Balance of actively generated contractile and resistive forces controls cytokinesis dynamics.
Cytokinesis, the fission of a mother cell into two daughter cells, is a simple and dramatic cell shape change. Here, we examine the dynamics of cytokinesis by using a combination of microscopy, dynamic measurements, and genetic analysis. We find that cytokinesis proceeds through a single sequence of shape changes, but the kinetics of the transformation from one shape to another differs dramatically between strains. We interpret the measurements in a simple and quantitative manner by using a previously uncharacterized analytic model. From the analysis, wild-type cytokinesis appears to proceed through an active, extremely regulated process in which globally distributed proteins generate resistive forces that slow the rate of furrow ingression. Finally, we propose that, in addition to myosin II, a Laplace pressure, resulting from material properties and the geometry of the dividing cell, generates force to help drive furrow ingression late in cytokinesis.
Zhang
Wendy
W
Department of Physics, James Franck Institute, University of Chicago, Chicago, IL 60637, USA.
Robinson
Douglas N
DN
D000818:Animals; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D048749:Cytokinesis / Q000235:genetics / Q000502:physiology*; D004023:Dictyostelium / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D008840:Microfilament Proteins / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D024462:Myosin Type II / Q000378:metabolism; D015800:Protozoan Proteins; D013045:Species Specificity; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; D008840:Microfilament Proteins; D015800:Protozoan Proteins; C100414:RacE protein, Dictyostelium discoideum; C101109:ctxA protein, Dictyostelium discoideum; C413645:dct protein, Dictyostelium discoideum; D024462:Myosin Type II; D020744:rac GTP-Binding Proteins