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10:52
Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets
Published on: August 13, 2016
Hydrostatic pressure and the actomyosin cortex drive mitotic cell rounding.
Martin P Stewart1, Jonne Helenius, Yusuke Toyoda
1ETH Zürich, Department of Biosystems Science and Engineering, CH-4058 Basel, Switzerland.
Nature
|January 4, 2011
Summary
During mitosis, cells generate outward rounding force driven by osmotic pressure. The actomyosin cytoskeleton maintains this force against external impediments, enabling cells to control shape and volume.
Area of Science:
- Cell biology
- Biophysics
- Cytoskeleton dynamics
Background:
- Adherent animal cells flatten during interphase and round during mitosis.
- Mitotic cell rounding is essential for cell division but the driving forces are unclear, especially within tissues.
Purpose of the Study:
- To investigate the forces driving mitotic cell rounding.
- To understand the roles of osmotic pressure and the actomyosin cytoskeleton in this process.
Main Methods:
- Utilized cantilevers to measure cell rounding force and volume.
- Observed changes in cell volume and force upon disruption or stimulation of the actomyosin cortex.
Main Results:
- Cells exhibit an outward rounding force that increases during mitosis.
- This force is generated by osmotic pressure and maintained by the actomyosin cytoskeleton.
- Actomyosin cortex disruption increases cell volume; contraction decreases it.
Conclusions:
- Mitotic cell rounding is driven by osmotic pressure balanced by actomyosin cortex contraction.
- Cells regulate volume, shape, and mechanical properties by modulating surface tension and osmotic pressure.
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