Frankenberg D, Goodhead D T, Frankenberg-Schwager M, Harbich R, Bance D A, Wilkinson R E
Int J Radiat Biol Relat Stud Phys Chem Med. 1986 Oct;50(4):727-41. doi: 10.1080/09553008614551121.
Induction of DNA double-strand breaks in diploid wild-type yeast cells, and inactivation of diploid mutant cells (rad54-3) unable to repair DNA double-strand breaks, were studied with aluminium K (1.5 keV) and carbon K (0.278 keV) characteristic X-rays. The induction of DNA double-strand breaks was found to increase linearly with absorbed dose for both characteristic X-rays. Carbon K X-rays were more effective than aluminium K X-rays. Relative to 60Co gamma-rays the r.b.e.-values for the induction of DNA double-strand breaks were found to be 3.8 and 2.2 for carbon K and aluminium K X-rays respectively. The survival curves of the rad54-3 mutant cells were exponential for both ultrasoft X-rays. For inactivation of rad54-3 mutant cells, the r.b.e.-values relative to 60Co gamma-rays were 2.6 and 2.4 for carbon K and aluminium K X-rays, respectively. The DNA double-strand break data obtained with aluminium K and carbon K X-rays are in agreement with the data obtained for gene mutation, chromosome aberrations and inactivation of mammalian cells, suggesting that DNA double-strand breaks are the possible molecular lesions leading to these effects.
利用铝K（1.5 keV）和碳K（0.278 keV）特征X射线，研究了二倍体野生型酵母细胞中DNA双链断裂的诱导情况，以及无法修复DNA双链断裂的二倍体突变细胞（rad54 - 3）的失活情况。发现对于这两种特征X射线，DNA双链断裂的诱导均随吸收剂量呈线性增加。碳K X射线比铝K X射线更有效。相对于60Coγ射线，发现碳K和铝K X射线诱导DNA双链断裂的相对生物效应值分别为3.8和2.2。对于这两种极软X射线，rad54 - 3突变细胞的存活曲线均为指数型。对于rad54 - 3突变细胞的失活，相对于60Coγ射线，碳K和铝K X射线的相对生物效应值分别为2.6和2.4。用铝K和碳K X射线获得的DNA双链断裂数据与哺乳动物细胞基因突变、染色体畸变和失活的数据一致，表明DNA双链断裂可能是导致这些效应的分子损伤。
