Cinquième réunion annuelle du GDR Architecture et Dynamique du Noyau et des Génomes (ADN&G)

Liste des abstracts

8. Biophysical models of the genome structural organization

Marco Di Stefano (IGH)

The eukaryotic genome in interphase is organized in distinct layers. Chromosomes occupy different positions in the nucleus (chromosome territories) with limited overlaps and segregate into active (A) and inactive (B) compartments spanning several mega-bases (Mb) of DNA. At the sub-Mb level, chromatin is organized into self-interacting regions (topologically associating domains or TADs) and...

5. Chromatin State-Dependent Polymer Model: Bridging Nucleosome Positioning and Large-Scale Chromatin Organization

Elham Ghobadpour (TIMC-Grenoble university/ ENS-lyon)

Chromatin organization plays a crucial role in regulating genome accessibility and nuclear processes. My research focuses on nucleosome positioning and chromatin accessibility, extending polymer physics models to incorporate state-dependent chromatin properties. The structural and dynamic behavior of chromatin—such as bending rigidity, compaction, and accessibility—is modulated by biochemical...

7. Cohesin complex oligomerization maintains end-tethering at dna double-strand breaks.

karine dubrana (IRCM-CEA)

DNA double-strand breaks (DSBs) must be repaired to ensure genome stability. Crucially, DSB-ends must be kept together for timely repair. In Saccharomyces cerevisiae, two pathways mediate DSB end-tethering. One employs the Mre11–Rad50–Xrs2 (MRX) complex to physically bridge DSB-ends. Another requires the conversion of DSB-ends into single-strand DNA (ssDNA) by Exo1, but the bridging proteins...

2. Does the nuclear envelope’s structure and lipid composition impact genome stability?

Janélie Bâcle (CRBM, cnrs, Université de Montpellier)

The genome is compartmentalized from the rest of the cell by the nuclear envelope (NE), which consists of two concentric lipid bilayers separated by an inter-membrane space (IMS). The inner and the outer nuclear membranes (INM, ONM) face the nucleoplasm and the cytoplasm, respectively, and are maintained at a constant distance by bridging proteins demarcating the IMS. In humans, this bridging...

4. Epigenetic mechanisms and treatment approaches for Mantle Cell Lymphoma

Yelena Grishina (CNRS, UMR 9018, Université Paris-Saclay, Institut Gustave Roussy, 94800 Villejuif, France)

Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a poor prognosis. Over 90% of MCL cases are associated with a t(11;14) recurrent chromosomal translocation which drives the overexpression of cyclin D1 (CCND1), a critical regulator of the cell cycle. However, animal models show that CCND1 overexpression alone is insufficient to induce malignancy, suggesting that additional...

3. Genome-Wide Modeling of 3D Chromosome Organization in Yeast S-Phase

Dario D'Asaro (ENS-lyon)

From the basic structure of two diverging sister forks to their organization at the nuclear scale, the mechanistic details of how DNA replication influences 3D chromatin organization remain highly debated. To quantitatively address some of these questions, we simulate the entire Saccharomyces cerevisiae genome, integrating its 3D Rabl architecture with realistic 1D replication timing...

1. SUMO RNAi-mediated hyper-clustering of PRC1 results in the re-wiring of genome-wide TADs.

Nazli AKILLI

Polycomb group complexes (PcGs) are crucial regulators of genome organization in Drosophila, with PRC1—comprised of the subunits Pc, Ph, Psc, and Sce—playing an important role. PRC1 is integral to three-dimensional (3D) chromatin architecture and interacts with PRC2, which mediates the H3K27me3 mark. The clustering of PRC1 into foci, measuring 100 to 200 nm, is closely linked to its functional...

6. The ParB-CTP Cycle Activates Phase Separation in Bacterial DNA Segregation

Mlle Linda Delimi (Laboratoire Charles Coulomb)

Cell function relies on liquid-like organelles formed through phase transitions, yet the mechanisms ensuring their specificity and rapid assembly remain poorly understood. In bacterial chromosome segregation via the ParABS system, hundreds of ParB proteins are recruited around the centromere-like parS sequence forming the partition complex. Recent studies have shown that ParB binds CTP and...