Emergence of dynamic contractile patterns in slime mold confined in a ring geometry

TL;DR

This study investigates how slime mold extit{Physarum polycephalum} develops various stable contractile patterns in ring-shaped chambers, revealing that oscillation frequency is constant while wavelength scales with chamber size, informing models of cellular contractility.

Contribution

It provides a comprehensive inventory of contractile patterns in slime mold confined in rings and analyzes their frequency and wavelength scaling, advancing understanding of cytoplasmic flow coordination.

Findings

Oscillation frequency is independent of ring perimeter.

Wavelength scales linearly with ring size.

Results support feedback mechanisms in contractile activity models.

Abstract

Coordination of cytoplasmic flows on large scales in space and time are at the root of many cellular processes, including growth, migration or division. These flows are driven by organized contractions of the actomyosin cortex. In order to elucidate the basic mechanisms at work in the self-organization of contractile activity, we investigate the dynamic patterns of cortex contraction in true slime mold \textit{Physarum polycephalum} confined in ring-shaped chambers of controlled geometrical dimensions. We make an exhaustive inventory of the different stable contractile patterns in the absence of migration and growth. We show that the primary frequency of the oscillations is independent of the ring perimeter, while the wavelength scales linearly with it. We discuss the consistence of these results with the existing models, shedding light on the possible feedback mechanisms leading to coordinated contractile activity.