Céline Morey
  • E-mail :[email]
  • Phone : +33 1 45 68 86 53
  • Location : Paris, France
Last update 2011-03-30 14:49:13.363

Céline Morey PhD, Cell Biology

Course and current status

1999-2004     Doctoral studies on mouse X-chromosome inactivation. Mouse Molecular Genetics Unit (Avner’s laboratory), Pasteur Institute, Paris.

2004     Ph.D in Cellular and Molecular Biology, Paris 5 University, Paris.

2004-2007 Post-doctoral studies on nuclear reorganisation of HoxB and HoxD clusters during ES cell differentiation and mouse development. W. Bickmore’s laboratory, Chromosome and Gene Expression Section, MRC-Human Genetics Unit, Edinburgh, UK. 

Since 2008 Staff scientist (CR2 with the INSERM)

Research topic: Interplay between gene expression, chromatin structure and nuclear organisation during X-chromosome inactivation in mouse pre-implantation embryos;  Mouse Molecular Genetics Unit, Pasteur Institute, Paris.

Scientific summary

Although the sequence of the entire human genome is now available, we are still far from understanding how this code is read and executed during embryo development to give rise to the adult organism. The current view is that the undifferentiated-pluripotent state is not only ensured by activation and repression of key transcription factors but also by epigenetic modifications including specific replication profiles, chromatin signatures and nuclear organisation that facilitate the subsequent establishment of gene expression patterns specific for each cell lineage. Indeed, during the first differentiation steps, transcriptional genome programming is accompanied by large-scale epigenetic reorganisations. The challenge is now to unravel the relationships between a given genomic sequence, multiple potential epigenomes and cell lineage commitments. Recent efforts have focussed using genome-wide studies, on analysing how epigenetic marks are distributed in relation to features such as active or inactive promoters/enhancers and how they vary in different developmental or disease (cancer) states. We apply this “systems biology” approach to the process of X-chromosome inactivation during mouse pre-implantation development.

Genome-wide approaches are most often performed on tissues or on supposedly homogeneous cell populations, which provide abundant amounts of biological material. The context of the developing embryo, where cell differentiation and associated heterogeneisation of the initial cell pool is continuously at work, requires that we be able to follow in real time, and in each embryonic cell, the changes occurring at each of the various levels of regulation. Studying x-chromosome inactivation moreover requires yet an additional level of resolution: the capacity to distinguish the maternal from the paternal loci. We are developping a high-throughput 3D imaging and modelling of single chromatin fibres as an approach to these experimental constraints. Whilst for our biochemical studies, we drastically reduce the number of cells required (500-2000) and make use of SNPs (Single Nucleotide Polymorphisms) differentiating maternal from paternal haplotypes. These implementations allow us to move towards the single locus/single cell resolution.

Using this combination of approaches, we are characterising the X-chromosome plasticity of the different stem cells constitutive of the pre-implantation embryo. Such studies will improve our understanding of the regulation of genome plasticity in embryonic and extra-embryonic stem cells which represent a prerequisite to the use of these cells in therapeutic strategies.

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