PBS - New life for the ghost in your genes

Is DNA destiny? NOVA's Ghost In Your Genes, which will be rebroadcast this Tuesday on many PBS stations, provides fresh hope that our fate isn't inscribed in our genes.

A "second genome," or epigenome, which has only recently caught scientists' attention, can switch genes on and off with chemical tags. And though you can't rewrite your genes, you just might be able to change your epigenome.

How? Diet and exposure to toxins, like those in cigarettes, probably play a role. But Moshe Szyf and Michael Meaney, scientists at McGill University in Montreal, wanted to find out if a person's upbringing could influence his epigenome. Would abuse, neglect, and stress leave an imprint? Meaney and Szyf thought so, and set out to test their hypothesis on rat pups...