title: Visualizing telomere dynamics in living mammalian cells using PNA probes.
abstract: Chromosome ends are protected from degradation by the presence of the highly repetitive hexanucleotide sequence of TTAGGG and associated proteins. These so-called telomeric complexes are suggested to play an important role in establishing a functional nuclear chromatin organization. Using peptide nucleic acid (PNA) probes, we studied the dynamic behavior of telomeric DNA repeats in living human osteosarcoma U2OS cells. A fluorescent cy3-labeled PNA probe was introduced in living cells by glass bead loading and was shown to specifically associate with telomeric DNA shortly afterwards. Telomere dynamics were imaged for several hours using digital fluorescence microscopy. While the majority of telomeres revealed constrained diffusive movement, individual telomeres in a human cell nucleus showed significant directional movements. Also, a subfraction of telomeres were shown to associate and dissociate, suggesting that in vivo telomere clusters are not stable but dynamic structures. Furthermore, telomeres were shown to associate with promyelocytic leukemia (PML) bodies in a dynamic manner.
authors.affiliation: Department of Molecular Cell Biology, Leiden University Medical Center, 2333 AL Leiden, The Netherlands.
authors.forename: Chris
authors.initials: C
authors.lastname: Molenaar
authors.forename: Karien
authors.initials: K
authors.lastname: Wiesmeijer
authors.forename: Nico P
authors.initials: NP
authors.lastname: Verwoerd
authors.forename: Shadi
authors.initials: S
authors.lastname: Khazen
authors.forename: Roland
authors.initials: R
authors.lastname: Eils
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Tanke
authors.forename: Roeland W
authors.initials: RW
authors.lastname: Dirks
mesh_terms: D001483:Base Sequence; D001859:Bone Neoplasms; D006801:Humans; D007700:Kinetics; D009068:Movement; D009693:Nucleic Acid Hybridization; D012516:Osteosarcoma; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D012091:Repetitive Sequences, Nucleic Acid; D016615:Telomere / Q000502:physiology* / Q000648:ultrastructure*; D014407:Tumor Cells, Cultured
chemical_list: D020135:Peptide Nucleic Acids