the body. DNA is wrapped around proteins called histones, both dna and histones are covered with tags, the second layer of this structure is called the epigenome. 

Tags are a profile with specific gene expression instructions and act as a type of cellular memory. These tags react to signals from the outside world.The epigenome is “flexible” meaning it can change in order to turn certain proteins off or on. Epigenetic tags, react to signals from the outside world, (for example, diet or stress) and adjust specific genes in response to these signals. Epigenetic tags act as an example of cellular memory. A cell's epigenetic profile embodies a collection of tags that instruct genes whether to turn on or off.

Epigenome vs. Genome: What's the difference?

Basically, the epigenome is flexible whereas the genome is not.

A genome is your genetic makeup based on DNA when you are born. As you begin to age, your epigenome begins to change, this is based on your environment, as well as the way your DNA transfers throughout your body.