PT - JOURNAL ARTICLE AU - Martine Chebrout AU - Maimouna Coura Kone AU - Habib U. Jan AU - Marie Cournut AU - Martine Letheule AU - Renaud Fleurot AU - Tiphaine Aguirre-Lavin AU - Nathalie Peynot AU - Alice Jouneau AU - Nathalie Beaujean AU - Amélie Bonnet-Garnier TI - rDNA nascent transcripts promote a unique spatial organization during mouse early development AID - 10.1101/2021.04.20.440564 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.04.20.440564 4099 - http://biorxiv.org/content/early/2021/04/21/2021.04.20.440564.short 4100 - http://biorxiv.org/content/early/2021/04/21/2021.04.20.440564.full AB - During the first cell cycles of the early development, the chromatin of the embryo is highly reprogrammed alongside that embryonic genome starts its own transcription. The spatial organization of the genome is a major process that contributes to regulating gene transcription in time and space, however, it is poorly studied in the context of early embryos. To study the cause and effect link between transcription and spatial organization in embryos, we focused on the ribosomal genes, that are first silent and begin to transcribe during the 2-cell stage in mouse. We demonstrated that ribosomal sequences are spatially organized in a very peculiar manner from the 2-cell to the 16-cell stage with transcription and processing of ribosomal RNAs excluding mutually. Using drugs inhibiting the RNA polymerase I, we show that this organization, totally different from somatic cells, depends on an active transcription of ribosomal genes and induces a unique chromatin environment that favors major satellite sequences transcription after the 4-cell stage.Competing Interest StatementThe authors have declared no competing interest.Abbreviations5’ETS5’ externally transcribed spacerActDActinomycin DEGAEmbryonic Genome ActivationhphCGhours post-injection of human Chorionic GonadotrophinH3K9acHistone 3 acetylated in lysine 9H3K4me3Histone 3 tri-methylated in lysine 4ITS1internal transcribed spacer 1ITS2internal transcribed spacer 2Major satmouse major satellite sequencesNPBNucleolar Precursor BodyNopp140Nucleolar phosphoprotein of 140 kDmPNmaternal pronucleuspPNpaternal pronucleusPVPPoly Vinyl PyrrolidoneRT-qPCRReal-Time quantitative PCRRNA polymerase IRNA pol IrDNAribosomal DNA genes/sequencesrRNAribosomal RNAUBFUpstream Binding Factor