[Mutagenic action of tritium on the germ cells of male mice. I. The induction of dominant lethal mutations by tritium oxide and an assessment of its relative biological effectiveness].

The frequency of dominant lethal mutations (DLM) in the germ cells of male mice exposed to either THO- or gamma-irradiation of 137Cs at the dose of 0.5-3.7 Gr was studied. The distribution of the number of dead embryos in females from the control group as well as that at a dose of irradiation less than 1 Gr, corresponds to the Poisson rule. Spermatids appeared to be more radiosensitive than spermatocytes and spermatozoa. The rate of the effect caused by irradiation of both spermatocytes and spermatids did not depend on the dose rate of gamma-irradiation ranging from 1.10(-3) to 1.7 Gr per min. The linear quadratic formula of aD+bD2 describes the relation of the DLM frequency to the doses of either beta- or gamma-irradiation. The THO RBE increases with the decrease of the dose reaching 2.5 at the D less than 0.1 Gr.