Patrushev L I, Minkevich I G
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
Biochemistry (Mosc). 2008 Dec;73(13):1519-52. doi: 10.1134/s0006297908130117.
The current state of knowledge concerning the unsolved problem of the huge interspecific eukaryotic genome size variations not correlating with the species phenotypic complexity (C-value enigma also known as C-value paradox) is reviewed. Characteristic features of eukaryotic genome structure and molecular mechanisms that are the basis of genome size changes are examined in connection with the C-value enigma. It is emphasized that endogenous mutagens, including reactive oxygen species, create a constant nuclear environment where any genome evolves. An original quantitative model and general conception are proposed to explain the C-value enigma. In accordance with the theory, the noncoding sequences of the eukaryotic genome provide genes with global and differential protection against chemical mutagens and (in addition to the anti-mutagenesis and DNA repair systems) form a new, third system that protects eukaryotic genetic information. The joint action of these systems controls the spontaneous mutation rate in coding sequences of the eukaryotic genome. It is hypothesized that the genome size is inversely proportional to functional efficiency of the anti-mutagenesis and/or DNA repair systems in a particular biological species. In this connection, a model of eukaryotic genome evolution is proposed.
本文综述了关于真核生物种间巨大基因组大小变异与物种表型复杂性不相关这一未解决问题（C值谜，也称为C值悖论）的当前知识状态。结合C值谜，研究了真核生物基因组结构的特征以及作为基因组大小变化基础的分子机制。强调包括活性氧在内的内源性诱变剂创造了一个任何基因组都在其中进化的恒定核环境。提出了一个原始的定量模型和总体概念来解释C值谜。根据该理论，真核生物基因组的非编码序列为基因提供了针对化学诱变剂的全局和差异保护，并且（除了抗诱变和DNA修复系统之外）形成了一个保护真核生物遗传信息的新的第三系统。这些系统的共同作用控制着真核生物基因组编码序列中的自发突变率。据推测，基因组大小与特定生物物种中抗诱变和/或DNA修复系统的功能效率成反比。就此，提出了一个真核生物基因组进化模型。
