26 Sep 2013
You’d be forgiven for thinking that all chromosomes are X-shaped bundles. But new research MRC-funded research has shown that they spend most of their time looking more like a tangled mass of string, as Peter Fraser, a researcher at the Babraham Institute, explains.
The image of a chromosome as an X-shaped blob is familiar to many. But perhaps not everyone knows that this microscopic portrait of a chromosome shows a structure that occurs only transiently in cells, at a point when they are just about to divide by undergoing a process called mitosis.
The vast majority of cells in an organism have finished dividing and their chromosomes don’t look anything like the familiar X-shape. Even cells that are still in the business of dividing, such as blood and skin cells, spend most of their time in a kind of ‘resting’ non-mitotic state. But what do chromosomes in these cells look like?
So far it has been impossible to create accurate pictures of these chromosomes — existing techniques can only determine the average structure of chromosomes from millions of cells. But it’s important that we know what they look like because, far from resting, it’s in this non-mitotic state that all of the important functions of the genome are operating and controlled. [...]