Molecular analysis of gamma-ray-induced mutations at the hprt locus in primary human skin fibroblasts by multiplex polymerase chain reaction.
A total of 153 hprt mutants (23 spontaneous, 130 gamma-ray-induced) of primary human skin fibroblasts were isolated and genetic alterations at the locus were studied by multiplex polymerase chain reaction (PCR). The analyses showed that 51% (66/130) of gamma-ray-induced genetic changes were large deletions, whereas the majority of spontaneous mutants (21/23) exhibited point mutations. The spectrum of large genetic alterations appeared to be dependent on dose in gamma-ray-induced (1-4 Gy) mutations; mutants with complete loss of the hprt locus comprised 21 (3/14) or 39% (15/38) of clones isolated after irradiation with 1 or 4 Gy, respectively. The frequency of partial deletions was found to be higher in the mutants isolated from clones irradiated with 2 Gy (38%) than from those irradiated with 4 Gy (8%). Mapping of all intragenic deletion breakpoints exhibited a nonrandom distribution of breakpoints toward the 3' end of the hprt gene.
Park
M S
MS
Life Sciences Division, Los Alamos National Laboratory, New Mexico 87545.
Hanks
T
T
Jaberaboansari
A
A
Chen
D J
DJ
D001483:Base Sequence; D002478:Cells, Cultured; D017931:DNA Primers; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000201:enzymology / Q000528:radiation effects; D005720:Gamma Rays; D017353:Gene Deletion; D005796:Genes / Q000528:radiation effects*; D006801:Humans; D007438:Introns / Q000528:radiation effects*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016133:Polymerase Chain Reaction / Q000379:methods*; D017384:Sequence Deletion; D012867:Skin / Q000201:enzymology* / Q000528:radiation effects
D017931:DNA Primers