Barbieri Marcello
Dipartimento di Morfologia ed Embriologia, Via Fossato di Mortara 64a, 44121 Ferrara, Italy.
Biosystems. 2018 Feb;164:1-10. doi: 10.1016/j.biosystems.2017.10.005. Epub 2017 Oct 6.
Various independent discoveries have shown that many organic codes exist in living systems, and this implies that they came into being during the history of life and contributed to that history. The genetic code appeared in a population of primitive systems that has been referred to as the common ancestor, and it has been proposed that three distinct signal processing codes gave origin to the three primary kingdoms of Archaea, Bacteria and Eukarya. After the genetic code and the signal processing codes, on the other hand, only the ancestors of the eukaryotes continued to explore the coding space and gave origin to splicing codes, histone code, tubulin code, compartment codes and many others. A first theoretical consequence of this historical fact is the idea that the Eukarya became increasingly more complex because they maintained the potential to bring new organic codes into existence. A second theoretical consequence comes from the fact that the evolution of the individual rules of a code can take an extremely long time, but the origin of a new organic code corresponds to the appearance of a complete set of rules and from a geological point of view this amounts to a sudden event. The great discontinuities of the history of life, in other words, can be explained as the result of the appearance of new codes. A third theoretical consequence comes from the fact that the organic codes have been highly conserved in evolution, which shows that they are the great invariants of life, the sole entities that have gone intact through billions of years while everything else has changed. This tells us that the organic codes are fundamental components of life and their study - the new research field of Code Biology - is destined to become an increasingly relevant part of the life sciences.
多项独立研究发现表明,生命系统中存在许多有机编码,这意味着它们在生命历史进程中产生并对生命历史起到了推动作用。遗传密码出现在被称为共同祖先的原始系统群体中,有人提出三种不同的信号处理编码分别产生了古菌、细菌和真核生物这三个主要生物界。另一方面,在遗传密码和信号处理编码出现之后,只有真核生物的祖先继续探索编码空间,并产生了剪接编码、组蛋白编码、微管蛋白编码、区室编码等多种编码。这一历史事实的第一个理论结果是,真核生物变得越来越复杂,因为它们拥有创造新有机编码的潜力。第二个理论结果源于这样一个事实:一种编码的各个规则的进化可能需要极长的时间,但新有机编码的产生意味着一整套规则的出现,从地质学角度来看,这相当于一个突发的事件。换句话说,生命历史中的重大间断可以解释为新编码出现的结果。第三个理论结果源于有机编码在进化过程中高度保守这一事实,这表明它们是生命的重要不变量,是在数十亿年中一切都发生了变化而自身却完好无损的唯一实体。这告诉我们,有机编码是生命的基本组成部分,对它们的研究——编码生物学这一新的研究领域——注定会成为生命科学中越来越重要的一部分。