title: Chromatin features of plant telomeric sequences at terminal vs. internal positions.
abstract: Epigenetic mechanisms are involved in regulation of crucial cellular processes in eukaryotic organisms. Data on the epigenetic features of plant telomeres and their epigenetic regulation were published mostly for Arabidopsis thaliana, in which the presence of interstitial telomeric repeats (ITRs) may interfere with genuine telomeres in most analyses. Here, we studied the epigenetic landscape and transcription of telomeres and ITRs in Nicotiana tabacum with long telomeres and no detectable ITRs, and in Ballantinia antipoda with large blocks of pericentromeric ITRs and relatively short telomeres. Chromatin of genuine telomeres displayed heterochromatic as well as euchromatic marks, while ITRs were just heterochromatic. Methylated cytosines were present at telomeres and ITRs, but showed a bias with more methylation toward distal telomere positions and different blocks of B. antipoda ITRs methylated to different levels. Telomeric transcripts TERRA (G-rich) and ARRET (C-rich) were identified in both plants and their levels varied among tissues with a maximum in blossoms. Plants with substantially different proportions of internally and terminally located telomeric repeats are instrumental in clarifying the chromatin status of telomeric repeats at distinct chromosome locations.
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Majerová
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Terezie
authors.initials: T
authors.lastname: Mandáková
authors.affiliation: Max Planck Institute for Plant Breeding Research Cologne, Germany.
authors.forename: Giang T H
authors.initials: GT
authors.lastname: Vu
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk University Brno, Czech Republic ; Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i. Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Fajkus
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lysak
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology and Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Miloslava
authors.initials: M
authors.lastname: Fojtová
keywords: Ballantinia antipoda; DNA methylation; Nicotiana tabacum; chromatin; epigenetics; histone modifications; telomere