Dipartimento di Agrobiologia ed Agrochimica, Università della Tuscia, Via San Camillo De Lellis, 01100 Viterbo, Italy.
Chem Soc Rev. 2012 Aug 21;41(16):5526-65. doi: 10.1039/c2cs35066a. Epub 2012 Jun 8.
Life is made of the intimate interaction of metabolism and genetics, both built around the chemistry of the most common elements of the Universe (hydrogen, oxygen, nitrogen, and carbon). The transmissible interaction of metabolic and genetic cycles results in the hypercycles of organization and de-organization of chemical information, of living and non-living. The origin-of-life quest has long been split into several attitudes exemplified by the aphorisms "genetics-first" or "metabolism-first". Recently, the opposition between these approaches has been solved by more unitary theoretical and experimental frames taking into account energetic, evolutionary, proto-metabolic and environmental aspects. Nevertheless, a unitary and simple chemical frame is still needed that could afford both the precursors of the synthetic pathways eventually leading to RNA and to the key components of the central metabolic cycles, possibly connected with the synthesis of fatty acids. In order to approach the problem of the origin of life it is therefore reasonable to start from the assumption that both metabolism and genetics had a common origin, shared a common chemical frame, and were embedded under physical-chemical conditions favourable for the onset of both. The singleness of such a prebiotically productive chemical process would partake of Darwinian advantages over more complex fragmentary chemical systems. The prebiotic chemistry of formamide affords in a single and simple physical-chemical frame nucleic bases, acyclonucleosides, nucleotides, biogenic carboxylic acids, sugars, amino sugars, amino acids and condensing agents. Thus, we suggest the possibility that formamide could have jointly provided the main components for the onset of both (pre)genetic and (pre)metabolic processes. As a note of caution, we discuss the fact that these observations only indicate possible solutions at the level of organic substrates, not at the systemic chemical level.
生命由新陈代谢和遗传学的密切相互作用构成，两者都围绕着宇宙最常见元素（氢、氧、氮和碳）的化学性质展开。代谢和遗传周期的可传递相互作用导致化学信息、生命和非生命物质的超循环组织和去组织。生命起源的探索长期以来一直分为几种态度，以“遗传学优先”或“新陈代谢优先”等格言为代表。最近，通过考虑能量、进化、原代谢和环境方面的更统一的理论和实验框架，解决了这些方法之间的对立。然而，仍然需要一个统一而简单的化学框架，既能为最终导致 RNA 的合成途径的前体，又能为中心代谢循环的关键组成部分提供前体，这些循环可能与脂肪酸的合成有关。因此，为了研究生命起源的问题，从以下假设出发是合理的：新陈代谢和遗传学具有共同的起源，共享共同的化学框架，并在有利于两者同时发生的物理化学条件下嵌入。这种具有前生物生产力的化学过程的单一性将在达尔文优势方面超过更复杂的零碎化学系统。甲酰胺的前生物化学在一个单一而简单的物理化学框架中提供了核酸碱基、无环核苷、核苷酸、生物羧酸、糖、氨基糖、氨基酸和缩合剂。因此，我们提出了这样一种可能性，即甲酰胺可能共同为（前）遗传和（前）代谢过程的启动提供了主要成分。需要注意的是，我们讨论了这样一个事实，即这些观察结果仅表明在有机底物水平上可能存在解决方案，而不是在系统化学水平上。
