| From a physical point of view, the cytoskeleton can be viewed as an active gel. Various theoretical analysis have shown that such a material can display instabilities, provided that the activity exceeds a critical threshold. Cellular systems are usually confined by lipid membranes. We are interested in the influence of such membranes on the dynamics of the cytoskeleton. As a simple example, we analyse the stability of an active gel inside a membrane tube. To this end, we use a multi-component hydrodynamic description that captures the behaviour of active gels on macroscopic length and time scales. We find that the active stresses in the gel can induce a pearling-like instability of the tube and determine the dependence of the activity threshold on parameters characterising the membrane. |
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