SMART NEWS

Chromosomes Aren’t Actually X Shaped

So much for all that memorizing you did in high school

Contributor

September 26, 2013

Imagine a chromosome. You’re probably picturing a nice little X shape, aren’t you? That’s probably what your high school science teacher taught you, anyway. Well, it turns out that’s not actually what chromosomes looks like.

A recent Nature paper included 3D pictures of chromosomes, revealing their internal structure. Here’s what they really look like, according to the Biotechnology and Biological Science Research Council (BBSRC):

At the Verge, Katie Drummond explains how the images of the chromosomes were generated:

To create them, researchers first collected thousands of measurements of chromosomes, before combining them using computer modeling software. The resulting images show the precise shapes of chromosomes as they most often appear: more like blobs than X shapes (chromosomes do, however, take on an X shape during cell division). The models are also detailed enough to indicate the complex folding patterns of DNA and even map specific genes.

The BBSRC spoke with Peter Fraser, one of the researchers behind the new work, who said, “The image of a chromosome, an X-shaped blob of DNA, is familiar to many but this microscopic portrait of a chromosome actually shows a structure that occurs only transiently in cells – at a point when they are just about to divide.” So much for all that memorizing you did in high school.