Layering Up

As you’re reading this text, light is streaming into each eyeball and landing on the retina – the layer of specialised nerve cells at the back of the eye that detect light and send signals into your brain where they’re interpreted as words and pictures. These layers are easy to see in these microscope images of mouse retinas that have been stained with fluorescent dyes highlighting different types of cells. But how does each type of cell know which layer it belongs to? To find out, researchers have been creating genetically engineered mice lacking molecules known as protocadherins, which help cells to sort themselves out and stick together. The panels in the left-hand column come from a healthy animal, while the others are from animals with faulty versions of two different protocadherins. By carefully comparing the results, scientists are starting to understand how these complex nerve cell layers are assembled.

Written by Kat Arney

Kat Arney

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Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Image adapted from work by Andrew M. Garrett and colleagues
• The Jackson Laboratory, Bar Harbor, ME, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in PLOS Genetics, December 2019