The fertility of the males and females with the 11; Y translocation in the NIG-III strain rats is investigated. In the males, only the translocation heterozygous specimens (11/11; Y, X/dot-Y) are fertile, but the other combinations of the sex chromosomes always result in the sterility. In the females, however, the specimens with the 11; Y translocation, eventhough it is included at the heterozygous or the homozygous condition, are always fertile.
The present paper deals with the histological examination of the testis of the NIG-III strain rats with the 11; Y translocation in the heterozygous and the homozygous conditions, and those with the X/X/dot-Y and the X/dot-Y/dot-Y sex chromosomes. The histological feature of the 11; Y translocation heterozygous and fertile males is almost similar to that of the normal male, but in the sterile heterozygous males, homozygous males and the other X/X/dot-Y and the X/dot-Y/dot-Y males, the seminiferous tubules is generally smaller than that of the normal one, and the germ cells are always degenerated and hyalinized. Any spermatogenesis has not been observed in these testis. The mode of the degeneration of the germ cells in the sterile males differs by difference of the type in the translocation.
The effect of Aclacinon (ACR) on the X-ray response of the radio-resistant RC-355 cells is investigated. It has been shown that both pre- and posttreatments are effective in enhancing the radiation-induced cell killing. No difference is observed in the effect of the posttreatments with ACR at the concentrations between 0.1 and 0.2μg/ml, while the effect of the pretreatment is revealed to be the concentration-dependent.