Sciences Animales Paris-Saclay
BREED J Cell Sci - Chebrout & al. publication
Accueil
Our research
No translated name
No translated name
BREED J Cell Sci - Chebrout & al. publication

Chromatin transcription and reorganisation go hand in hand

We showed that ribosomal genes (rDNA) are organized in a unique manner in the embryo (very differently than somatic cells) between the 4-cell and 16-cell stages and that this organization depends on their transcription state. We also showed that they could participate in the establishment of an environment that is favorable for the transcription of major satellite sequences - repeated sequences that are normally silent since they are located on the peri-centromeric heterochromatin.

During early development, pre-implantation mammalian embryos dynamically reprogram gene transcription and nuclear organisation. However, the causal relation between these two processes are the object of intense debates. To answer this question, we studied the spatial position and the transcription of ribosomal DNA sequences (rDNA) and repeated neighboring sequences. Initially these two types of sequences are positionned around the nucleolus precursor (NPB), superposed structures that play a role in the remodeling of chromatin during early development in mice. By combining DNA-3D-FISH and RNA-FISH, we found a unique organization for the rDNA inside the NPB, which is associated with the rDNA transcription state; the inhibition of this transcription leads to drastic changes in their organization. Finally, we showed that the disturbance of this 3D organization leads to a reduced thranscription of neighbor satellite repeats, suggesting that the reorganization of the chromatin during rRNA transcription provides an environment that facilitates expression of major repeat satellites. In conclusion, thiq study provides new important information on the interaction between the 3D nuclear structure and transcription.

Contact :

See also

Reference:
Martine Chebrout, Maïmouna Coura Koné, Habib U. Jan, Marie Cournut, Martine Letheule, Renaud Fleurot, Tiphaine Aguirre-Lavin, Nathalie Peynot, Alice Jouneau, Nathalie Beaujean, Amélie Bonnet-Garnier; Transcription of rRNA in early mouse embryos promotes chromatin reorganization and expression of major satellite repeats. J Cell Sci 15 March 2022; 135 (6): jcs258798. doi: https://doi.org/10.1242/jcs.258798

Modification date: 14 September 2023 | Publication date: 05 April 2022 | By: BREED - Edition P. Huan - Translation W. Brand-Williams