The Effect of Ancestral Irradiation Exposure on Radioresistance in Their Descendants

Abstract
The com-parative resistance of three lines of mice with different histories of ancestral X-ray exposure to protracted gamma-irradiation, fractionated X-irradiation, and acute LD50(30) X-irradiation was studied. Mice from fifteen generations of X-irradiated sires and from ten generations of X-irradiated sires, followed by six generations with no irradiation, were comparatively less resistant to both protracted gamma-ray and fractionated X-ray exposure than were control line mice. There was no comparative LD50(30) difference among the three groups.