These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
3 files

Population-level Membrane Diversity Triggers Growth and Division of Protocells

submitted on 14.11.2020, 20:11 and posted on 16.11.2020, 11:08 by Ö. Duhan Toparlak, Anna Wang, Sheref Mansy

To date, multiple mechanisms have been described for the growth and division of model protocells, all of which exploit the cumulative, unidirectional movement of lipids. The aggregate that is more complex grows at the expense of the smaller or less complex aggregate. Imbalances between surface area and volume during growth can generate filamentous vesicles which are typically divided by shear forces. Here we describe another pathway for growth and division that depends simply on differences in composition of fatty acid membranes. Growth is driven by the entropically-favored mixing of lipids between two populations. Division is the result of growth-induced curvature. Importantly, growth and division are cyclic and bidirectional, meaning that vesicles made from one type of lipid, e.g. short-chain fatty acids, grow and divide when fed with vesicles consisting of another type of lipid, e.g. long-chain fatty acids, and vice versa. After equilibration, additional rounds of growth and division are possible through the addition of compositionally distinct vesicles. Since prebiotic synthesis likely gave rise to mixtures of lipids, the data are consistent with the presence of growing and dividing protocells on the prebiotic Earth.


Simons Foundation (290358FY18 and 290358FY19)

European Union’s Horizon 2020 research and innovation programme under grant agreement No 824060


Email Address of Submitting Author


University of Alberta



ORCID For Submitting Author


Declaration of Conflict of Interest

The authors declare no competing financial interests.