title: Dynamic in vivo imaging and cell tracking using a histone fluorescent protein fusion in mice.
abstract: BACKGROUND
  Advances in optical imaging modalities and the continued evolution of genetically-encoded fluorescent proteins are coming together to facilitate the study of cell behavior at high resolution in living organisms. As a result, imaging using autofluorescent protein reporters is gaining popularity in mouse transgenic and targeted mutagenesis applications.
  
  
  RESULTS
  We have used embryonic stem cell-mediated transgenesis to label cells at sub-cellular resolution in vivo, and to evaluate fusion of a human histone protein to green fluorescent protein for ubiquitous fluorescent labeling of nucleosomes in mice. To this end we have generated embryonic stem cells and a corresponding strain of mice that is viable and fertile and exhibits widespread chromatin-localized reporter expression. High levels of transgene expression are maintained in a constitutive manner. Viability and fertility of homozygous transgenic animals demonstrates that this reporter is developmentally neutral and does not interfere with mitosis or meiosis.
  
  
  CONCLUSIONS
  Using various optical imaging modalities including wide-field, spinning disc confocal, and laser scanning confocal and multiphoton excitation microscopy, we can identify cells in various stages of the cell cycle. We can identify cells in interphase, cells undergoing mitosis or cell death. We demonstrate that this histone fusion reporter allows the direct visualization of active chromatin in situ. Since this reporter segments three-dimensional space, it permits the visualization of individual cells within a population, and so facilitates tracking cell position over time. It is therefore attractive for use in multidimensional studies of in vivo cell behavior and cell fate.
authors.affiliation: Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, 701 West 168th St,, New York, NY 10032, USA. hadj@mskcc.org
authors.forename: Anna-Katerina
authors.initials: AK
authors.lastname: Hadjantonakis
authors.forename: Virginia E
authors.initials: VE
authors.lastname: Papaioannou
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D017930:Genes, Reporter / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D008938:Mitosis; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000009:adverse effects / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D015996:Survival Rate
chemical_list: D006657:Histones; D009707:Nucleosomes; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins