Laboratory of Communication Bactérienne et Stratégies Anti-infectieuses UR4312, Université de Rouen, CEDEX, 76821 Mont-Saint-Aignan, France.
Faculty of Medicine, Université Grenoble Alpes, AGEIS EA 7407 Tools for e-Gnosis Medical, 38700 La Tronche, France.
Int J Mol Sci. 2022 Oct 26;23(21):12915. doi: 10.3390/ijms232112915.
It is not entirely clear why, at some stage in its evolution, terrestrial life adopted double-stranded DNA as the hereditary material. To explain this, we propose that small, double-stranded, polynucleotide circlets have special catalytic properties. We then use this proposal as the basis for a 'view from here' that we term the Circlet hypothesis as part of a broader Ring World. To maximize the potential explanatory value of this hypothesis, we speculate boldly about the origins of several of the fundamental characteristics and briefly describe the main methods or treatments applied. The principal prediction of the paper is that the highly constrained, conformational changes will occur preferentially in dsDNA, dsRNA and hybrid RNA-DNA circlets that are below a critical size (e.g., 306 bp) and that these will favor the polymerization of precursors into RNA and DNA. We conclude that the Circlet hypothesis and the Ring World therefore have the attraction of offering the same solution to the fundamental problems probably confronting both the earliest cells and the most recent ones.
目前尚不清楚的是，在进化的某个阶段，为什么陆地生命选择双链 DNA 作为遗传物质。为了解释这一点，我们提出，小的双链多核苷酸环具有特殊的催化特性。然后，我们以此为基础，提出了一个“从这里看”的观点，我们称之为环世界假说，作为更广泛的环世界假说的一部分。为了最大限度地提高这一假说的解释价值，我们大胆推测了几个基本特征的起源，并简要描述了主要的方法或治疗应用。本文的主要预测是，高度约束的构象变化将优先发生在低于临界大小（例如 306bp）的双链 DNA、双链 RNA 和杂交 RNA-DNA 环中，这将有利于前体聚合为 RNA 和 DNA。我们得出结论，因此，环世界假说具有吸引力，它为最早的细胞和最近的细胞可能面临的基本问题提供了相同的解决方案。
