Analysis of x-ray-induced chromosomal translocations in human and marmoset spermatogonial stem cells.

Abstract

ONE of the major classes of genetic damage produced by ionising radiations is heritable reciprocal translocation. In a series of earlier publications, Brewen and Preston1–3 demonstrated that each of several mammalian species had its own unique sensitivity to translocation induction in peripheral leukocytes and that human and marmoset leukocytes, although approximately equal in sensitivity, were twice as sensitive as mouse leukocytes. Brewen and Preston4 also reported that in the Chinese hamster and the mouse, the frequency of the translocation type analysed in the peripheral leukocytes was three to four times as high as the frequency of heritable translocations produced in spermatogonial stem cells and recovered in primary spermatocytes. As the mouse is the mammal currently used as the model for estimating man's genetic risk from mutagenic exposure, Brewen and Preston's earlier observations on germ cells should be extended to include a primate and man if possible. Here we present an extension of the interspecific and somatic against germ cell comparisons.