Mutagenic properties of a unique abasic site in mammalian cells.
The mutagenic properties of a true unique abasic site located opposite a guanine residue were studied. An oligonucleotide containing a chemically-produced abasic site was inserted into a shuttle vector able to replicate both in simian cells and in bacteria. Plasmid DNA was rescued from simian cells and screened in bacteria by differential hybridization with a labelled oligonucleotide probe. Mutations were easily detected and sequenced. Results showed that opposite a guanine the abasic site was error free repaired or replicated by mammalian cells with an efficiency of 99%. Point mutations occurred at a frequency of approximately 1% in control host cells and at more than 3% in UV-pre-irradiated host cells. Adenine, cytosine or thymine were found to have been inserted opposite the abasic site. No preferential insertion for a particular base was observed in contrast to that reported in bacteria.
Gentil
A
A
Laboratory of Molecular Genetics, Institut de Recherches Scientifiques sur le Cancer, Villejuif, France.
Renault
G
G
Madzak
C
C
Margot
A
A
Cabral-Neto
J B
JB
Vasseur
J J
JJ
Rayner
B
B
Imbach
J L
JL
Sarasin
A
A
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002874:Chromosome Mapping; D004247:DNA / Q000737:chemistry*; D005787:Gene Frequency; D000882:Haplorhini; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids
D004247:DNA