title: Detection of deletion mutations in pSV2gpt-transformed cells.
abstract: We have developed a system to study mutations that affect xanthine-guanine phosphoribosyltransferase gene (gpt) expression in hypoxanthine-guanine phosphoribosyltransferase-deficient CHO cells that have been transformed by the plasmid vector pSV2gpt. One isolated transformant, designated AS52, carries a single copy of the Escherichia coli gpt gene stably integrated into the high-molecular-weight DNA and expresses the bacterial gene for the enzyme xanthine-guanine phosphoribosyltransferase. Mutants deficient in this enzyme can be induced in the AS52 cell line by a variety of mutagens, and spontaneous or induced mutants can be selected for resistance to 6-thioguanine (Tgr). Two Tgr clones derived from the AS52 line were analyzed by Southern blot hybridization and were found to contain deletions involving at least a portion of the gpt gene. Because of the small size and stability of the integrated pSV2gpt plasmid, and the well-defined selection protocol for mutant isolation, the AS52 line offers promise as a system suitable for the study of mutation at the molecular level in CHO cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D002872:Chromosome Deletion; D006224:Cricetinae; D003412:Cricetulus; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D005796:Genes; D005798:Genes, Bacterial; D005822:Genetic Vectors; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency; D009154:Mutation; D010053:Ovary; D010430:Pentosyltransferases / Q000235:genetics*; D010957:Plasmids; D013539:Simian virus 40 / Q000235:genetics*
chemical_list: D010430:Pentosyltransferases; C024827:xanthine phosphoribosyltransferase; D007041:Hypoxanthine Phosphoribosyltransferase