Patrushev L I
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Biochem Mol Biol Int. 1997 Apr;41(4):851-60.
There has been designed a model to explain the main function of abundant DNA sequences in the eukaryotic genome. The non-coding abundant sequences are supposed to provide two levels of protection of functionally important genome regions against mutations, global and differential. At the first level rather high excess of the nucleotide sequences over the coding ones decreases probability of mutations in coding and other functionally important parts caused by intranuclear mutagens. The second level is achieved by specific chromatin condensation in individual microcompartments of the interphase nucleus and physical accessibility of functionally important sequences to mutagens. These mechanisms might control the optimum mutation rates in some functionally important loci in ontogenesis and might be of help to establish a preferable trend of evolutionary transformations of biological species in phylogenesis.
已经设计了一个模型来解释真核基因组中丰富DNA序列的主要功能。非编码丰富序列被认为可以为功能重要的基因组区域提供两个层面的保护，以防止突变，即全局保护和差异保护。在第一个层面，核苷酸序列相对于编码序列的相当高的过剩量降低了由核内诱变剂引起的编码和其他功能重要部分发生突变的概率。第二个层面是通过间期核的各个微区室中的特定染色质凝聚以及功能重要序列对诱变剂的物理可及性来实现的。这些机制可能控制个体发育中某些功能重要位点的最佳突变率，并且可能有助于在系统发育中确立生物物种进化转变的优选趋势。
