PT  - JOURNAL ARTICLE
AU  - Anastasiya Trushko
AU  - Ilaria Di Meglio
AU  - Aziza Merzouki
AU  - Carles Blanch-Mercader
AU  - Shada Abuhattum
AU  - Jochen Guck
AU  - Kevin Alessandri
AU  - Pierre Nassoy
AU  - Karsten Kruse
AU  - Bastien Chopard
AU  - Aurélien Roux
TI  - Buckling of epithelium growing under spherical confinement
AID  - 10.1101/513119
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 513119
4099  - http://biorxiv.org/content/early/2020/02/17/513119.short
4100  - http://biorxiv.org/content/early/2020/02/17/513119.full
AB  - Many organs, such as the gut or the spine are formed through folding of an epithelium. This change in shape is usually attributed to tissue heterogeneities, for example, local apical contraction. In contrast, compressive stresses have been proposed to fold a homogeneous epithelium by buckling. While buckling is an appealing mechanism, demonstrating that it underlies folding requires to measure the stress field and the material properties of the tissue, which is currently inaccessible in vivo. Here we show that monolayers of identical cells proliferating on the inner surface of elastic spherical shells can spontaneously fold. By measuring the elastic deformation of the shell, we infer the forces acting within the monolayer and its elastic modulus. Using analytical and numerical theories linking forces to shape, we find that buckling quantitatively accounts for the shape changes of our monolayers. Our study shows that forces arising from epithelium growth in three-dimensional confinement are sufficient to drive folding by buckling.