Molecular bases of the effect of low doses of radiation

Abstract

By definition, low doses are minimum doses of a damaging agent, in particular radiation, causing a recorded biological effect. The problem of exposure to low doses of radiation is being discussed in scientific literature for decades, but there is still no generally accepted conclusion concerning the existence of some features of the effect of low doses in contrast to that of acute exposure. This is due to the fact as follows: if being fixed, these effects have a weak expression and can be easily criticized. The second important aspect of this problem is that biological effects are mainly described phenomenologically in literature, without deciphering their molecular causes. In recent years, a number of articles appeared in which the authors, when studying exposure to low doses of DNA-tropic agents, show that postreplication repair (in particular, its error-free branch) plays a key role in these effects. In the laboratory of eukaryotic genetics of Petersburg Nuclear Physics Institute named by B. P. Konstantinov, it was possible to isolate unique yeast mutants with a disrupted branch of error-free postreplication repair. A study of the processes of eliminating DNA damage with minimal deviations of their number from a spontaneous level made it possible to explain at the molecular level the differences in cell response to low doses from acute exposure.