Department of Medical Sciences of the University of Turin, Italy.
MAPS Department at the University of Padova, Italy.
Brief Bioinform. 2021 Mar 22;22(2):2172-2181. doi: 10.1093/bib/bbaa041.
Most living organisms rely on double-stranded DNA (dsDNA) to store their genetic information and perpetuate themselves. This biological information has been considered as the main target of evolution. However, here we show that symmetries and patterns in the dsDNA sequence can emerge from the physical peculiarities of the dsDNA molecule itself and the maximum entropy principle alone, rather than from biological or environmental evolutionary pressure. The randomness justifies the human codon biases and context-dependent mutation patterns in human populations. Thus, the DNA 'exceptional symmetries,' emerged from the randomness, have to be taken into account when looking for the DNA encoded information. Our results suggest that the double helix energy constraints and, more generally, the physical properties of the dsDNA are the hard drivers of the overall DNA sequence architecture, whereas the selective biological processes act as soft drivers, which only under extraordinary circumstances overtake the overall entropy content of the genome.
大多数生物依赖双链 DNA（dsDNA）来存储遗传信息并自我延续。这种生物信息一直被认为是进化的主要目标。然而，在这里我们表明，dsDNA 序列中的对称性和模式可以单独从 dsDNA 分子本身的物理特性和最大熵原理中产生，而不是来自生物或环境进化压力。这种随机性解释了人类密码子偏倚和人类群体中与上下文相关的突变模式。因此，当寻找 DNA 编码信息时，必须考虑从随机性中出现的 DNA“特殊对称性”。我们的研究结果表明，双螺旋能量约束，更普遍地说，dsDNA 的物理特性是整体 DNA 序列结构的硬驱动因素，而选择性生物过程则作为软驱动因素，只有在特殊情况下才能超越基因组的整体熵含量。
