Schwintek Philipp, Eren Emre, Mast Christof Bernhard, Braun Dieter
Systems Biophysics, Physics department, Center for NanoScience, Ludwig-Maximilians-Universität München, Munich, Germany.
Elife. 2025 Jul 9;13:RP100152. doi: 10.7554/eLife.100152.
Nucleic acid replication is a central process at the origin of life. On early Earth, replication is challenged by the dilution of molecular building blocks and the difficulty of separating daughter from parent strands, a necessity for exponential replication. While thermal gradient systems have been shown to address these problems, elevated temperatures lead to degradation. Also, compared to constant temperature environments, such systems are rare. The isothermal system studied here models an abundant geological environment of the prebiotic Earth, in which water is continuously evaporated at the point of contact with the gas flows, inducing up-concentration and circular flow patterns at the gas-water interface through momentum transfer. We show experimentally that this setting drives a 30-fold accumulation of nucleic acids and their periodic separation by a threefold reduction in salt and product concentration. Fluid dynamic simulations agree with observations from tracking fluorescent beads. In this isothermal system, we were able to drive exponential DNA replication with Taq polymerase. The results provide a model for a ubiquitous non-equilibrium system to host early Darwinian molecular evolution at constant temperature.
核酸复制是生命起源的核心过程。在早期地球上，复制面临着分子构件稀释以及将子链与母链分离的困难，而这是指数级复制所必需的。虽然热梯度系统已被证明可以解决这些问题，但高温会导致降解。此外，与恒温环境相比，此类系统较为罕见。本文研究的等温系统模拟了前生物地球丰富的地质环境，在该环境中，水在与气流接触点持续蒸发，通过动量传递在气 - 水界面诱导浓缩和环流模式。我们通过实验表明，这种环境驱动核酸积累30倍，并通过盐和产物浓度降低三倍实现周期性分离。流体动力学模拟与追踪荧光珠的观测结果一致。在这个等温系统中，我们能够用Taq聚合酶驱动DNA指数级复制。这些结果为一个普遍存在的非平衡系统在恒温下承载早期达尔文分子进化提供了一个模型。
