the epigenetics revolution by nessa carey

And similar mechanisms apply to much of our behaviour. If we drink a lot of alcohol an enzyme that metabolises it becomes more active – 'upregulated' in the jargon. Much epigenetics revolves around nutrition. Genes don't just issue instructions: they respond to messages coming from other genes, from hormones and from nutritional cues and learning. The cell tells the DNA what to do just as much as the DNA instructs the cell: you can't have one without the other. But the fact is, he needed cells, and we still can't synthesis them. In 2010 the maverick biologist and entrepreneur Craig Venter announced that he had created life when he inserted an entirely synthesised DNA into a bacterial cell. After all, in cloning, if you suck out the nucleus of a cell and replace it with the nucleus of a completely different kind of creature, it will grow into an adult dictated by the new, injected nuclear DNA. The notion was that the genes were all and the cells that contained them were just off-the-peg bags. When the human genome sequence was announced in 2001 the rhetoric was highly charged: this is a scroll the book of life a huge encyclopaedia a sacred chain of code 3bn characters long.

The grounds for excitement stem from the fact that this old and frequently sterile dichotomy is now being fleshed out with real knowledge of how genes are controlled and how they respond to life situations. In short, epigenetics is where nature meets nurture. In all of these processes genes are modified slightly and act differently from that point on. Epigenetics is what happens when genes are actually in action: in the growth of the foetus, in responding to hormones and environmental stress, to learning, to maturation at puberty.

The epigenetics revolution by nessa carey