Conditioning of the Mouse Fetus Against X-Irradiation Death

Conclusions

Irradiation of the mouse fetus at 15.5 days gestation to only 10 r x-rays will give it a considerably better chance of survival if it is subjected to the LD/50/30 range of exposure when adult. Other fetal ages from 14.5 to 16.5 days show some benefit of 10 r exposure, but higher exposures (25 r to 300 r) to any age fetus will have a deleterious effect in later life if the mouse is exposed to x-rays.