beecee Posted October 20, 2021 Posted October 20, 2021 https://phys.org/news/2021-10-team-approach-unveil-life-evaporation.html Team discovers a new approach to unveil the Origin of Life: Evaporation: The image shows the evaporation-induced phase separation process inside an all-aqueous sessile droplet (Scale bar: 500 microns). The droplet is initially single-phase with PEG (Polyethylene glycol) and dextran dissolved. Upon evaporation, the concentration of PEG and dextran increases and incompatibility arises, forming tiny dextran-rich droplets (green fluorescently labelled) dispersed in the continuous PEG-rich phase. These tiny dextran-rich droplets move towards the center of the sessile droplet with the inward Marangoni flow. Compartmentalization and localization of biopolymers like nucleic acids (red fluorescently labelled) inside these dextran-rich droplets are achieved, with great potential in serving as all-aqueous reactors for a wide range of biochemical reactions. Credit: The University of Hong Kong What is the origin of life? It is a question that has consumed the work and time of scientists for centuries. Recently a group of researchers from the University of Hong Kong (HKU) has shed light on the possible ways forward to examine how living things are formed. more at link.... the paper: https://www.nature.com/articles/s41467-021-23410-7 Non-associative phase separation in an evaporating droplet as a model for prebiotic compartmentalization: Abstract: The synthetic pathways of life’s building blocks are envisaged to be through a series of complex prebiotic reactions and processes. However, the strategy to compartmentalize and concentrate biopolymers under prebiotic conditions remains elusive. Liquid-liquid phase separation is a mechanism by which membraneless organelles form inside cells, and has been hypothesized as a potential mechanism for prebiotic compartmentalization. Associative phase separation of oppositely charged species has been shown to partition RNA, but the strongly negative charge exhibited by RNA suggests that RNA-polycation interactions could inhibit RNA folding and its functioning inside the coacervates. Here, we present a prebiotically plausible pathway for non-associative phase separation within an evaporating all-aqueous sessile droplet. We quantitatively investigate the kinetic pathway of phase separation triggered by the non-uniform evaporation rate, together with the Marangoni flow-driven hydrodynamics inside the sessile droplet. With the ability to undergo liquid-liquid phase separation, the drying droplets provide a robust mechanism for formation of prebiotic membraneless compartments, as demonstrated by localization and storage of nucleic acids, in vitro transcription, as well as a three-fold enhancement of ribozyme activity. The compartmentalization mechanism illustrated in this model system is feasible on wet organophilic silica-rich surfaces during early molecular evolution.
jimmydasaint Posted October 23, 2021 Posted October 23, 2021 Good find beecee. This article seems to be crossing the abiogenesis -biogenesis divide. Just a couple of questions. 1. Which organelles form this way in a cell which is approximately 90 percent water? 2. Presumably these experiments use pure reactants. Have they extended a similar model towards a "noisy" cell environment? I don't have time to read the whole article but presume you have mate. Cheers
Recommended Posts