Centre for Mathematics Medicine and Biology Seminar

Alexander Nestor-Bergmann, University of Cambridge

Title: Mechanical characterisation of geometrically complex tissues within a discrete framework

Abstract:

There is strong evidence that mechanical cues are used to control many cell behaviours. However, our understanding of these behaviours is limited by the difficulty in characterising the mechanical properties of geometrically complex tissues. Working in the context of a popular vertex-based model, expressions for the linearised relation between tissue-level stress and strain about a deformed base state can be derived as a direct sum over all cells.

This framework shows that mechanically homogeneous tissues can exhibit anisotropic mechanical properties. The model captures observations of an epithelium from a Xenopus embryo, where uniaxial stretching induces spatial ordering. In a stretched tissue, cells under net tension (compression) tend to align with (against) the direction of stretch, but with the stress remaining heterogeneous at the single-cell level. Expressions for the elastic tissue moduli predict that tissue properties can be tuned to a regime with high elastic shear resistance but low resistance to area changes, or vice versa.

We will discuss how this theoretical framework can provide mechanistic insights into fundamental cell behaviours, such as cell division.