Recycling of Informational Units Leads to Selection of Replicators in a Prebiotic Soup

SummaryPrebiotic chemical reactions would have been greatly aided by a process whereby living materials could have been recycled under conditions of limiting resources. Recombination of RNA fragments is a viable means of recycling but has not been demonstrated. Using systems based on the Azoarcus group I intron ribozyme, computational Monte Carlo studies indicate that a moderate level of recycling activity, spontaneous or catalyzed, leads to the most robust selection scenarios. It is interesting that recycling leads to a threshold effect where a dominant species suddenly jumps to fixation. In conjunction, laboratory studies with the Azoarcus ribozyme corroborate these results, showing that mixtures of scrambled and/or deleteriously mutated molecules can recycle their component fragments to generate fully functional recombinase ribozymes. These studies highlight the importance of recombination and recycling jointly in the advent of living systems.

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (156 K)Download as PowerPoint slideHighlights► Recycling of genetic material is important for the origins of life ► Simulation studies show recycling leads to the selection of genotypes from a pool ► Recycling can lead to the sudden emergence of a high-fitness RNA genotype ► Experimental studies with the Azoarcus ribozyme show fragment recycling