Abnormalities in the shape of murine sperm after acute testicular x-irradiation

The fraction of murine epididymal sperm with shape abnormalities ranged from 1.0–15.0% in 14 inbred strains and hybrids studied. The effect of x-rays on this fraction was examined in mice with markedly different natural levels of abnormalities, C₅₇BL (9.4%) and (C₅₇BL×C₃H)F₁ (1.0%). Dosages of 30, 100, and 300 rad produced a significant increase in the number of abnormal forms, especially from 3–8 weeks following irradiation. The fraction of abnormal sperm at 5 weeks following graded doses of radiation from 0–300 rad increased from control values to 30%. The data for the hybrid fitted curve which increased as the $\text{sol3}\text{2}$ power of the dose and which gave a doubling in abnormalities compared with control at rad. Sperm abnormalities may permit a simple quantitative assay for damage to the genetic material of the male germ line.