You know that DNA carries information about your hair and eye color, height, body type, tendencies toward certain diseases, and numerous other characteristics. A new field in genetic studies, called epigenetics (the prefix epi- is Greek for “over,” “outer,” or “above”), examines inheritable traits that are not caused by changes in the DNA code.
For some time, scientists have known that compounds called methyl groups attach to genes to direct their expression as certain types of cells. Later, these methyl groups were shown to attach not just before birth, but also later in life. For example, exposure to certain chemicals could eventually cause cancer, owing to the actions of methyl groups. Further study showed that these changes could be passed from one generation to the next, just like a gene mutation. Now a radical proposal has emerged—that certain experiences can also affect methyl groups that set off changes to the DNA inside a person’s brain cells, and those changes can be expressed in behavioral or emotional difficulties. Moreover, those changes can be passed down to offspring. Welcome to behavioral epigenetics, a whole new field of inquiry. Experiments are demonstrating that behavioral epigenetics may provide new insights into mental illness and its treatment.
If DNA can pass information about emotional traumas down through generations, who might be passing on these changes? The possibilities are many, unfortunately. They may include great-grandparents who suffered terribly during the Holocaust, refugee immigrants who survived wartime horrors in their homelands, or anyone who suffered from severe abuse or neglect at the hands of alcoholic or drug-addled parents. There is good news, however. Experiments indicate that the guilty methyl groups at the heart of the problem can be removed by medication. In addition, attentive, loving care can also dilute the influence of the insidious methyl groups. So, DNA—even traumatized DNA—is not destiny.
Image credit: © Houghton Mifflin Harcourt
- Ghost in Your Genes
Follow the links to watch videos and see diagrams of epigenetics at work.
(Source: PBS; accessed April 30, 2013)
- Behavioral Epigenetics
Get the bare bones of the discovery and mechanisms of behavioral epigenetics.
(Source: Wikipedia; accessed April 30, 2013)
- Are Your Genes Your Destiny? (Not If Your Mom Has Anything to Say about It)
Meet the three men at the forefront of epigenetics research and learn more about their findings.
(Source: McGill University News, Spring–Summer 2011)
- Chemical Defects “Last Generations”
Exposure to certain chemicals during pregnancy can cause changes that are passed through generations.
(Source: BBC News, January 25, 2013)