Not just garbage
The causes of diseases should be sought in the "dark matter" of DNA
Sergey Kolenov, Hi-tech+
According to American researchers, many pathogenic mutations are hidden in non-coding parts of the genome. Hence, they affect the regulatory networks of the cell, leading to various disorders and even diseases.
Only a small percentage of our genome is involved in protein synthesis. The functions of the remaining part are poorly understood. Probably, some sections of non-coding DNA are involved in the regulation of genes, while others represent genetic garbage accumulated over millions of years of evolution.
Researchers from Clemson University, whose work is described in the press release of Clemson geneticists' collaborative research sheds light on the 'dark' portion of genome, decided to learn more about the functions of the "dark matter" of the genome. To do this, they conducted a thorough study of the transcriptome of fruit flies - that is, the totality of all RNA molecules present in their cells.
Article by Everett et al. Gene expression networks in the Drosophila Genetic Reference Panel is published in the journal Genome Research – VM.
In the classical version, RNA serves as a transfer link between DNA and protein, but many of its types are used for other purposes.
The analysis revealed 4,500 varieties of RNA that were previously unknown to science. Most of them are not involved in protein synthesis. According to the authors, the main function of these molecules is to control the activity of other genes.
Violations in the work of this regulatory network can cause various diseases. Meanwhile, the search for genetic factors that increase the risk of diseases is usually limited to coding DNA. Researchers believe that potentially dangerous mutations should also be looked for in non-coding regions of the genome.
Among other things, the study showed that some of the uncoding RNAs found regulate genes in heterochromatin, a tightly packed part of DNA that has long been considered "silent." It is possible that these molecules influence the activity of "jumping genes" of transposons capable of moving within the genome and responsible for some genetic disorders.
In the future, the authors intend to use the CRISPR gene editing tool to accurately determine the functions of non-coding DNA fragments. To do this, they will cut them out of the genome and check what has changed in the work of individual cells and the whole organism.
Meanwhile, heredity is far from the only factor determining the risk of developing diseases. According to Canadian researchers, a much bigger role is played by a person's lifestyle.
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