Glickman B W, Rietveld K, Aaron C S
Mutat Res. 1980 Jan;69(1):1-12. doi: 10.1016/0027-5107(80)90171-2.
The spectrum of mutations induced by ionizing radiation (gamma-rays) was determined in the lacI gene of E. coli. Base substitution was the principal type of mutational event following ionizing radiation. Both transitions and transversions were produced, and no strong specificity for a particular base pair was observed. The spectra of spontaneous and of ionizing-radiation-induced base-pair changes differed significantly at several locations within the lacI gene. The location of 3 of these differences corresponded to sites of spontaneous deamination "hot spots" from which we conclude that gamma-rays do not cause extensive deamination. The specific locus rate was calculated as 4.5 X 10(-10) mutations per rad per gene copy per cell, and the nucleotide substitution rate was 2.2 X 10(-12) per rad. The frameshift mutation, trpE997, was not reverted by gamma-rays.
在大肠杆菌的lacI基因中确定了电离辐射（γ射线）诱导的突变谱。碱基替换是电离辐射后主要的突变事件类型。转换和颠换均会产生，且未观察到对特定碱基对有强烈的特异性。自发的和电离辐射诱导的碱基对变化谱在lacI基因内的几个位置有显著差异。其中3个差异的位置对应于自发脱氨基“热点”位点，由此我们得出结论，γ射线不会导致广泛的脱氨基。特定基因座的突变率计算为每拉德每细胞每个基因拷贝4.5×10⁻¹⁰个突变，核苷酸替换率为每拉德2.2×10⁻¹²。移码突变trpE997不会被γ射线回复。
