Sensitivity of the Mouse Testis to the Mutagenic Action of X-Rays

Abstract

IN making estimates of the damage caused by exposure of human gonads to ionizing radiation, it is essential to take into consideration variations in sensitivity of the germ cells at different stages in their development. In Drosophila, this has been done by mating irradiated males to a succession of females and determining mutation-rates separately for successive broods¹. It was found that spermatids, probably at the stage of transformation into spermatozoa, are the most sensitive stage; mature spermatozoa are one-third or one-fourth as sensitive as spermatids, and spermatocytes are intermediate. Spermatogonia are the least sensitive: a given dose of X-rays produces only one-third to one-half as many mutations in spermatogonia as in spermatozoa.