DE DIEULEVEULT Maud
University : Paris Sud - Paris XI
Jury :
- Président : Pr P. Capy
- Rapporteurs : Dr P. Ferrier, Ch. Muchardt
- Examinateurs : Dr U. Rogner, Dr E. Thevenot
- Directeur de thèse : M. Gérard
Summary
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Embryonic stem cells have the unique capacity to divide indefinitely and to differentiate in all cell types. They are promising for therapeutic applications for future treatments. Understanding the contribution of chromatin remodeler to the control of gene expression is critical to reach this goal. The Chd family which belongs to the SNF2 superfamily, contains nine members and represend about one third of the chromatin remodelers expressed in ES cells. Our aim was to identify the target genes of each remodeler, to understand how they are involved in transcription regulation and how they share chromatin regulation in ES. This large-scale study started with the tagging of each Chd. Using homologous recombination, we generated 9 ES cell lines each carring a tagged allele. The C-terminus of each gene was fused with a FLAG-HA tag. This tag allowed efficient chromatin immunoprecipitation for all the proteins. We performed tandem affinity chromatin IP for each protein. Immunoprecipitated DNA was sequenced onto an Illumina plateform in the lab of I. Gut (CEA/CNG and CNAG). We next analysed the transcriptome of Chd-depleted ES cells, using microarray hybridization and RNA-seq strategy. Our data show that NuRD (Chd4, Hdac2) is extensively involved in ES transcriptional pluripotency core network. Data obtained for Chd1, Chd8 and Chd4 show that each Chd has a particular binding pattern onto the mouse ES cell genome, suggesting different roles. However they regulated each other and belong to the same complexe core circuit. Finally, our results lead to new hypothesis to explain how Chd proteins contribute to genome regulation. |
Key-words : épigénétique gène genomique ChIP-seq remodelage chromatine CHD séquençage haut débit.