Analysis of mutations in the human HPRT gene induced by accelerated heavy-ion irradiation.
Multiplex PCR analysis of HPRT(-) mutations in human embryo (HE) cells induced by 230 keV/microns carbon-ion irradiation showed no large deletion around the exon regions of the locus gene in contrast to the irradiations at different LETs. To identify these mutations, the sequence alterations in a cDNA of hprt gene were determined for 18 mutant clones in this study. Missing of exon 6 was the most frequent mutational event (10 clones), and missing of both exons 6 and 8 was next most frequent event (6 clones), then base substitutions (2 clones). These characteristics were not seen in a similar analysis of spontaneous mutations, which showed base substitution (5 clones), frameshift (2 clones), missing of both exons 2 and 3 (2 clones), and a single unidentified clone. Direct sequencing and restriction enzyme digestion of the genomic DNA of the mutants which showed missing of exons 6 and 8 in the cDNA, supports the possibility that they were induced by aberrant mRNA splicing.
Kagawa
Y
Y
Institute of Physical and Chemical Research, Saitama, Japan.
Yatagai
F
F
Suzuki
M
M
Kase
Y
Y
Kobayashi
A
A
Hirano
M
M
Kato
T
T
Watanabe
M
M
Hanaoka
F
F
D001483:Base Sequence; D002244:Carbon; D004252:DNA Mutational Analysis; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000528:radiation effects*; D010315:Particle Accelerators; D016133:Polymerase Chain Reaction
D002244:Carbon; D007041:Hypoxanthine Phosphoribosyltransferase