Periodic Reporting for period 2 - EvoTrap (Mechanisms to emerge and replicate the first sequence information of life in geothermal microfluidics of early Earth)
Periodo di rendicontazione: 2020-04-01 al 2021-09-30
How could life emerge? Early Life could only be possible by a complex interplay of biochemical processes driven by a variety of geological and physical non-equilibrium conditions. Answering the question of the origins of this concerted ensemble of mechanisms would yield a unique understanding of the basic principles of life, but requires an imperative of exceedingly close collaboration among scientific disciplines. With the increased focus on this question by a growing number of groups from the geosciences, chemistry, physics, and biology, we are now at an inflection point where disciplinary overlaps are creating close collaborations that will be instrumental in moving the field far forward. Our group is able to integrate prebiotic chemistry into physical boundary conditions and aims to recreate the first steps of life through physico-chemical non-equilibrium experiments. Modern techniques and molecular advances combined will give us the opportunity to look into the first steps of living systems. Central questions to adress are ways that RNA or DNA can replicate its information under settings that are likely availlable on the early Earth.
We could show that:
- Random sequences organized themselves into networks of strongly selected sequences if joining two ends that are bound to a third strand
- The joining of strands is a reaction network that is sensitive to the initial concentration and is amplifying this initial concentration, memorizing the initially successful strands not only by sequence, but also by its concentration.
- tRNA, the molecule that links the genetic code to amino acids was shown to have an unexpected replicative role under thermal oscilations.
- Polymerization Ribozymes, catalytic RNA sequences, bred to replicate other RNA, were shown to replicate exponentially under thermal convection provided by constant heating. Interestingly, the ribozymes protected themselves from the heat by accumulating in the form of rings in colder areas of the convection chamber.
- Heated air-water interfaces are able to drive almost all core reactions of prebiotic life: phosphorylation, crystallization of chiral species, accumulation of longer RNA or DNA, encapsulation of RNA/DNA into lipid vesicles, wet-dry cycling and salt cycling and the accumulation of ions and RNA necessary for ribozyme activity.
- Random sequences organized themselves into networks of strongly selected sequences if joining two ends that are bound to a third strand
- The joining of strands is a reaction network that is sensitive to the initial concentration and is amplifying this initial concentration, memorizing the initially successful strands not only by sequence, but also by its concentration.
- tRNA, the molecule that links the genetic code to amino acids was shown to have an unexpected replicative role under thermal oscilations.
- Polymerization Ribozymes, catalytic RNA sequences, bred to replicate other RNA, were shown to replicate exponentially under thermal convection provided by constant heating. Interestingly, the ribozymes protected themselves from the heat by accumulating in the form of rings in colder areas of the convection chamber.
- Heated air-water interfaces are able to drive almost all core reactions of prebiotic life: phosphorylation, crystallization of chiral species, accumulation of longer RNA or DNA, encapsulation of RNA/DNA into lipid vesicles, wet-dry cycling and salt cycling and the accumulation of ions and RNA necessary for ribozyme activity.
We expect to add polymerization to the list of core reactions at heated air-water interfaces. This opens many avenues to start molecular evolution only from two nucleotide molecules. They will be analyzed by mass spectrometry and fingerprints of sequences will be monitored to show and study their evolution under a number of physical non-equilibrium conditions. We hope to also show protein-driven replication in gas-water chambers to the point that strands are separated by combined acid and low salt conditions driven by evaporation and recondensation of water, a setting that is on the microscale similar to how the water cycle acts in the Earth atmosphere.