title: Unstable integration of transfected DNAs into embryonal carcinoma cells.
abstract: Plasmid DNA can be efficiently transfected into embryonal carcinoma cells but it is difficult to isolate clones of cells stably expressing genes present on the transfected plasmids. Even in clonal populations derived from transfected cells, the introduced genes are expressed in some but not all cells. Cotransfection with a region of the Pgk-1 gene results in more efficient, stable cotransformation due to increased numbers of copies of the transfected plasmids integrated into the genomic DNA. The PgK-1 genomic sequences did not allow the plasmid DNA to replicate autonomously but seemed to enhance the ligation of transfected plasmids before their integration into the host genome. Our results suggest a model in which the plasmid DNAs are able to integrate and subsequently excise from the host genome by recombination events enhanced by transcription through the tandemly repeated sequences of the transfected plasmids.
authors.affiliation: University of Ottawa, Department of Medicine, Ontario, Canada.
authors.forename: M W
authors.initials: MW
authors.lastname: McBurney
authors.forename: S
authors.initials: S
authors.lastname: Fournier
authors.forename: P K
authors.initials: PK
authors.lastname: Schmidt-Kastner
authors.forename: K
authors.initials: K
authors.lastname: Jardine
authors.forename: J
authors.initials: J
authors.lastname: Craig
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D018236:Carcinoma, Embryonal; D016521:Electrophoresis, Gel, Pulsed-Field; D017930:Genes, Reporter; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008957:Models, Genetic; D010735:Phosphoglycerate Kinase / Q000235:genetics*; D011691:Puromycin / Q000494:pharmacology; D014162:Transfection; D014170:Transformation, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D011691:Puromycin; D010735:Phosphoglycerate Kinase