重离子射线照射后抗辐射菌基因组DNA的损伤修复

Genome DNA Damage Repairing Time of the Deinococcus radiodurans after Heavy Ion Beam Irradiation

研究了不同种类的重离子射线及同一射线的不同剂量照射后引起的抗辐射菌(Deinococcus radiodu-rans)R1的DNA二条链的切断损伤修复时间。结果表明,抗辐射菌经重离子射线照射后所引起的DNA二条链的切断损伤经过培养能被修复;切断的DNA二条链的修复时间随着照射剂量的增加而延长;高LET的重离子射线照射所引起的损伤修复比低LET的重离子射线需要更长的时间,损伤修复的时间与射线的LET之间存在一定的依存性。由此认为:抗辐射菌经照射后引起的DNA二条链切断损伤与射线的种类及照射的剂量有关,照射的剂量越大,射线的LET越高,则DNA二条链的切断损伤越多,损伤修复所需要的时间越长。

The damage repairing times of DNA double strand break of Deinococcus radiodurans （DR） R1 after radiation with different kinds of heavy ion beams and different dose of the same beam were studied. The results showed that the DR＇s DNA double strand break damage caused by heavy ion beams could be repaired through culture, and the repairing time extended as the increment of radiation dose. And damage repairing time caused by heavy of high LET （linear energy transfer） ion beam was longer than the one by low LET one, therefore, there is a dependent relation between damage repairing time and the LET of the beam. Therefore it is believed that DR＇s DNA double strand break damage was related to the kinds of beam and the dose of radiation, the bigger the dose, and the higher the LET, the more damage of DNA double strand damage would be, and the repairing time needed would be longer.