and not many authors yet on Bluesky except of course the fabulous @natalieadye.bsky.social

Taken together we show that 3D epithelial tissue morphogenesis in the Drosophila wing disc pouch during eversion is based on in-plane spontaneous strains generated by active cellular behaviours, and propose that this could be a more general mechanism for shaping animal tissues.
- The End - 11/11

We test the model, by perturbing MyoVI, for which we previously showed that it disrupts mechanosensitive feedback and probably affects oriented rearrangements. And we nailed it.
10/n

Using this model we found, that radial rearrangements and an inhomogeneous increase in cell area drive the shape change in the wing disc. This supports the idea of a mechanical pre-patterning because the cell area distribution and the radial bias in rearrangements arise from earlier stages.
9/n

To test the observed cell behaviours we build a 'simple' computational model based on a network of interconnected springs, in which - by a change in spring length - we can impose different measured deformations.
8/n

So how did we test this? We quantified the tissue shape change and cell shapes at different time points, and identified patterns of cell shapes using a topological coordinate system. Using topology also allowed us to infer the amount of oriented rearrangements from static images.
7/n

In our case, it means that the material (aka the tissue) undergoes pre-defined (genetics/ mechanics), local (the cells), in-plane (in the plane of the cell sheet) deformations, that create a tissue-wide geometric incompatibility with the initial shape (going from flat to curved).
6/n

So how do you get such a complex shape change? To answer this, we took inspiration from Material Sciences, more specifically from 'shape programmable materials'. These materials experience spontaneous strains, where the internal lengths change in response to stimuli in a desired way.
5/n

Why is this interesting? First, eversion is a large-scale (hundreds of cells) tissue shape change. Second, it is complex, as it undergoes curvature changes in different directions (unlike, for example, a one-directional change as in folding), and it is not radially symmetric (tubes, budding).
4/n

At the transition from larva to pupa, the wing disc undergoes a 3D shape change called wing eversion. Which we studied, focusing on the shape change of a subregion, the wing disc pouch (here in blue/grey).
3/n

In this paper, we tackle the 3D epithelial shape changes during Drosophila wing disc eversion. Wing what? - Briefly: Drosophila has different live phases: Embryo, Larva, Pupa and Adult. The future adult wing arises from the wing disc, which grows and morphs throughout the live of the fly.
2/n