What is epigenetics?
Epigenetics is the study of how both the environment we live in and our personal behavior affects how our DNA is read and/or understood by our functional genes, this typically results in our genes being turned “on” or “off”. For example, an epigeneticist may study how smoking (a personal behavior) can affect how our functional genes read our DNA. In this instance, smoking may result in our functional genes misreading our DNA and ultimately causing inflammation in the body and increasing our risk of some cancers. It’s important to understand that unlike genetic changes, most epigenetic changes are reversible because they only affect how our DNA is read or understood by our bodies. They do not change our underlying DNA sequence.
What are epigenetic modifications?
Epigenetic modifications—sometimes called epigenetic changes—are the actual changes that may occur depending on the environment we live in and/or our personal behavior. The main type of epigenetic changes include DNA methylation, histone modifications, and modifications as a result of non-coding RNA. These modifications affect how our bodies understand or “read” our genes. They do not modify our underlying DNA sequence which is inherited from our parents.
How does epigenetics work?
The movie analogy by Nessa Carey is commonly used to explain epigenetics. In this analogy you can think of your life as a movie.
In this movie, your cells are the actors and actresses reading from the script.
The script would be your DNA. Just like a script, your DNA tells your cells (the actors) what to do or say.
The director in this scenario is epigenetics. He or she has the power to make changes to how the actors and actresses interpret and perform the script. The director does not change the script itself, but they’re able to change how it is presented. This is similar to how epigenetic changes do not change your DNA sequence, but rather it changes how your functional cells express the DNA sequence.
Just like how two directors may create totally different movies from the exact same script, so too can different people who’ve experienced different environmental and behavioural variables change how their bodies read the same DNA sequence.
What is an example of epigenetics?
A popular example of epigenetics is the effect smoking nicotine can have on our bodies. Research studies have shown that individuals who smoke have decreased levels of DNA methylation in their AHRR gene. In turn, this can lead to changes in how different proteins and receptors are expressed and trigger a miscommunication in our bodies, ultimately resulting in potentially higher levels of inflammation and increased risk of some cancers.