Epigenetics: How Genes and Environment Interact

Author: Randy Jirtle, Ph.D., Duke University. Human epidemiological and animal experimental data indicate that the risk of developing adult onset diseases and neurological disorders is influenced by persistent adaptations to prenatal and early postnatal environmental exposures. One group of epigenetically regulated genes that potentially links environmental exposures early in development to adult diseases are those with metastable epialleles. These genes have highly variable expression because of stochastic allelic changes in the epigenome rather than mutations in the genome. The viable yellow agouti (Avy) mouse harbors a metastable Agouti gene because of an upstream insertion of a transposable element. We have used the Avy mouse to investigate the importance of epigenetic alterations in determining adult disease risk in response to early developmental exposure to both chemical and physical agents. The importance these studies with regards to human health and disease will be discussed.