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Spontaneous shear flow in confined cellular nematics.
G Duclos1, C Blanch-Mercader1, V Yashunsky1
1Laboratoire PhysicoChimie Curie, Institut Curie, PSL Research University - Sorbonne Universités, UPMC - CNRS. Equipe labellisée Ligue Contre le Cancer ; 75005, Paris, France.
Nature Physics
|August 7, 2018
Summary
Spindle-shaped cells in confined tracks spontaneously generate shear flows, with flow characteristics dependent on stripe width. A critical width transition, explained by active gel theory, governs cell alignment and flow behavior.
Area of Science:
- Biophysics
- Cell Biology
- Soft Matter Physics
Background:
- Collective cell migration is crucial in embryonic development and tumor evolution.
- Antiparallel cell displacements within confined tracks can lead to shear flows, but underlying mechanisms are unclear.
Purpose of the Study:
- To investigate the mechanisms driving spontaneous shear flows in collective cell migration.
- To understand how microenvironmental confinement, specifically stripe width, influences cell behavior and flow dynamics.
Main Methods:
- Experimental observation of spindle-shaped cells migrating on stripes of varying widths.
- Development and application of a hydrodynamic active gel theory.
Main Results:
- Cells on wide stripes self-organize into a nematic phase with edge shear flows.
- On narrower stripes (below a critical width), cells align with the stripe, and net flow vanishes.
- The transition between flowing and non-flowing states is identified as a Fréedericksz transition.
Conclusions:
- Cellular activity and confinement width dictate collective cell migration patterns and flow generation.
- Active gel theory provides a framework for understanding spontaneous antiparallel cell displacements.
- The findings offer a generic mechanism applicable to in vivo cell movement.
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