[Molecular analysis of spontaneous and arsenite-induced mutations at the gpt locus in Chinese hamster ovary cells].
In this study, we examined the mutagenicity of sodium arsenite at the xathine-guanine phosphoribosyl transferase locus (gpt) in a pSV2 gpt-transformed CHO cell line AS52. The chemical induced a dose-dependent increase of mutant frequency at the locus. Nested PCR analysis revealed that the majority of arsenite-induced AS52 mutants had totally deleted the gpt gene. For the spontaneous, 50 mumol/L arsenite--and 100 mumol/L arsenite--induced mutants in AS52 cells, the percentages of total deletion of the gpt gene were 36.00%, 54.72% and 66.67% respectively. The PCR products of gpt gene from nine 100 mumo/L sodium bisulfite-induced mutants were analyzed with direct DNA sequence technology. The frameshift mutation was identified in two mutants (2/9). No genomic alteration could be found in the structural gene examined in the other 7 mutants, where their molecular alterations probably located in the promoter region.
Meng
Z
Z
Division of Environmental Biological Toxicology, Shanxi University, Taiyuan.
Hsie
A W
AW
D000818:Animals; D018053:Arsenites / Q000633:toxicity*; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D004247:DNA / Q000737:chemistry; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction
D018053:Arsenites; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase; C015001:arsenite