title: Selection of morphologically normal cell lines from polyoma-transformed BHK21/13 hamster fibroblasts.
abstract: A selective method was devised for the isolation of "revertants" from polyoma-transformed sublines derived from BHK21/13 Syrian hamster fibroblasts. A hybrid, polyploid subline was obtained by growing together, in mixed culture in the presence of aminopterin, two variant BHK21/13 sublines lacking either inosinic acid pyrophosphorylase or thymidine kinase. Whereas these variant sublines were resistant to 6-thioguanine or to 5-bromodeoxyuridine, the hybrid had regained sensitivity to both analogues. By plating a polyoma-transformed subline derived from this hybrid in the presence of 6-thioguanine, resistant clones were obtained with a frequency of about 10(-4). All of these surviving clones had a reduced chromosome complement and some of them had regained a normal phenotype.
mesh_terms: D000630:Aminopterin / Q000494:pharmacology; D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002869:Chromosome Aberrations; D002875:Chromosomes; D006224:Cricetinae; D046508:Culture Techniques; D005347:Fibroblasts; D005998:Glycine / Q000494:pharmacology; D006824:Hybridization, Genetic; D007042:Hypoxanthines / Q000494:pharmacology; D007621:Karyotyping; D007668:Kidney; D011120:Polyomavirus; D013866:Thioguanine / Q000494:pharmacology; D013936:Thymidine / Q000494:pharmacology
chemical_list: D007042:Hypoxanthines; D013866:Thioguanine; D001973:Bromodeoxyuridine; D000630:Aminopterin; D005998:Glycine; D013936:Thymidine