PT  - JOURNAL ARTICLE
AU  - Carlos G. Oliver
AU  - Vladimir Reinharz
AU  - Jérôme Waldispühl
TI  - The necessary emergence of structural complexity in self-replicating RNA populations
AID  - 10.1101/218990
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 218990
4099  - http://biorxiv.org/content/early/2017/11/15/218990.short
4100  - http://biorxiv.org/content/early/2017/11/15/218990.full
AB  - The RNA world hypothesis relies on the ability of ribonucleic acids to replicate and spontaneously acquire complex structures capable of supporting essential biological functions. Multiple sophisticated evolutionary models have been proposed, but they often assume specific conditions. In this work we explore a simple and parsimonious scenario describing the emergence of complex molecular structures at the early stages of life. We show that at specific GC-content regimes, an undirected replication model is sufficient to explain the apparition of multi-branched RNA secondary structures – a structural signature of many essential ribozymes. We ran a large scale computational study to map energetically stable structures on complete mutational networks of 50-nucleotide-long RNA sequences. Our results reveal regions of the sequence landscape enriched with multi-branched structures bearing strong similarities to those observed in databases. A random replication mechanism preserving a 50% GC-content suffices to explain a natural drift of RNA populations toward complex stable structures.