The generality of transient compartmentalization and its associated error thresholds

TL;DR

This paper investigates how transient compartmentalization can enable prebiotic molecular systems to survive mutations and noise, potentially allowing coexistence beyond traditional error thresholds and shedding light on early life transitions.

Contribution

It provides an analytical framework for understanding the dynamics of transient compartments with mutations, identifying regimes of replication, and extending the concept of error thresholds in prebiotic scenarios.

Findings

Diffusion-limited regime shows high variability in compartment composition.

Replication-limited regime results in synchronous growth and low variability.

Transient compartmentalization can enable coexistence beyond classical error thresholds.

Abstract

Can prelife proceed without cell division? A recently proposed mechanism suggests that transient compartmentalization could have preceded cell division in prebiotic scenarios. Here, we study transient compartmentalization dynamics in the presence of mutations and noise in replication, as both can be detrimental the survival of compartments. Our study comprises situations where compartments contain uncoupled autocatalytic reactions feeding on a common resource, and systems based on RNA molecules copied by replicases, following a recent experimental study. Using the theory of branching processes, we show analytically that two regimes are possible. In the diffusion-limited regime, replication is asynchronous which leads to a large variability in the composition of compartments. In contrast, in a replication-limited regime, the growth is synchronous and thus the compositional variability is low. Typically, simple autocatalysts are in the former regime, while polymeric replicators can access the latter. For deterministic growth dynamics, we introduce mutations that turn functional replicators into parasites. We derive the phase boundary separating coexistence or parasite dominance as a function of relative growth, inoculation size and mutation rate. We show that transient compartmentalization allows coexistence beyond the classical error threshold, above which the parasite dominates. Our findings invite to revisit major prebiotic transitions, notably the transitions towards cooperation, complex polymers and cell division.