A reaction telegraph model reveals synergy between motility strategies in Myxococcus xanthus predation

Area of Science:

• Microbiology
• Mathematical Biology
• Biophysics

Background:

• Myxococcus xanthus employs two motility systems: adventurous and social.
• Social motility is associated with bacterial clusters, while adventurous motility is for isolated cells.
• Understanding the interplay of these systems is key to predatory invasion dynamics.

Purpose of the Study:

• To model the predatory invasion of Myxococcus xanthus, focusing on the synergistic effects of adventurous and social motility.
• To extend existing reaction-diffusion models by incorporating persistent cell motion and population structuration.
• To investigate the transition from normal to anomalous speed and the dynamics of pulled and pushed fronts.

Main Methods:

• Development of a transport-reaction model incorporating persistent cell motion and clustered populations.
• Analysis of the linear regime to identify transitions from normal to anomalous speed.
• Numerical simulations to study nonlinear dynamics, including pulled and pushed front transitions.
• Model modifications to reproduce experiments with motility mutants.

Main Results:

• The model predicts a transition from normal to anomalous speed in the linear regime, consistent with hyperbolic model characteristics.
• Numerical simulations reveal transitions between pulled and pushed fronts in the nonlinear regime.
• The model successfully reproduces experimental results from Myxococcus xanthus mutants lacking specific motility apparatuses.
• Synergistic effects between the two motility systems are rationalized.

Conclusions:

• The proposed transport-reaction model provides a framework for understanding Myxococcus xanthus predatory invasion.
• The study elucidates the complex dynamics of bacterial population waves, linking motility mechanisms to collective behaviors.
• Findings offer insights into the precursors of biofilm formation and bacterial collective behaviors.