Induced reversion of a spontaneous point mutation within the Chinese hamster HPRT gene to the wild-type sequence.
The Chinese hamster hypoxanthine-guanine phosphoribosyltransferase (HPRT)-deficient cell line TG15 produces apparently normal HPRT mRNA by northern analysis and was therefore presumed to contain a point mutation within the coding region. Sequencing cDNA from the TG15 cell line revealed an A to G transition which results in the substitution of the amino acid glycine for aspartic acid at position 135. TG15 cells revert to wild-type HPRT activity upon exposure to monofunctional alkylating agents. A rapid test to assay the site of the TG15 point mutation has been developed, utilizing the polymerase chain reaction and allele-specific oligonucleotide screening. In all revertants studied, the original point mutation has been corrected to the wild-type sequence. The TG15 point mutation lies within a proposed catalytic domain of the HPRT protein in common with other phosphoribosyltransferases.
Institute for Molecular Genetics, Baylor College of Medicine, Houston, TX 77030.
B J
BJ
Rossiter
D M
DM
Muzny
I
I
Hampson
C T
CT
Caskey
M
M
Fox
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics; D005796:Genes; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D015183:Restriction Mapping
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase