先进的生物医学研究与创新

Topological Defect Driven Membrane Fission

Mesarec L1, Iglič A1 and Kralj S2,3*

We demonstrated topological-defect driven membrane fission mechanism using a simple phenomenological model. We modeled membranes as effectively two-dimensional systems possessing in-plane ordering. Membrane configurations were described in terms of tensor orientational order parameter and curvature tensor. For demonstrative purpose we considered only membranes exhibiting spherical topology with axial and inversion symmetry. Using Effective Topological Charge Cancellation mechanism we showed that topological defects tend to assemble in regions exhibiting relatively strong Gaussian curvature. In particular, necklike membrane parts exhibit negative Gaussian curvature, which attract topological defects bearing negative topological charge. In geometries of our interest these defects can be formed via {defect, antidefect} depinning mechanism. The assembled defects, localized near the neck, give rise to relatively strong fluctuations at microscopic level, promoting membrane fission.