A relationship between membrane properties forms a selectivity mechanism for vesicle self-reproduction

Bojan Božiè, Saša Svetina

Institute of Biophysics, Faculty of Medicine, University of Ljubljana

Two essential properties of terrestrial biotic systems are self-reproduction and the ability to regulate their composition. The identification of non-living systems that possess these properties can therefore contribute not only to our understanding of their functioning but also hint at possible prebiotic processes that led to the emergence of life. Growing lipid vesicles have been previously established as having the capacity to self-reproduce. Here it is demonstrated that vesicle self-reproduction can occur only at selected values of vesicle properties. We treat as an example a simple vesicle with membrane elastic properties defined by a membrane bending modulus and spontaneous curvature, whose volume variation depends on the membrane hydraulic permeability and whose membrane exponentially increases. Vesicle self-reproduction is described as a process in which a growing vesicle first transforms its shape from a sphere into a budded shape of two spheres connected by a narrow neck, and then splits into two spherical daughter vesicles. We show that budded vesicle shapes can be reached only under the certain condition. Thus, in a growing vesicle population containing vesicles of different composition, only the vesicles for which this condition is fulfilled can increase their number in a self-reproducing manner.

Email: bojan.bozic@biofiz.mf.uni-lj.si

Address: Lipièeva 2, Si-1000 Ljubljana, Slovenia