title: Targeting of nonexpressed genes in embryonic stem cells via homologous recombination.
abstract: Gene targeting via homologous recombination-mediated disruption in murine embryonic stem (ES) cells has been described for a number of different genes expressed in these cells; it has not been reported for any nonexpressed genes. Pluripotent stem cell lines were isolated with homologously recombined insertions at three different loci: c-fos, which is expressed at a low level in ES cells, and two genes, adipsin and adipocyte P2 (aP2), which are transcribed specifically in adipose cells and are not expressed at detectable levels in ES cells. The frequencies at which homologous recombination events occurred did not correlate with levels of expression of the targeted genes, but did occur at rates comparable to those previously reported for genes that are actively expressed in ES cells. Injection of successfully targeted cells into mouse blastocysts resulted in the formation of chimeric mice. These studies demonstrate the feasibility of altering genes in ES cells that are expressed in a tissue-specific manner in the mouse, in order to study their function at later developmental stages.
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA.
authors.forename: R S
authors.initials: RS
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Sheng
authors.forename: M E
authors.initials: ME
authors.lastname: Greenberg
authors.forename: R D
authors.initials: RD
authors.lastname: Kolodner
authors.forename: V E
authors.initials: VE
authors.lastname: Papaioannou
authors.forename: B M
authors.initials: BM
authors.lastname: Spiegelman
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D002678:Chimera; D011416:Complement Factor D; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D051379:Mice; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics*; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011995:Recombination, Genetic; D012697:Serine Endopeptidases / Q000235:genetics*; D013234:Stem Cells / Q000378:metabolism*; D014162:Transfection
chemical_list: D002352:Carrier Proteins; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D012697:Serine Endopeptidases; D011416:Complement Factor D; C493491:complement factor D, mouse