Gene recombination of genes
The gene responsible for the genetic diversity of people has been isolatedFernando de la Cuadro, Compulenta
Sir Alec Jeffries, professor of genetics at the University of Leicester (UK), already has services to humanity: it is enough to recall the DNA fingerprinting invented by him, which allows, for example, to establish paternity and expose criminals.
Since 1984, when Mr. Jeffries made this discovery, he has been interested in, in his own words, "very strange fragments of DNA" – so-called mini-satellites that change at a much faster rate than the rest of the DNA.
For the past ten years, the scientist and his team have been engaged in recombination of genes – a phenomenon that occurs in every new generation and which Jeffries himself popularizes with shuffling a deck of cards. Recombination of genes makes possible the genetic diversity of people (manifested, among other things, as the dissimilarity of individuals from each other). So, Jeffries and colleagues were able to localize the DNA regions where most of the recombinations occur, and isolate the PRDM9 gene, which is responsible for creating the protein that provokes the phenomenon under study.
It turned out that people with different types of PRDM9 demonstrate significantly different gene recombination patterns. Differences are manifested not only in specific DNA regions, but also at the chromosomal level (which in some cases can cause genetic diseases in offspring). In fact, new genetic risk factors have been discovered; further research in this direction can help prevent many genetic diseases.
Sir Alec sees some irony in the fact that his mini-satellite is responsible for the variability of PRDM9, which thus has a key influence on the diversity of the entire human DNA. "The circle has closed: I started with mini-satellites and came to mini-satellites," says the scientist.
Researchers from Leicester have simultaneously solved one of the long-standing mysteries of gene recombination. The areas of DNA where it occurs most actively have "suicidal tendencies" – they are destroyed very quickly. But the mini-satellite with PRDM9 evolves even faster and constantly provokes the creation of new sites for recombination. "This is an absolutely insane mechanism, but typical of the strange solutions that evolution develops," explains the professor.
The results of the study are published in the journal Nature Genetics (Ingrid L Berg et al., PRDM9 variation strongly influences recombination hot-spot activity and meiotic instability in humans).
Prepared by ScienceDaily: Role of Key Genetic Catalyst for Human Diversity DiscoveredPortal "Eternal youth" http://vechnayamolodost.ru