title: Recovery of V79 cell clones with different phenotypes in aminopterin- or azaserine-containing media used for the selection of HGPRT revertants.
abstract: Three 6-thioguanine (6TG)-resistant mutants were mutagen-treated and selected for clones capable of growing in 2 selective media: HAT medium, containing aminopterin (AP) and HAS medium, containing L-azaserine (AS). Both 6TG-sensitive, wild-type clones and 6TG-resistant mutants were found among colonies growing in HAT medium, while only 6TG-sensitive clones grew in HAS medium. Time for expression was required by 6TG-resistant but not by 6TG-sensitive clones, that were fully expressed immediately after treatment. All HAT-resistant, 6TG-resistant clones which were analyzed proved to be resistant to AP. These data were interpreted as follows: in HAT medium, both HGPRT+ revertants and double mutants (HGPRT-, AP-resistant) were selected, while only HGPRT+ revertants were selected in HAS medium. Not all 6TG-resistant mutants were able to produce both classes of HAT-resistant clones.
mesh_terms: D000630:Aminopterin / Q000494:pharmacology; D000818:Animals; D001377:Azaserine / Q000494:pharmacology; D002478:Cells, Cultured; D006224:Cricetinae; D003470:Culture Media; D004351:Drug Resistance; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D009152:Mutagenicity Tests; D012641:Selection, Genetic; D013866:Thioguanine / Q000494:pharmacology
chemical_list: D003470:Culture Media; D001377:Azaserine; D007041:Hypoxanthine Phosphoribosyltransferase; D013866:Thioguanine; D000630:Aminopterin