The packaging of DNA into chromatin (image credit: Felsenfeld and Groudine, Nature 2013
If stretched out end to end, the DNA in just one cell of your body would reach a whopping six feet in length. A complex cellular structure called chromatin – made up of coils upon coils of DNA and protein – makes it possible to fit all that DNA into a single cell nucleus that’s only 0.0002 inches in diameter.
Chromatin: more than meets the eye
Once thought to merely play a structural role, mounds of data have shown that chromatin is also a critical regulator of gene activity. In fact, it’s a key component to maintaining a cell’s identity. So, for example, in the nucleus of a skin cell, genes related to skin function tend to lie within stretches of DNA having a loosely coiled chromatin structure. This placement makes the skin-related genes physically more accessible…
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