Neuvième réunion annuelle du GDR ADN (Architecture et Dynamique Nucléaires)

Liste des abstracts

27. 3D genome organization and the genetic risk to (some) diseases

Mme Annick Lesne (CNRS, LPTMC (Paris) & IGMM (Montpellier))

Genome-wide association studies have established statistical associations between various diseases and a large number of single-nucleotide polymorphisms (SNPs). However, they provided no simple explanation of the mechanisms underlying this association.  Following the idea that 3D genome organization and its variations may have a functional role in gene regulation, we investigated the...

28. Cell type specific chromatin domain organization reflects transcriptional competence in human mammary tumor cells

Dr Silvia Kocanova (Centre de Biologie Intégrative, CNRS, Toulouse)

The spatial organization of chromatin in the nucleus is non-random and chromatin dynamics participate in regulating essential nuclear processes. 3D genome organization is a ‘moderator’ of long range interactions, in particular between regulatory elements such as enhancer-promoter contacts. Chromatin folding is thought to contribute to transcriptional regulation within topologically constrained...

31. Global and ancestral regulation by DNA supercoiling is tuned by promoters’structure

M. Raphaël Forquet (MAP-UMR5240)

Usual models of transcriptional regulation are centered on transcription factors, which recognize specific sequences in genes’ promoters. However, at a more global scale, the physical state of the double helix, embedded in the chromatin fibre, plays a crucial role in genes’ expression in vivo. In particular, torsional stress (or DNA supercoiling) is an ubiquitous feature in DNA transactions,...

32. Modeling supercoiled DNA interacting with an anchored cluster of proteins: towards a quantitative estimation of chromosomal DNA supercoiling

Dr Jean-Charles WALTER (CNRS & Université de Montpellier)

DNA supercoiling, under or overwinding of DNA, is a key physical mechanism both
participating to compaction of bacterial DNA and to the coordination of gene expression. Methods developed so far can only measure it in small plasmids. Thus the distribution of supercoiling along chromosomes remains poorly understood. Here we aim at solving this problem by confronting (i) the folding physical...

29. phase separation scenario of the formation of the bacterial nucleoid

Marc Joyeux (LIPHY (CNRS et Université Grenoble Alpes))

The mechanism responsible for the compaction of the genomic DNA of bacteria inside a structure called the nucleoid is a longstanding but still lively debated question. Most puzzling is the fact that the nucleoid occupies only a small fraction of the cell, although it is not separated from the rest of the cytoplasm by any membrane and would occupy a volume about thousand times larger outside...

33. Physical nature of DNA repair foci revealed by single molecule microscopy

judith Miné-Hattab (Institut Curie, PSL Research University, CNRS, UMR3664)

Our genome is constantly damaged by a variety of exogenous and endogenous agents. Among the various forms of DNA damage, double-strand breaks (DSBs) are the most cytotoxic and genotoxic for the cell. Eukaryotic organisms use several mechanisms to repair DSBs among them non-homologous end-joining (NHEJ) and homologous recombination (HR).

Here, **we investigate the molecular mechanisms of HR...

30. The histone H3.3 chaperone DAXX contributes to heterochromatin organization and protects genome integrity of pluripotent cells.

Pierre Therizols (UMR INSERM 944, CNRS 7212)

Within the nucleus, heterochromatin domains segregate in particular compartments such as the chromocenters that contain pericentromeric heterochromatin (PCH) regions, or the lamina-associated domains (LADs) that localize at the periphery of the nucleus. In most cell types, DNA methylation is essential for heterochromatin formation, directly contributing to the transcriptional repression of DNA...