The relationship between induced reciprocal translocations and cell killing of rhesus monkey spermatogonial stem cells after combined treatments with follicle-stimulating hormone and X-rays

Abstract

The induction of reciprocal translocations in spermatogonial stem cells of monkeys (rhesus and crabeating), visualized in dividing primary spermatocytes, was studied after combined treatments with folliclestimulating hormone (FSH, 54 IU/kg/week) and X-rays (1 Gy). No clear differences in the frequencies of induced translocations between FSH-pretreated and non-pretreated animals were recorded. Comparison of these translocation data with studies on cell killing in the same monkeys shows that the ratio between the probabilities that radiation-induced basic lesions kill a cell or produce translocations (the p/c ratio) is of the same order of magnitude as that observed for the mouse. Consequently the well documented differences in radiation response between the rhesus monkey and the mouse cannot be explained by differences in the p/c ratio. It is concluded that differences in multiplication-differentiation patterns of surviving stem-cell spermatogonia after irradiation are probably responsible for the observed differences between mice and rhesus monkeys.