Unstable shapes of dividing cells
Date posted: 25.08.11 11:09, Age: 271 days
By: Florian Frisch
MPI-CBG researchers show drastic instabilities and oscillations
 A theoretical model based on a competition between cortex turnover and contraction dynamics accurately accounts for the oscillations.
Cell division, the process by which a cell gives rise to two daughter cells, is central to life. Each of the cells in our body is the result of a great number of divisions, which started with a single cell: the fertilized egg. Anomalies in division are a hallmark of tumor cells. How cells divide has fascinated biologists and physicists for over a century. Cytokinesis, the physical process by which a spherical cell cuts itself into two, occurring at the very end of cell division, has particularly drawn the attention of biophysicists, as it involves a striking series of cell shape changes, all of which must be precisely mechanically orchestrated.
Researchers from the MPI-CBG, in collaboration with a theorist at the Max Planck Institute of the Physics of Complex Systems (MPI-PKS), now report that the shape of a dividing cell is intrinsically unstable. By combining biophysical experiments and physical modeling, they show that mechanical forces exerted at the surface of the future daughter cells can lead to drastic shape instabilities and oscillations. Such instabilities compromise the symmetry of the shape of the dividing cell and, if they are not dampened, lead to division failure. They propose a mechanism by which cells can prevent such instabilities by continuously releasing the tension exerted at the surface of the future daughter cells into bubble-like protrusions called blebs.
original paper:
Jakub Sedzinski, Maté Biro, Annelie Oswald, Jean-Yves Tinevez, Guillaume Salbreux & Ewa Paluch:
Polar actomyosin contractility destabilizes the position of the cytokinetic furrow
Nature 476, 462–466 (25 August 2011)
doi:10.1038/nature10286
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