Selection from a pool of self-assembling lipid replicators

Ignacio Colomer,Arseni Borissov,Stephen P. Fletcher

doi:10.1038/s41467-019-13903-x

Ignacio Colomer, Arseni Borissov + Show 1 more

Open Access

https://doi.org/10.1038/s41467-019-13903-x

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Journal: Nature Communications	Publication Date: Jan 10, 2020
Citations: 39	License type: open-access

Affiliation: University of Oxford

Abstract

Replication and compartmentalization are fundamental to living systems and may have played important roles in life’s origins. Selection in compartmentalized autocatalytic systems might provide a way for evolution to occur and for life to arise from non-living systems. Herein we report selection in a system of self-reproducing lipids where a predominant species can emerge from a pool of competitors. The lipid replicators are metastable and their out-of-equilibrium population can be sustained by feeding the system with starting materials. Phase separation is crucial for selective surfactant formation as well as autocatalytic kinetics; indeed, no selection is observed when all reacting species are dissolved in the same phase. Selectivity is attributed to a kinetically controlled process where the rate of monomer formation determines which replicator building blocks are the fittest. This work reveals how kinetics of a phase-separated autocatalytic reaction may be used to control the population of out-of-equilibrium replicators in time.

Highlights

Replication and compartmentalization are fundamental to living systems and may have played important roles in life’s origins
Living systems are comprised of various functional assemblies and machines which control molecular and greater lengthscale processes
Using the recently reported metastable surfactant replicators 3a or 3c27 as a platform, we decided to explore what differences may be observed between self-replicators kept out-of-equilibrium and self-replication to a thermodynamically stable product[5,6]

Summary

Introduction

Replication and compartmentalization are fundamental to living systems and may have played important roles in life’s origins. 1234567890():,; Living systems are comprised of various functional assemblies and machines which control molecular and greater lengthscale processes These systems operate far-from-equilibrium to control self-organization and synthetic processes including self-replication[1,2,3,4]. The most widely studied class of replicators are based on templated autocatalysis where interactions between self-replicating product and precursors form additional product (Fig. 1a) This molecular replication mechanism is well-known in living systems where RNA and DNA store, transmit and duplicate information. Cellular compartments concentrate and isolate the machinery of life, including informational template molecules like RNA, from the environment[7] Another prebiotic hypothesis involves the “lipid world”, which postulates that autocatalytic amphiphilic boundary structures preceded biopolymers and could have provided suitable microenvironments for the emergence of cellular life[8].

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