Onset of Homochirality in Cell Monolayers

Chirality is a feature of many biological systems and much research has been focused on understanding the origin and implications of this property. Most famously, sugars and amino acids that are found in nature are homochiral, meaning that chiral symmetry is broken and only one of the two possible chiral states is ever observed. Perhaps less well-know, something similar is the case for certain types of cells too. They show chiral behavior and only one of the two possible chiral states is observed in nature. Understanding the origin of cellular chirality and what, if any, use or function it has in tissues and cellular dynamics is still an open problem and subject to much (recent) research. For example, cell chirality has already been shown to play an important role in drosophila morphogenesis.

Here, we develop a simple model to describe the possible origin of homochirality in cells.

Building on previous works by Jafarpour et al. [1] and Vicsek et. al. [2], we investigate how a homochiral state might have evolved in cells from an initially symmetric state without any mechanisms that explicitly break chiral symmetry. We find that noise, both on the level of flocking and on the level of cell division, is an important factor determining if and when a homochiral state is reached. We study how the competition between cooperative behavior and noise affects the transition to homochirality as well as the influence of cell death and cell division rates.

[1] Jafapour et al., PRL 115 (15), 2015

[2] Vicsek et al., PRL 75 (6), 1995