Mellow or Stressed? Mom’s Care Can Alter DNA of Her Offspring

July 19, 2004 | Source: Wall Street Journal

Scientists have discovered that rat genes can be altered by the mother’s behavior.

All newborn rats have a molecular silencer on their stress-receptor gene, they found. In rats reared by standoffish mothers, the silencer remains attached, the scientists will report in the August issue of Nature Neuroscience. As a result, the brain has few stress-hormone receptors and reacts to stress like a skittish horse hearing a gunshot.

But licking and grooming by an attentive mother literally removes the silencer; the molecule is gone. Those baby rats have lots of stress-hormone receptors in their brains and less stress hormone, and they grow up to be curious, unafraid and able to handle stress.

Altering genes by adding or removing silencing molecules is part of a new field called epigenetics.