Architectural reorganization of the nuclei upon transfer into oocytes accompanies genome reprogramming

Authors

  • Catherine Martin,

    1. UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
    2. Department Biologie II, Ludwig Maximillian Universität München, Planneg-Martinsried, Germany
    Search for more papers by this author
  • Vincent Brochard,

    1. UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
    Search for more papers by this author
  • Carole Migné,

    1. UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
    Search for more papers by this author
  • Daniele Zink,

    1. Department Biologie II, Ludwig Maximillian Universität München, Planneg-Martinsried, Germany
    Search for more papers by this author
  • Pascale Debey,

    1. UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
    2. UMR 8646 CNRS, UMR 5153 INSERM, Régulation et Dynamique des Génomes, Muséum National d'Histoire Naturelle, Case Postale 26, Paris, France
    Search for more papers by this author
  • Nathalie Beaujean

    Corresponding author
    1. UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
    • UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, 78352 Jouy-en-Josas, France.
    Search for more papers by this author

Abstract

The ability of cloned embryos to sustain full-term development depends on the ability of the recipient ooplasm to reprogram the donor cell genome. As the nuclear architecture has recently emerged as a key-factor in the regulation of gene expression, we questioned whether early embryos obtained from transfer of ES metaphasic chromosomes into mouse ooplasm would adopt the somatic or embryonic type of nuclear organization. We have particularly focused on the arrangement of chromosomal territories with respect to the nucleolar compartment, and the pericentric heterochromatin domains called chromocenters. We found that nuclear transfer triggers profound chromatin rearrangements including the dispersion of the donor cell chromocenters components. These rearrangements lead to a typical 1-cell pronuclear organization, namely a radial arrangement of the chromosome territories with centromeres attached to the nucleoli, which adopt the compact fibrillar structure of nucleolar precursor bodies (NPBs). Subsequently, during the second cycle, the cloned embryos undergo further reorganization with the establishment of new chromocenters, clustered in one part of the nucleus, as during normal embryogenesis. We could also establish that the adequate distribution of chromosomal territories at the pronuclear stage seems important for the development until blastocyst. Mol. Reprod. Dev. 1102–1111, 2006. © 2006 Wiley-Liss, Inc.

Ancillary