An IFOD last week (found here: mapping-the-genome) covered some basics of DNA, genes and mapping the genome. Today is related, and concerns epigenetics.
Epigenetics merely refers to modification of an organism due to the how genes express themselves rather than a modification of the genetic code itself. It’s a change of phenotype without a change in genotype. In other words, while your genes provide your genetic code, epigenetic changes cause genes to turn themselves off and on. A great quote by Siddhartha Mukherjee summarizing epigenetics: “An organism’s individuality, then, is suspended between genome and epigenome.”
An interesting example of epigenetics is found in how rats rear their young. From the University of Utah: “Some mother rats spend a lot of time licking, grooming, and nursing their pups. Others seem to ignore their pups. Highly nurtured rat pups tend to grow up to be calm adults, while rat pups who receive little nurturing tend to grow up to be anxious. It turns out that the difference between a calm and an anxious rat is not genetic, it’s epigenetic. The nurturing behavior of a mother rat during the first week of life shapes her pups’ epigenomes. And the epigenetic pattern that mom establishes tends to stay put, even after the pups become adults.”
Why is this relevant? Most cancers, many types of cognitive dysfunction, cardiovascular disease, and neurobehavioral illnesses have all found to be a result of epigenetic changes.
What sort of things drive epigenetic changes?
- External “agents” such as heavy metals, pesticides, diesel exhaust, tobacco smoke, polycyclic aromatic hydrocarbons, hormones, radioactivity, viruses and bacteria;
- Lifestyle factors such as diet, exercise, stress, sleep
Thus, your genetics are not (usually) your destiny. External factors and lifestyle factors can influence the expression of some of your genes, both positively and negatively.
The study of epigenetics is a hot field in science and a great deal of research is being directed at basic research relating to what causes epigenetic changes as well as looking at epigenetic based therapies for disease.