Understanding Ageing

Calorie restriction can extend lifespan in mammals, but the mechanism is not clear. Research by Prof Jean-Pierre Issa of Temple University suggests it works through epigenetics

What is epigenetics?

Our body has a single genome that we get from our father and mother. But we have more than 200 different cell and tissue types, all derived from a single blueprint, the genome. So how do you generate different tissues from one book or blueprint? The answer is a set of processes that we call ‘epigenetics’, because they work on top of genetics. They function like bookmarks that a cell uses to establish its cellular identity. They tell the heart, for example, which pages of the book it should use. We call them tags. Epigenetic tags can be molecules attached to DNA, or to the proteins around which DNA is wrapped, and just as you can sequence [read] the genome, you can sequence the entire ‘epigenome’.

How do these tags affect the ageing process?