Three mice in Duke genetic research Dr. Randy Jirtle's lab should look the same. They are genetically identical, but one has brown fur and is smaller. The other two are primarily yellow-colored.
Jirtle said epigenetics is the reason for the difference, saying "this is one of the reasons why identical twins are not identical."
During pregnancy, the brown mouse's mother got supplements of folic acid, choline and other nutrients. The mothers of the blond mice did not. The blond mice are fatter and more prone to develop disease than the brown mouse.
"When you supplement with folic acid in this system, you protect against cancer, diabetes, obesity and, if you want to think of it this way, you protect against the animals being blond. They become brunettes," Jirtle said.
Jirtle said it is more proof that epigenetics, the ability to change a gene's expression, for better or worse, is real.
Dr. David Schwartz, director of the National Institute for Environmental Health Science based in the Research Triangle Park, said epigenetics has been shown to have a profound effect on the risk of developing cancer.
NIEHS is funding epigenetic research across the country, including Duke Medical Center. They want to find out what environmental factors, like nutrients and chemicals, can influence a gene's normal function.
"If we can understand the factors that affect the activity of a gene, we could probably have a big influence on the risk of developing disease," Schwartz said.
Schwartz said understanding epigenetics could lead to ways to reverse disease risk, which could mean fewer people would die from things like heart disease, lung disease or suffer from problems like asthma, arthritis or autism. It will take years of research to define the human epigenome before that dream becomes reality.
Researchers believe epigenetic characteristics can be passed down, mostly through the mother, as far as four generations.