Lipid-assisted synthesis of RNA-like polymers from mononucleotides.

A fundamental problem in research on the origin of life is the process by which polymers capable of catalysis and replication were produced on the early Earth. Here we show that RNA-like polymers can be synthesized non-enzymatically from mononucleotides in lipid environments. The RNA-like polymers were initially identified by nanopore analysis, a technique with single molecule sensitivity. To our knowledge, this is the first such application of a nanopore instrument to detect RNA synthesis under simulated prebiotic conditions. The synthesis of the RNA-like polymers was confirmed by standard methods of enzymatic end labeling followed by gel electrophoresis. Chemical activation of the mononucleotides is not required. Instead, synthesis of phosphodiester bonds is driven by the chemical potential of fluctuating anhydrous and hydrated conditions, with heat providing activation energy during dehydration. In the final hydration step, the RNA-like polymer is encapsulated within lipid vesicles. This process provides a laboratory model of an early stage of evolution toward an RNA World.