Scientists of the Institute of Biology Society named after Max Planck in Germany found that mutations in the genome of plants are non-random in nature and with a smaller probability affect the functions of important genes. As the authors of the study write, the results of which were published in the journal Nature, their discovery questioned by one of the central paradigms in evolutionary biology, according to which mutations occur randly throughout the genome, regardless of their consequences.
was originally believed that genetic variations in important areas of genes in organisms are less likely because such mutations more often cause negative consequences and are excluded by natural selection. The organisms, important genes of which remain intact, and the likelihood of mutations is the same in all areas of the genome. However, new data demonstrate that there are molecular mechanisms underlying mutational “bias”.
Researchers analyzed new mutations in the corrosion line of the Arabidopsis Thaliana plant. This made it possible to determine the frequency of mutations in various fields of the genome before they begin to influence the developing organism. It turned out that in the functionally important areas of the genome genuation occurs less frequently: inside the genes, their frequency is doubled, and in particularly important genes for two thirds.
Such bias is explained by epigenomechanism that do not change the DNA sequence itself, but affect the activity of genes and their possible variability. For example, genes can be enriched with nucleotides G and C, which reduces the likelihood of DNA damage. Some molecules are associated with DNA and increase the stability of genes or the efficiency of their repair. In general, it reduces the emergence of harmful mutations in the key areas of the Arabidopsis genome. Such mechanisms could occur in the process of evolution as an adaptation that increases the survival rate of the view.