Alteration of Genome Structure Induced by Very Low Dose-Rate Irradiation in Mouse Tissues

To understand the effects of low dose-rate radiation on genome structure in vivo, we examined gene mutation and chromosomal abnormality in mouse tissues. The mutation was studied on transgenes in the spleen and liver and also on the Dlb1 gene in intestinal stem cells. The mice were irradiated for 483 consecutive days at three dose-rates of 0.0323, 0.65, and 12.5 ?Gy/min, which resulted in total doses of 21, 414, and 8,000 mGy, respectively. Statistically significant increases were observed for all indices examined when the total dose was 8,000 mGy, whereas no significant difference was observed with 21 mGy or 414 mGy.