Prebiotic foam environments to oligomerize and accumulate RNA

Emre Tekin, Annalena Salditt, Philipp Schwintek, SreeWunnava, Juliette Langlais, James Saenz, Dora Tang, PetraProf. Schwille, Christof Mast, and Dieter Braun

ChemBioChem https://doi.org/10.1002/cbic.202200423

Abstract

When water interacts with porous rocks, its wetting and surface tension properties create air bubbles in large number. To probe their relevance as a setting for the emergence of life, we we microfluidically created foamsthat were stabilized with lipids. Apersistent non-equilibrium setting was provided by a thermal gradient. The foam’s large surface area triggers capillary flows and wet-dry reactions that accumulate, aggregate and oligomer-ize RNA, offering a compelling habitat for RNA-based early life as it offers both wet and dry conditions in direct neighborhood. Lipids werescreened to stabilize the foams. The prebiotically more prob-able myristic acid stabilized foams over many hours. The capillary flow created by the evaporation at the water-air interface provided an attractive force for molecule localization and selectionfor mol-ecule size. For example, self-binding oligonucleotide sequences accumulated and formed micrometer-sized aggregates which were shuttled between gas bubbles. The wet-dry cycles at the foam bubble interfaces triggered a non-enzymatic RNA oligomer-ization from 2',3'-cyclic CMP and GMPwhich despite the small dry reaction volume was superior to the corresponding dry reac-tion. The foundcharacterists make heated foams an interestinglocalized setting for early molecular evolution.