Evolution of views on junk DNA in modern genetics

Tsekhomsky Alexander Vyacheslavovich, Nefedova Larisa Vladimirovna

The purpose of this analytical review is to trace the development of ideas about the quantity, functions, and evolutionary role of non-coding DNA from its discovery in the 1940s to the present. In the course of the study, an analysis of scientific articles, monographs, dissertations and final qualification papers devoted to research in the field of genetics and the role of non-coding DNA elements in particular was carried out. The authors of the papers were leading experts in the field of evolutionary genetics, cytogenetics and genomics. Initially, junk DNA was called that part of the human genome that does not have expression, i.e., does not encode proteins. At the moment, it is believed that non-expressing genes occupy 98% of the human genome, and only the remaining 2% have a biological role in the form of encoding amino acid sequences. Since its discovery, it has been assumed that non-coding DNA has no biological role or evolutionary significance. However, with the development of genetics, more and more studies of “junk” elements of the genome appeared, as a result of which their epigenetic, regulatory, and protective functions became obvious. Many hypotheses are still being debated.

Keywords:gene, junk DNA, evolutionary significance, human genome, gene expression.