Cells and Tissues as Active Matter

Abstract

In this thesis, we use mathematical models of active matter, matter composed of particles
that consume energy, to gain insight into the dynamics of cells and tissues and to the
biological control mechanisms employed during development. Cells and tissues are powered
by myosin II molecular motors that convert chemical energy stored in high energy molecular
bonds to mechanical energy. Myosin II propagate stress throughout cells and tissues by coupling
to elongated proteins known as F-actin that provide scaffolding and structure in cells. In cells
and tissue, these stresses can be organised to generate systematic motion and affect material
properties, e.g. whether the tissue is hard or soft. There are a large number of biophysical
phenomena that are fascinating and that we do not fully understand, and we only touch on a
few of them here. Following the first two chapters, which are introductory and cover the relevant
biological and mathematical background, the research described in this thesis is split into two
parts. In part I, we study the effect of external forces and confinement on single cell motion, and
in part II, we study a type of tissue flow known as convergence-extension, which is a systematic
self-regulated elongation of tissue that occurs across many species during development.

Date of Award	5 Dec 2023
Original language	English
Awarding Institution	University of Bristol
Supervisor	Tanniemola B Liverpool (Supervisor) & Silke E Henkes (Supervisor)