Altruistic DNA. About protective functions of the abundant DNA in the eukaryotic genome and its role in stabilizing genetic information.

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.