PT  - JOURNAL ARTICLE
AU  - Tom P. J. Wyatt
AU  - Jonathan Fouchard
AU  - Ana Lisica
AU  - Nargess Khalilgharibi
AU  - Buzz Baum
AU  - Pierre Recho
AU  - Alexandre J. Kabla
AU  - Guillaume T. Charras
TI  - Actomyosin controls planarity and folding of epithelia in response to compression
AID  - 10.1101/422196
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 422196
4099  - http://biorxiv.org/content/early/2018/09/20/422196.short
4100  - http://biorxiv.org/content/early/2018/09/20/422196.full
AB  - Throughout embryonic development and adult life, epithelia are subjected to external forces. The resulting deformations can have a profound impact on tissue development and function. These include compressive deformations which, although hard to study in model systems due to the confounding effects of the substrate, are thought to play an important role in tissue morphogenesis by inducing tissue folding and by triggering mechanosensitive responses including cell extrusion and cell differentiation. Here, using suspended epithelia, we are able to uncover the immediate response of epithelial tissues to the application of large (5-80%) in-plane compressive strains. We show that fast compression induces tissue buckling followed by active tissue flattening which erases the buckle within tens of seconds. Strikingly, there is a well-defined limit to this second response, so that stable folds form in the tissue for compressive strains larger than ∼35%. Finally, a combination of experiment and modelling shows that the response to compression is orchestrated by the automatic adaptation of the actomyosin cytoskeleton as it re-establishes tension in compressed tissues. Thus, tissue pre-tension allows epithelia to both buffer against fast compression and regulate folding.