Alarcón-Hernández E, Cabrera-Juárez E
Laboratorio de Genética molecular, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, I.P.N., México, D.F.
Rev Latinoam Microbiol. 1992 Jan-Mar;34(1):61-6.
Transforming DNA containing the streptomycin resistance marker, was irradiated for 8 h with broad near ultraviolet light (325-400 nm) at pH 4.8, and the inactivation kinetics determined. After selection of streptomycin resistant transformants, they were grown until a turbidity of 150-200 Klett units. In these cultures we looked for new markers coming from the irradiated transforming DNA. We looked and found the novobiocin resistance marker and one that conveys to protoporphyrin IX utilization, measured as an increase in the mutation frequency of these markers in the streptomycin resistant population. In other experiments, we found a decline in spontaneous mutation frequency for the same markers in the cells transformed with irradiated DNA. This last finding rises the possibility of alterations on the mutator genes as a result of near ultraviolet irradiation.
含有链霉素抗性标记的转化DNA在pH 4.8条件下用宽谱近紫外光（325 - 400纳米）照射8小时，并测定其失活动力学。在选择出链霉素抗性转化体后，将它们培养至浊度达到150 - 200 Klett单位。在这些培养物中，我们寻找来自经照射的转化DNA的新标记。我们进行了查找并发现了新生霉素抗性标记以及一个赋予原卟啉IX利用能力的标记，这通过链霉素抗性群体中这些标记的突变频率增加来衡量。在其他实验中，我们发现用经照射的DNA转化的细胞中，相同标记的自发突变频率有所下降。这一最新发现增加了近紫外照射导致诱变基因发生改变的可能性。
