Sequence analysis of X-ray-induced mutations occurring in a cDNA of the human hprt gene integrated into mammalian chromosomal DNA.
Sequences of 38 independent X-ray-induced mutations in a cDNA of the human hypoxanthine phosphoribosyltransferase (hprt) gene were analyzed after it was integrated into mammalian chromosomes as part of a shuttle vector. There were 15 base substitutions (39%), 9 frameshifts (24%), 11 deletions (29%), and 3 other mutations (8%) of two kinds. Radiation-induced mutations were found throughout the coding region of the gene. Base substitution mutations occurred more often at A:T sites than at G:C sites, and there were more transversions than transitions. Most of the frameshifts and deletions had short direct repeats or a run of several identical bases at the site of the mutation. A slippage misalignment mechanism, suggested previously, can account for the generation of these classes of mutations. The kinds, distribution, and possible mechanism of X-ray-induced mutations were similar to those of spontaneous mutations.
Kimura
H
H
Department of Experimental Radiology, Shiga University of Medical Science, Japan.
Higuchi
H
H
Iyehara-Ogawa
H
H
Kato
T
T
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002875:Chromosomes; D004247:DNA / Q000235:genetics / Q000528:radiation effects*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011830:Radiation Effects; D011831:Radiation Genetics
D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase