Chromosome methylation patterns during mammalian preimplantation development
- Nathalie Rougier1,
- Déborah Bourc’his1,
- Denise Molina Gomes1,
- Alain Niveleau2,
- Michelle Plachot3,
- Andràs Pàldi4, and
- Evani Viegas-Péquignot1,5
- 1U 383 Institut National de la Santé et de la Recherche Médicale (INSERM), and 3Laboratoire de Fécondation in Vitro Hôpital, Necker-Enfants Malades, 75743 Paris Cedex 15, France; 2Centre National de la Recherche Scientifique (CNRS), Université J. Fourier de Grenoble, 38706 La Tronche, France; 4U 257 INSERM, Institut Cochin de Génétique Moléculaire (ICGM), Centre Hospitalier Universitaire-Cochin, 75014 Paris, France
Abstract
DNA methylation patterns were evaluated during preimplantation mouse development by analyzing the binding of monoclonal antibody to 5-methylcytosine (5-MeC) on metaphase chromosomes. Specific chromosome patterns were observed in each cell stage. A banding pattern predominated in chromosomes at the one-cell stage. Banding was replaced at the two-cell stage by an asymmetrical labeling of the sister chromatids. Then, the proportion of asymmetrical chromosomes decreased by one-half at each cell division until the blastocyst stage, and chromosomes became progressively symmetrical and weakly labeled. Our results indicate that chromosome demethylation is associated with each DNA replication and suggest that a passive mechanism predominates during early development.
Keywords
Footnotes
-
↵5 Corresponding author.
-
E-MAIL viegas{at}ceylan.necker.fr; FAX +331 47 83 32 06.
-
- Received March 2, 1998.
- Accepted April 30, 1998.
- Cold Spring Harbor Laboratory Press
