Mutation spectrum following transfection of ultraviolet-irradiated single-stranded or double-stranded shuttle vector DNA into monkey cells.
We designed a shuttle vector system that allowed a comparison of the mutation spectrum on the supF target gene after transfection of single-stranded or double-stranded DNA into monkey cells. Single-strand-derived plasmids exhibited a spontaneous mutation frequency tenfold higher than double-strand-derived ones. These spontaneous mutations comprised deletions and point substitutions. This system was applied to the study of ultraviolet-induced mutagenesis. Single-stranded DNA exhibited a lower survival and a higher mutation frequency than double-stranded DNA after identical ultraviolet-irradiation. The use of single-stranded DNA allowed us to confirm and complete the data about the targeting of ultraviolet-induced mutations and the exact nature of the base changes involved. One class of mutations was more frequent after transfection of ultraviolet-irradiated single-stranded DNA than for double-stranded DNA: frameshifts represented 10% of the mutants. Multiple mutations, attributed by some authors to an error-prone excision repair process, have also been observed in the spontaneous and ultraviolet-induced mutation spectra following single-stranded DNA transfection, although it cannot be a direct substrate for excision repair.
Madzak
C
C
Laboratory of Molecular Genetics, Institut de Recherches Scientifiques sur le Cancer, Villejuif, France.
Sarasin
A
A
D000818:Animals; D004247:DNA / Q000096:biosynthesis / Q000528:radiation effects*; D004260:DNA Repair; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000096:biosynthesis / Q000528:radiation effects*; D016368:Frameshift Mutation; D005787:Gene Frequency; D000882:Haplorhini; D010957:Plasmids; D015183:Restriction Mapping; D014162:Transfection; D014466:Ultraviolet Rays
D004277:DNA, Single-Stranded; D004247:DNA