Hera C, Madzak C, Sarasin A
Laboratory of Molecular Genetics, Institut de Recherches Scientifiques sur le Cancer, Villejuif, France.
Mutat Res. 1996 Dec 2;364(3):235-43. doi: 10.1016/s0921-8777(96)00039-0.
SV40 based shuttle vectors able to be packaged as pseudovirions have been used either as naked DNA or as pseudovirus to analyse the mutation frequency and the UV-induced mutation spectra obtained after transfection or infection of COS7 monkey cells. The frequency of supF spontaneous mutants was similar whatever the state of the vector, indicating that the transfection step is not responsible for the high spontaneous mutation frequency when using shuttle vectors. Nevertheless the UV-induced mutation frequency of the supF gene was higher when transfected DNA was replicated into COS7 cells than when pseudovirus infection was performed. The UV induced mutation spectra was basically similar in both situations but a new hot-spot at nucleotide 110 was obtained after pseudovirus infection. UV-pretreated and control COS7 cells were infected with untreated or UV-damaged pi SVPC7 shuttle virus and the survival and the supF mutation frequency were analysed in the progeny. The survival of UV-damaged pseudovirus replicated in 10 J/m2 UV-pretreated cells was 2-fold higher than in untreated cells. This increase in the survival was accompanied by a slight enhancement in the number of supF mutants.
能够包装成假病毒的基于SV40的穿梭载体已被用作裸DNA或假病毒，以分析转染或感染COS7猴细胞后获得的突变频率和紫外线诱导的突变谱。无论载体状态如何，supF自发突变体的频率相似，这表明在使用穿梭载体时，转染步骤与高自发突变频率无关。然而，当转染的DNA在COS7细胞中复制时，supF基因的紫外线诱导突变频率高于进行假病毒感染时。在两种情况下，紫外线诱导的突变谱基本相似，但在假病毒感染后，在核苷酸110处出现了一个新的热点。用未处理或紫外线损伤的pi SVPC7穿梭病毒感染紫外线预处理和对照的COS7细胞，并分析子代中的存活率和supF突变频率。在10 J/m2紫外线预处理细胞中复制的紫外线损伤假病毒的存活率比未处理细胞高2倍。存活率的这种增加伴随着supF突变体数量的轻微增加。
