Ghost in Your Genes--TV Program Description
The "something else" turns out to be a network of chemical switches that sit on our DNA, turning genes off and on. Called collectively the epigenome, the switches appear to play a major role in everything from how our cells keep their identity to whether we contract dread diseases. Epigenetic switches may even help mold our personalities—or so it appears to Canadian researchers studying a group of epigenetically modified rats.
"We're in the midst of probably the biggest revolution in biology, which is going to forever transform the way we understand genetics, environment, the way the two interact, and what causes disease," says Mark Mehler, Professor of Neurology at Albert Einstein College of Medicine. "It's another level of biology, which for the first time really is up to the task of explaining the biological complexity of life."
Might these effects be epigenetic? Might our experiences, by changing our epigenomes, literally change the fate of our offspring ... and their offspring ... and theirs in turn? And might our own states of health owe something to the diets and exposures of our forebears?
Some researchers are already convinced. "You live your life as a sort of ... guardian of your genome," says Marcus Pembrey of the Institute of Child Health at University College London, a co-investigator in the Swedish study. "It seems to me you've got to be careful of it because it's not just you. You can't be selfish ... you can't say, 'Well, I'll smoke' or 'I'll do whatever it is because I'm prepared to die early.' You're also looking after it for your children and grandchildren...." Epigenetics, Pembrey says, "is changing the way we think about inheritance forever."
Ghost in Your Genes--Transcript
MARCUS PEMBREY: Olly first reported that the food supply of the ancestors was affecting the longevity or mortality rate of the grandchildren, so I was very excited.
MARCUS PEMBREY: It really did look as if there was some new mechanism transmitting environmental exposure information from one generation to the next.
NARRATOR: The diagram showed a significant link between generations, between the diet in one and the life expectancy of another.
MARCUS PEMBREY: We are changing the view of what inheritance is. You can't, in life, in ordinary development and living, separate out the gene from the environmental effect. They're so intertwined.
NARRATOR: And if a pesticide can generate such effects, what about stress, smoking, drinking? To some, the epigenetic evidence is compelling enough already to warrant a public note of caution.