All Eyes

From antelopes to zebrafish, aardvarks to zebus and all the vertebrates in between – including us – you’ll find rounded eyeballs are a common feature. But how does this shape come about? The precursor to vertebrate eyes is the optic vesicle, a developing tissue with two layers: an outer layer of retinal pigmented epithelium (RPE) and an inner layer of neural retina. Neural retina is known to create mechanical forces that help curve the optic vesicle into an optic cup. Researchers now investigate whether RPE cells also contribute, using zebrafish whose RPE cells are genetically engineered to fluoresce. Live-cell fluorescence microscopy of zebrafish embryos (pictured) revealed RPE cells (green) flattening and stretching out to cover the whole neural retina. Preventing this flattening by adding a chemical that interfered with the cells’ architecture stopped the optic cup from becoming curved. RPE is, therefore, also essential in creating the rounded shape of our eyes.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Video from work by Tania Moreno-Mármol and colleagues
• Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Campus de la Universidad Autónoma de Madrid, Madrid, Spain
• Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, September 2021