title: DNA-mediated gene transfer is more efficient during S-phase of the cell cycle.
abstract: We transformed synchronized mouse L-thymidine kinase deficient cells with a cloned thymidine kinase gene and carrier DNA at different times in the cell cycle. The frequency of resistant colonies was determined after growth in hypoxanthine-aminopterin-thymidine medium for two weeks (late expression) and the frequency of thymidine kinase positive cells was determined 72 hours after transformation (early expression) by incorporation of 3H-thymidine and autoradiography. The frequency of late expression was several-fold higher when cells were exposed to DNA during S-phase, whereas the frequency of early expression did not depend on the phase of the cell cycle.
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D002472:Cell Transformation, Viral; D003001:Cloning, Molecular; D003703:Demecolcine / Q000494:pharmacology; D005796:Genes; D007399:Interphase; D007700:Kinetics; D007739:L Cells / Q000201:enzymology; D051379:Mice; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics*
chemical_list: D013937:Thymidine Kinase; D003703:Demecolcine