title: A human-mouse somatic hybrid line selected for human deoxycytidine deaminase.
abstract: A new selective medium has been developed for cells containing the enzyme deoxycytidine deaminase. This medium contains hypoxanthine, aminopterin, and 5-methyldeoxycytidine (HAM medium). To survive in the presence of the aminopterin, the cells must utilize deoxycytidine deaminase to convert the 5-methyldeoxycytidine to thymidine. The cells must also have thymidine kinase and hypoxanthine phosphoribosyltransferase. A mouse cell line deficient in deoxycytidine deaminase has been isolated from a deoxycytidine kinase-deficient line, using 5-bromodeoxycytidine as the selective agent. A hybrid line between this double mutant and a human diploid fibroblast was isolated in HAM medium. The hybrid line contains the chromosomes expected of a human-mouse hybrid. The deoxycytidine deaminase isozyme patterns on cellogel show that the human-mouse hybrid cell line produces an enzyme with an electrophoretic mobility intermediate between that of the human and that of the mouse.
mesh_terms: D000630:Aminopterin; D000818:Animals; D001972:Bromodeoxycytidine / Q000494:pharmacology; D002874:Chromosome Mapping; D002875:Chromosomes; D003470:Culture Media; D003561:Cytarabine / Q000494:pharmacology; D003841:Deoxycytidine / Q000031:analogs & derivatives; D005347:Fibroblasts / Q000648:ultrastructure; D006801:Humans; D006822:Hybrid Cells / Q000201:enzymology*; D007042:Hypoxanthines; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000032:analysis; D051379:Mice; D009154:Mutation; D009700:Nucleoside Deaminases / Q000032:analysis*
chemical_list: D003470:Culture Media; D007042:Hypoxanthines; D007527:Isoenzymes; D003561:Cytarabine; D003841:Deoxycytidine; D001972:Bromodeoxycytidine; D009700:Nucleoside Deaminases; D000630:Aminopterin