Theory of fission for two-component lipid vesicles

The coupling between Gaussian curvature and local lipid composition for two-component lipid vesicles can destabilize the narrow neck in a budding transition. Such a coupling reduces the Gaussian rigidity of a membrane and enhances the fission transition if the minor component lipids prefer to stay at regions with large positive Gaussian curvature. On the other hand, it increases the Gaussian rigidity and a fusion transition is enhanced if the minor component lipids are expelled from regions with large positive Gaussian curvature.