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...
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...
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...
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...
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...
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...
