[Ultrastructural changes in the ovaries of chickens following exposure to x-rays]

Changes in the ovaries of chicken embryos (17th day of incubation) and in 2-day-old chickens at different terms (2, 24, 72 h) were studied by light and electron microscopic methods after x-ray irradiation in the doses of 606 and 1200 rad. In oocytes of 17 embryos x-ray irradiation acts as an additional factor, enhancing and increasing the degree of chromatin condensation and producing earlier appearance of pachynema stage. In the ovarian oocytes, at diplonema stage, in 2-day-old chickens after irradiation, condensation of chromosomal substance is observed; in this case, irradiation produces a reverse action to that of normal despiralization. Ultrastructural changes in cellular organelles, in nuclear membrane, in particular, depend on the degree of oocyte differentiation and the irradiation dose applied. Within the terms of investigation, x-ray irradiation does not produce any considerable ultrastructural changes in the oocytes, but its disturbes the contacts between them and follicular cells, which is supposed to be the cause of oocyte destruction.