Analysis of Reproductive Capacity and Cytogenetic Effects In Thyroid Gland In Animals After Chronic Exposure To Low Doses of Ionizing Radiation
The study concerns an effect of chronic exposure to low doses of ionizing radiation on fertility and condition of a genome of follicular cells of the thyroid gland for animals from natural populations and in model experiments on Af-line mice. A possibility of transfer of abnormalities detected in exposed parents to their non-irradiated descendants (F1) was studied as well. It is shown that fertility rate of females increases after chronic exposure to small doses (20 and 30 cGy) of γ-irradiation. The same effect is observed for their non-irradiated progeny (30 cGy). Results of molecular and cytogenetic analyses of thyroid follicular epithelium of animals from natural populations and in experimental conditions allow drawing a conclusion on the effect of chronic thyroid exposure to low doses. Study of quality of the irradiated parents progeny (F1) revealed changes at the molecular level (i.e. increased number of double-strand DNA breaks) in the thyroid gland in the offsprings of voles from natural populations inhabiting territories with increased level of radioactivity. Thyroid cytogenetic status of the offspring of mice irradiated in the course of the experiment at a dose of 30 Gy was within normal limits.