Dodson L A, Masker W E
Mutat Res. 1986 Sep;162(2):137-44. doi: 10.1016/0027-5107(86)90079-5.
We have examined survival and mutagenesis of bacteriophage T7 after exposure to the alkylating agents methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS). It was found that although both alkylating agents caused increased reversion of specific T7 mutations, EMS caused a higher frequency of reversion than did MMS. Exposure of the host cells to ultraviolet light so as to induce the SOS system resulted in increased survival (Weigle reactivation) of T7 phage damaged with either EMS or MMS. However, after SOS induction of the host we did not detect an accompanying increase in mutation frequency measured as either reversion of specific T7 mutants or by generation of mutations in the T7 gene that codes for phage ligase. Neither mutation frequency nor survival of alkylated phage was affected by the umuD,C mutation in the Escherichia coli host nor by the presence of plasmid pKM101. This may mean that the mode of Weigle reactivation that is detected in T7 is not mutagenic in nature.
我们检测了噬菌体T7在暴露于烷化剂甲磺酸甲酯（MMS）和甲磺酸乙酯（EMS）后的存活率和诱变情况。结果发现，尽管两种烷化剂都导致特定T7突变的回复率增加，但EMS引起的回复频率高于MMS。将宿主细胞暴露于紫外线下以诱导SOS系统，导致被EMS或MMS损伤的T7噬菌体存活率增加（韦格尔复活）。然而，在宿主细胞进行SOS诱导后，我们未检测到以特定T7突变体的回复或通过编码噬菌体连接酶的T7基因中产生突变来衡量的突变频率随之增加。烷基化噬菌体的突变频率和存活率均不受大肠杆菌宿主中的umuD、C突变或质粒pKM101的存在影响。这可能意味着在T7中检测到的韦格尔复活模式本质上不是诱变的。
