Leiden University Student Repository

Ernst, Jeremy (2019)

The mechanical interplay between cell shape and actin cytoskeleton organisation

Master thesis | Physics (MSc)

In this thesis, we investigate the mechanical interplay between a cell’s shape and its actin cytoskeleton organisation. We combine theoretical work with numerical simulations and experimental data to investigate this behaviour. The actin cytoskeleton is modelled using a liquid crystal framework and is combined with a model for the cell contour that has stress fibers apply a directed stress on the edge. We describe a feedback mechanism where the orientation of stress fibers is a competition between alignment with the cell edge and with one another, and where the shape of the cell edge is dependent on the contractile force exerted along the direction of the nearby stress fibers. We show that we can accurately reproduce the shape and anisotropic actin cytoskeleton structure of cells on micropillar arrays, as well as the emergence of topological defects.

Actin

Simulation

Cell shape

Liquid crystal

Nematic

Author

Ernst, Jeremy

Faculty

Faculty of Science

Specialisation

Research in Physics, Biological and Soft Matter Physics

Supervisors

Giomi, Luca

ECTS Credits

4

Language

en