title: The architecture of chicken chromosome territories changes during differentiation.
abstract: BACKGROUND
  Between cell divisions the chromatin fiber of each chromosome is restricted to a subvolume of the interphase cell nucleus called chromosome territory. The internal organization of these chromosome territories is still largely unknown.
  
  
  RESULTS
  We compared the large-scale chromatin structure of chromosome territories between several hematopoietic chicken cell types at various differentiation stages. Chromosome territories were labeled by fluorescence in situ hybridization in structurally preserved nuclei, recorded by confocal microscopy and evaluated visually and by quantitative image analysis. Chromosome territories in multipotent myeloid precursor cells appeared homogeneously stained and compact. The inactive lysozyme gene as well as the centromere of the lysozyme gene harboring chromosome located to the interior of the chromosome territory. In further differentiated cell types such as myeloblasts, macrophages and erythroblasts chromosome territories appeared increasingly diffuse, disaggregating to separable substructures. The lysozyme gene, which is gradually activated during the differentiation to activated macrophages, as well as the centromere were relocated increasingly to more external positions.
  
  
  CONCLUSIONS
  Our results reveal a cell type specific constitution of chromosome territories. The data suggest that a repositioning of chromosomal loci during differentiation may be a consequence of general changes in chromosome territory morphology, not necessarily related to transcriptional changes.
authors.affiliation: Department Biologie II, Biozentrum der Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany. sonja.Stadler@med.uni-muenchen.de <sonja.Stadler@med.uni-muenchen.de>
authors.forename: Sonja
authors.initials: S
authors.lastname: Stadler
authors.forename: Verena
authors.initials: V
authors.lastname: Schnapp
authors.forename: Robert
authors.initials: R
authors.lastname: Mayer
authors.forename: Stefan
authors.initials: S
authors.lastname: Stein
authors.forename: Christoph
authors.initials: C
authors.lastname: Cremer
authors.forename: Constanze
authors.initials: C
authors.lastname: Bonifer
authors.forename: Thomas
authors.initials: T
authors.lastname: Cremer
authors.forename: Steffen
authors.initials: S
authors.lastname: Dietzel
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D002467:Cell Nucleus / Q000648:ultrastructure; D002503:Centromere / Q000737:chemistry; D002645:Chickens / Q000235:genetics; D002875:Chromosomes / Q000737:chemistry / Q000648:ultrastructure*; D020868:Gene Silencing; D006570:Heterochromatin / Q000737:chemistry; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D009113:Muramidase / Q000235:genetics; D022423:Myeloid Cells / Q000166:cytology / Q000648:ultrastructure
chemical_list: D006570:Heterochromatin; D009113:Muramidase