Implications of a poroelastic cytoplasm for the dynamics of animal cell shape

摘要: Two views have dominated recent discussions of the physical basis cell shape change during migration and division animal cells: cytoplasm can be modeled as a viscoelastic continuum, forces that its are generated only by actin polymerization actomyosin contractility in cortex. Here, we question both views: suggest is better described poroelastic, hydrodynamic may generally important for dynamics. In poroelastic view, consists porous, elastic solid (cytoskeleton, organelles, ribosomes) penetrated an interstitial fluid (cytosol) moves through pores response to pressure gradients. If pore size small (30-60nm), has been observed some cells, does not globally equilibrate on time length scales relevant motility. Pressure differences across plasma membrane drive blebbing, potentially other type protrusive these pressures higher one part than another, thus cause local change. Local transients could contractility, or activation osmogenic ion transporters membrane. We propose Na(+)/H(+) antiporters (NHE1) at front migrating cells promotes swelling there help motility, acting combination with polymerization. shrinking equator dividing similarly invagination cytokinesis, contractility. Testing hypotheses easy, water difficult analyte track, will require joint effort cytoskeleton physiology communities.