Kawamura Kunio
Department of Human Environmental Studies, Hiroshima Shudo University, 1-1-1, Ozuka-higashi, Asaminami-ku, Hiroshima 731-3195, Japan.
Life (Basel). 2016 Aug 2;6(3):29. doi: 10.3390/life6030029.
RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes.
RNA在原始地球上首个类生命系统的出现过程中发挥了核心作用，因为RNA分子既包含遗传信息又具备催化活性。然而，RNA世界假说存在若干缺陷。在此，我简要探讨RNA世界假说的可行性，以推断形成类生命系统所必需的RNA功能。同时，我对生物系统的特征进行了概念分析，作为一种有用的方法来推断与生命定义相关的现实类生命系统。例如，一个基于RNA的类生命系统应该通过形成类似细胞的区室等方式，具备足够的稳定性以抵抗环境扰动。在此，总结了一种概念观点，以提供一个与原始地球环境和RNA分子能力相兼容的现实类生命系统。根据实证和概念分析，我提出首个类生命系统可能仅由两个基因起始的假说。
