Radiation-induced life span alteration of Drosophila lines with genotype differences.

The research shows that unirradiated Drosophila lines with defects of DNA repair, antioxidant protection and apoptosis have higher speed of ageing, than wild type line. At the same time, depending on the line genotype, the irradiation results in change of life span. Mechanism of postponed effect of low dozes of ionizing radiation on the life span is elaborated. As cells with weakened protection will accumulate damages and will be exposed to ageing with the greater speed, than steady cells, their radio-induced elimination at early development stages will result in delay of age-dependent changes and will lower speed of ageing. In the subsequent irradiated generations the given somatic answer to stress (hormesis) may be replaced by negative genetic effects on the population level (shorter life span).