A minimal mechanically consistent model of smoothly dividing disk-shaped cells

Area of Science:

• Physics
• Biophysics
• Computational Biology

Background:

• Cell division is fundamental to life, driving dynamics in various biological systems.
• Particle-based models are used to study emergent dynamics, but struggle with mechanical consistency during cell division.
• Aberrant mechanical fluctuations during division hinder meaningful analysis in existing models.

Purpose of the Study:

• Introduce a minimal, mechanically consistent model for cell division in particle-based simulations.
• Ensure force continuity during cell division for accurate mechanical analysis.
• Provide a framework for studying collective cell behaviors and mechanical observables.

Main Methods:

• Developed a model where cells are represented by two nodes forming overlapping disks that separate during division.
• Ensured force continuity through internal degrees of freedom, cell-cell interactions, and equations of motion.
• Translated an established spherocylinder model into the new framework for benchmarking.

Main Results:

• Demonstrated force continuity in the new disk cell model through numerical simulations.
• Quantified improvements in mechanical consistency compared to previous models.
• Showed agreement in collective behaviors like alignment and orientational order.
• Successfully extracted forces and performed Voronoi-based interpretation in confluent tissues.
• Provided a 3D generalization for embryonic-like confinement.

Conclusions:

• The new model ensures mechanical consistency during cell division, overcoming limitations of previous approaches.
• It provides a robust framework for analyzing mechanical observables like velocities and stresses in biological systems.
• The model is readily extensible for incorporating additional biological features and is available as an open-source Julia package.