But recently, this seemingly very logical hypothesis “staggered”. There were studies that do not. The fact is that, starting with a clone of Dolly the sheep, scientists are churning out copies of a variety of animals. And meticulous study of these relatives. Frankly, they managed to find the scientists. For example, we obtained clones from animals of different age, very old and very young. If the theory of the accumulation of “accidents” is true, then their lifespan is pre-set by the original. A copy of the old man, already burdened with accumulated damage a parent should live much less than a copy a young.
But nothing like this is observed, the clones live about the same time, – says one of the authors of the research from the Centre for the study of aging and age-related diseases MIPT Peter Fedichev. – It turns out that the accumulation of random mutations does not give a major contribution to aging. Why? The fact that the accumulation of mutations goes out of sync. In some cell tissue can damage one gene and the other other. But the whole fabric as a whole continues to operate normally.
the Researchers used data polnocennogo sequencing for 50 thousand Britons from the English Biobank and built mathematical models of random genetic damage. Was able to show that despite the fact that the total number of accumulated mutations increases with age, this does not lead to significant increase in risks of chronic diseases and death from all causes. But if “if” plays in aging a decisive role, then maybe there’s some other factor that science has not yet discovered? My version had the famous geneticist Vadim Gladyshev, who works at Harvard University. What is its essence?
Man is not born pure, it already has some harmful mutations. But if all our cells come from one fertilized and share a common genome, the genetic damage work is not piecemeal, as in case of accidental damage, and affect all the cells of the body simultaneously. This is a completely different effect. They can greatly affect life expectancy. But how many of these harmful genes may be with us since childhood?
– the Answer gave a new fundamentally new technology of genome sequencing, which allowed to identify the complete coding for his part, said Fedichev. And it is now possible to see how many in the human genome may birth to live harmful mutations. Our calculations show that, on average, each of us has about 60 heavy damage, the damaged gene is impossible. If we consider that we have about 20 thousand genes, most of them are inherited in two copies, of course, all this is far less scary than it might sound. We can live with it.
On��where this figure of 60 mutations? While science has no answer. Obviously there is some mechanism that limits the number of such harmful mutations. It is important to emphasize that each of us 60 these mutations can be purely individual. Speaking figuratively, as the card will fall. And this alignment will largely determine our disease, and life expectancy.
According to Fedichev, a small effect of random damage on the speed of ageing is good news for the makers of drugs against old age. Otherwise, for anti aging would need to think about the individual diagnosis and correction of genetic damages in almost every human cell. Hard to believe that it is technically possible. In addition, new sequencing technology opens for science prospects for identifying the genetic mechanisms of such complex diseases as schizophrenia or autism, each of which is not caused by the defect of any one of the genes.
the Work is published in prestigious international publishing eLife.
