title: Comparison of phenotypic expression with genotypic transformation by using cloned, selectable markers.
abstract: The frequency of phenotypic expression of the herpes simplex virus type 1 tk and Escherichia coli gpt genes was compared with the frequency of genotypic transformation after calcium phosphate-mediated DNA transfection of a number of tk- and hprt- cell lines. In three of the five lines tested, the frequency of phenotypic expression was at most 10-fold higher than that of genotypic transformation as indicated by frequency of HAT resistance. The remaining two lines showed phenotypic responses which were 50- to 100-fold greater than the genotypic responses. The data indicate that the efficiency of DNA-mediated transformation with some cell lines can be limited by events after the uptake and expression of transfected DNA.
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004274:DNA, Recombinant; D005786:Gene Expression Regulation; D005819:Genetic Markers; D005838:Genotype; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D051379:Mice; D010641:Phenotype; D012641:Selection, Genetic; D018139:Simplexvirus / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics; D014162:Transfection; D014170:Transformation, Genetic
chemical_list: D004274:DNA, Recombinant; D005819:Genetic Markers; D007041:Hypoxanthine Phosphoribosyltransferase; D013937:Thymidine Kinase