title: Insertion of enhanced green fluorescent protein into the lysozyme gene creates mice with green fluorescent granulocytes and macrophages.
abstract: Pluripotent hematopoietic stem cells have been studied extensively, but the events that occur during their differentiation remain largely uncharted. To develop a system that allows the differentiation of cultured multipotent progenitors by time-lapse fluorescence microscopy, myelomonocytic cells were labeled with green fluorescent protein (GFP) in vivo. This was achieved by knocking the enhanced GFP (EGFP) gene into the murine lysozyme M (lys) locus and using a targeting vector, which contains a neomycin resistant (neo) gene flanked by LoxP sites and "splinked" ends, to increase the frequency of homologous recombination. Analysis of the blood and bone marrow of the lys-EGFP mice revealed that most myelomonocytic cells, especially mature neutrophil granulocytes, were fluorescence-positive, while cells from other lineages were not. Removal of the neo gene through breeding of the mice with the Cre-deleter strain led to an increased fluorescence intensity. Mice with an inactivation of both copies of the lys gene developed normally and were fertile. (Blood. 2000;96:719-726)
authors.affiliation: Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: N
authors.initials: N
authors.lastname: Faust
authors.forename: F
authors.initials: F
authors.lastname: Varas
authors.forename: L M
authors.initials: LM
authors.lastname: Kelly
authors.forename: S
authors.initials: S
authors.lastname: Heck
authors.forename: T
authors.initials: T
authors.lastname: Graf
mesh_terms: D000818:Animals; D002469:Cell Separation; D005434:Flow Cytometry; D005453:Fluorescence; D015870:Gene Expression; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D005838:Genotype; D006098:Granulocytes / Q000166:cytology* / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006412:Hematopoietic Stem Cells / Q000166:cytology; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics*; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009113:Muramidase / Q000235:genetics*
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D009113:Muramidase