Alladi Ramakrishnan Hall

Is the packing of cells important for tissue morphogenesis?

Ankit Agrawal

Weizmann Institute of Science, IL

Packing of objects (or particles) is a fascinating problem to understand the nature of the material and its mechanical responses to bulk. Packing is ubiquitous and studying from decades to understand the microstructure and bulk properties of liquid, glasses, crystals as well as granular matter but not much in the context of biological tissue. Recent experiments show that tissue morphogenesis requires the collective, coordinated motion and deformation of a large number of cells [1]. Cells coordinate their behaviours during various biological processes such as; embryogenesis, tumorigenesis, and tissue remodelling, and this coordination largely depends on the mechanical properties of the external environment. In contrast to single cells, collective cell behaviours rely on the cellular interactions not only with the surrounding extracellular matrix but also with neighbouring cells [2]. Cells interacting with neighbours are spatially constraint and can be seen from a packing problem too. In general, such systems show disordered packing which is a cause of structural imperfection and requires a statistical description to quantify the randomness through the distributions of local parameters, such as the coordination number, neighbour number, packing fraction, the cell shape parameter and the cell volume. We will show from growth plate tissue that how such statistics of cell packing changes across different regime and might give some explanation about the involvement of packing in morphogenesis.

[1] Silvanus Alt et al. "Vertex models: from cell mechanics to tissue morphogenesis", Philos Trans R Soc Lond B Biol Sci. 2017