Effect of paternal rat irradiation transmitted to the progeny during prenatal development

The transgenerational transmission of radiation damage was investigated on the basis of quantitative changes of nucleic acids and histones, the integral index of tissue and organ cellularity. Male Wistar rats, whole-body irradiated with the dose of 3 Gy of gamma rays, were mated with non-irradiated females 25 or 80 days after exposure and their progeny were investigated on the 15th (embryos), 17th (embryos), or 19th (embryonic brain) day of prenatal development (E15, E17, and E19Br, respectively). A significant increase in DNA and RNA concentration and content was found on the 15th day and predominantly on the 17th day of gestation in the progeny of males irradiated 80 days before mating. On the contrary, in the progeny of the same males, concentration of histones was decreased in groups E15 and E19Br. Finally, the radiation alterations in the progeny arisen from irradiated spermatogonia (by paternal exposure 80 days before mating) were more profound in nucleic acids than in histones. Our findings suggest an incidence of radiation-induced genome instability manifested as enhanced proliferating activity of cells in response to DNA damage in the progeny of males, mated at later intervals after exposure.