The DNA replication process can be a source of genetic instability. As shown in this study, researchers from the Department of Genetics at the University of Seville, a defective deposition of histones leads to recombinagenic structure formation during replication of DNA generated by such genomic instability.

The close relationship between replication and assembly of nucleosomes allows authors to compare their working hypothesis, analyzing the effect exerted by the partial removal of histone H4 on genetic instability mediated by homologous recombination. To do this, they constructed a strain of Saccharomyces cerevisiae in regulating the expression of histone H4. Partial removal of this histone, and therefore a defective assembly of nucleosomes, producing subtle changes in plasmid super helical density model for the study and the sensitivity of chromatin to nuclease micrococal, indicators of market failures.

Under these conditions, homologous recombination was much higher than the wild hiperrecombinacion not associated, according to the authors, with alterations in the repair or transcription but with an accumulation of lesions in DNA recombinant origin. The authors noted that the partial removal of histone H4 caused alterations in the corresponding phases of the cell cycle, from which derives his role in the formation of structures recombinagenic source of instability.