American scientists have found that naked mole rats, unlike humans and other animals, have almost no increased risk of death throughout their lives. This suggests that the aging mechanism is a genetic or epigenetic program, and not an accumulation of random defects in DNA. The study is reported by Science magazine.
Theories that explain the causes of aging are divided into two types. The former suppose that in living things there are mechanisms that determine the lifespan. Others believe that aging is a consequence of mutations accumulated over time, failures and deterioration of "repair" systems in cells. In this case, the risk of death should increase with age.
According to Gompertz's law, every eight years of life after 30 years, the probability of death doubles. Biologists analyzed changes in mortality rates in several thousand naked mole rats of different ages. It turned out that they do not obey Gompertz's law. After reaching puberty at six months, the daily risk of death remained at 0.01 percent for almost the entire life (15-30 years). Females of the animal remained fertile even at a later age.
Scientists believe that naked mole rat cells have high activity of DNA repair systems, as well as chaperones, proteins that maintain the correct structure of other proteins. This prevents the animals from accumulating genetic defects.
Researchers believe that rodents do age, but they do this atypically. Perhaps after 20-30 years of age, mole rats can no longer maintain the functions of the body's repair, which as a result wears out quickly.