Beyond DNA: Epigenetics – Deciphering the link between nature and nurture

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Beyond DNA: Epigenetics – Deciphering the link between nature and nurture:

Photographed during the Dutch Hunger Winter, which lasted from the start of November 1944 to the late spring of 1945, a Dutch boy waits at a restaurant with a spoon tucked into his waistband. Epidemiologists have been able to follow the long-term effects of the famine on those who lived through it, and have even seen its effects in the next generation.

Kryn Taconis/Library and Archives Canada/PA-169941

Excerpted from The Epigenetics Revolution: How Modern Biology Is Rewriting Our Understanding of Genetics, Disease, and Inheritance, by Nessa Carey (Columbia University Press, 2012). Copyright © 2012 Nessa Carey.

We talk about DNA as if it’s a template, like a mold for a car part in a factory. In the factory, molten metal or plastic gets poured into the mold thousands of times, and, unless something goes wrong in the process, out pop thousands of identical car parts.

But DNA isn’t really like that. It’s more like a script. Think of Romeo and Juliet, for example. In 1936 George Cukor directed Leslie Howard and Norma Shearer in a film version. Sixty years later Baz Luhrmann directed Leonardo DiCaprio and Claire Danes in another movie version of this play. Both productions used Shakespeare’s script, yet the two movies are entirely different. Identical starting points, different outcomes.

That’s what happens when cells read the genetic code that’s in DNA. The same script can result in different productions. The implications of this for human health are very wide-ranging, as we will see from the case studies we are going to look at in a moment. In all these case studies it’s really important to remember that nothing happened to the DNA blueprint of the people in these case studies. Their DNA didn’t change (mutate), and yet their life histories altered irrevocably in response to their environments.

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via the Lab Tumblr: http://genefish.tumblr.com/post/40775806779