Spontaneous transitions between amoeboid and keratocyte-like modes of migration

TL;DR

This study demonstrates that mutated Dictyostelium discoideum cells can spontaneously switch between amoeboid and fan-shaped migration modes, revealing coexistence of distinct motility behaviors within individual cells.

Contribution

It provides experimental evidence of spontaneous, reversible mode switching in cell migration and adapts a phenomenological model to explain these dynamics.

Findings

Cells exhibit spontaneous switching between migration modes.

Switching is reversible and occurs within the same cell.

A reaction-diffusion model explains the observed behavior.

Abstract

The motility of adherent eukaryotic cells is driven by the dynamics of the actin cytoskeleton. Despite the common force-generating actin machinery, different cell types often show diverse modes of locomotion that differ in their shape dynamics, speed, and persistence of motion. Recently, experiments in Dictyostelium discoideum have revealed that different motility modes can be induced in this model organism, depending on genetic modifications, developmental conditions, and synthetic changes of intracellular signaling. Here, we report experimental evidence that in a mutated D. discoideum cell line with increased Ras activity, switches between two distinct migratory modes, the amoeboid and fan-shaped type of locomotion, can even spontaneously occur within the same cell. We observed and characterized repeated and reversible switchings between the two modes of locomotion, suggesting that they are distinct behavioral traits that coexist within the same cell. We adapted an established phenomenological motility model that combines a reaction-diffusion system for the intracellular dynamics with a dynamic phase field to account for our experimental findings.