title: Targeting of human eNOS promoter to the Hprt locus of mice leads to tissue-restricted transgene expression.
abstract: Phenotypic heterogeneity of the endothelium arises from cell type-specific differences in gene expression. An understanding of the mechanisms that underlie differential gene expression would provide important insight into the molecular basis of vascular diversity. In standard transgenic assays, multiple copies of heterologous DNA cassettes are randomly integrated into the mouse genome, resulting in significant line-to-line variation in expression. To overcome these limitations, we have targeted a single copy of a transgene that contains 1,600 bp of the human endothelial nitric oxide synthase (eNOS) promoter coupled to the LacZ reporter gene to the X-linked hypoxanthine phosphoribosyltransferase (Hprt) locus of mice by homologous recombination. The transgene was inserted in either of the orientations relative to that of the Hprt gene. In mice derived from multiple embryonic stem (ES) cell clones, the expression pattern was limited to a subset of endothelial cells, cardiomyocytes, and vascular smooth muscle cells. These findings suggest that Hprt locus targeting is a feasible tool for studying endothelial cell-restricted gene regulation.
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Molecular Medicine, Boston 02215, USA.
authors.forename: P V
authors.initials: PV
authors.lastname: Guillot
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.forename: J A
authors.initials: JA
authors.lastname: Kuivenhoven
authors.forename: J
authors.initials: J
authors.lastname: Guan
authors.forename: R D
authors.initials: RD
authors.lastname: Rosenberg
authors.forename: W C
authors.initials: WC
authors.lastname: Aird
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001808:Blood Vessels / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D002999:Clone Cells; D004730:Endothelium, Vascular / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000235:genetics*; D018390:Gene Targeting; D017930:Genes, Reporter / Q000235:genetics; D006321:Heart / Q000196:embryology; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics*; D013234:Stem Cells; D019076:Transgenes / Q000235:genetics; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
chemical_list: C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D007041:Hypoxanthine Phosphoribosyltransferase; D001616:beta-Galactosidase