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Randy L. Jirtle, Ph.D. Background: We've all heard the saying "You are what you eat," but recent research from Duke University scientists suggests "You are what your mother ate" too. In a study of nutritional effects on development, this team showed they could change coat color of baby mice simply by feeding their mothers four common nutritional supplements before and during pregnancy and lactation. These four supplements also lowered the susceptibility of obesity, diabetes, and cancer in the offspring. Advance: Pregnant laboratory mice that were fed vitamin B12, folic acid, choline, and betaine gave birth to babies predominantly with brown coats. Offspring from pregnant mice not given the supplements had yellow coats. The non-supplemented mothers were not deficient in these nutrients-they received normal levels from their food. Molecular biology techniques demonstrated that the reason for the difference in coat color was a change in the expression of a specific gene called Agouti. The nutritional supplements were shown to methylate the gene and prevent its expression. Mice that over-express the Agouti gene tend to obese and susceptible to diabetes because the protein it encodes binds to a receptor in the brain and interferes with the signal to stop eating. Implication: Although the animals with the altered gene expression were healthier than the non-supplemented mice, this may not always be true. Methylation of genes, and subsequent reduced expression, could also produce deleterious effects depending on the specific gene altered. For example, methylation that occurs near or within a tumor suppressor gene can reduce its expression and therefore inhibit its anti-cancer activity. Further research is needed to understand the molecular effects of nutrients on cells, not just the obvious manifestations. Citation: Waterland RA and Jirtle RL. Transposalbe elements: targets for early nutritional effects on epigenetic gene regulation. Mol Cell Biol. 23(15):5293-5300. |
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