title: Isolation and characterization of mutants at the APRT locus in the L-5178Y TK+/TK- mouse lymphoma cell line.
abstract: 2,6-Diaminopurine(DAP)-resistant mutants have been isolated from mouse lymphoma 5178Y TK+/TK- heterozygotes. In the presence of 50 microM DAP, two colony types were isolated. Small colonies contained 50% wild-type adenine phosphoribosyl transferase (APRT) activity (partial mutants), whereas large colonies have undetectable levels of APRT (aprt- mutants). aprt- mutants could be isolated following mutagenesis with ICR-191 or EMS from the partial mutants. Southern blot analysis of EcoRI digested wild-type DNA using a 3.1 kb mouse aprt genomic probe indicated sequence polymorphism at one or both EcoRI sites flanking the allele. Southern blot analysis of one of the partial mutants and one ICR-induced aprt- mutant (single step) indicated that both strains were hemizygous at the APRT locus. Such stable hemizygous strains would be useful in short-term mutagen tests.
mesh_terms: D015075:2-Aminopurine / Q000031:analogs & derivatives / Q000494:pharmacology; D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics* / Q000276:immunology; D000818:Animals; D002460:Cell Line; D004351:Drug Resistance; D005796:Genes; D006579:Heterozygote; D007118:Immunoassay; D007940:Leukemia L5178 / Q000201:enzymology / Q000235:genetics*; D007942:Leukemia, Experimental / Q000235:genetics*; D051379:Mice; D009153:Mutagens; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010430:Pentosyltransferases / Q000235:genetics*; D013937:Thymidine Kinase / Q000235:genetics
chemical_list: D009153:Mutagens; D015075:2-Aminopurine; C007300:2,6-diaminopurine; D010430:Pentosyltransferases; D000228:Adenine Phosphoribosyltransferase; D013937:Thymidine Kinase