Some comparisons between induced and spontaneous mutation rates in mouse sperm and spermatogonia.

The induction of histocompatibility gene mutations in BALB/cKh mouse sperm was determined following doses of 0, 350, or 350 + 300 rad (24 h apart) of 250 kV X-rays. The mutation rate is significantly lower than predicted on the basis of the seven-locus test and is not significantly different from the very low rate of H-loci in BALB/cKh spermatogonia. Furthermore, selection and repair are important in determining mutation rates per viable progeny of H-loci during both spermatogenesis and gestation.