Berlin 2015 – scientific programme

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BP: Fachverband Biologische Physik

BP 53: Complex Fluids and Soft Matter (joint BP/DY/CPP)

BP 53.6: Talk

Friday, March 20, 2015, 11:00–11:15, H 1058

Bridging the scales: How is the large-scale deformation of a cellular network related to cell-scale processes? — •Matthias Merkel¹, Raphael Etournay², Suzanne Eaton², and Frank Jülicher¹ — ¹MPI for the Physics of Complex Systems, Dresden — ²MPI of Molecular Cell Biology and Genetics, Dresden

We propose a method to study the deformation of two-dimensional cellular networks. To this end, we focus on biological tissues, which typically undergo large-scale deformations during the development of an organism. However, how these large-scale deformations correspond to the collective behaviour of individual cells is not fully understood yet. Today, experimentalists are able to image tissues with up to 10 000 cells at sub-cellular spatial resolution and at a time resolution of minutes. Nevertheless, there is still a lack of methods allowing us to exploit the full depth of this huge amount of information.

Here, we propose a geometrical framework that exactly decomposes large-scale deformations into contributions by different kinds of cellular processes, which comprise cell shape changes, cell rearrangements (T1 transitions), cell divisions, and cell extrusions (T2 transitions). As the key idea, we introduce a tiling of the cellular network into triangles. This allows us to define the precise contribution of each of kind of cellular process to large-scale deformation. Additionally, our rigorous approach reveals subtle effects of correlated cellular motion, which constitute a novel source of large-scale tissue deformation. Finally, we demonstrate our new method on the wing of the fruit fly, which undergoes large-scale deformations during development.