The analysis of DNA repair genes expression in the blood of total body irradiated mice

In this paper the expression changes of genes involved in DNA repair induced by radiation at different doses and post-irradiation time points has been investigated and the possibility of combining some genes as biomarkers for bio-dosimeter has been evaluated. The whole body of experimental mice was irradiated with 0, 2, 4, 6 and 8 Gy 137Cs γ-rays at 0.80 Gy/min and 1.60 Gy/min, respectively. Peripheral blood was collected at immediate, 4, 8, 12, 24 and 48 h after irradiation and RNA was extracted by AxyPrep Kit. The mRNA transcriptional expression levels of ATM, CDKN1A, DDB2 and GADD45A were detected by real-time quantitative polymerase chain reaction (RT-PCR). Expression changes of mRNA were compared with that of unirradiated control group at the dose rate of 0.8 Gy/min. A series of dose-and time-response of the changes were figured out. A heavy change in magnitude of genes transcription induced by irradiation at higher exposure dose rate could be found. The information from gene expression analysis as a greatly potential biomarkers may be used to indicate exposure doses at different post irradiation time points in a certain dose range. (authors)