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...
In budding yeast, cohesins are central to maintain sister
chromatids cohesion and to shape the mitotic chromosomes. Here I'll
present our effort to model the interplay between cohesin-mediated
cohesion and loop extrusion and investigate how it shapes the
organization of mitotic chromosomes in yeast. By comparing model
predictions and Hi-C experimental data, we observe the signature...
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...
To decipher the mechanisms linking chromatin dynamics and the control of transcription, we combine high-throughput in vivo imaging of the whole nucleus and Brownian dynamics simulations. We compare the chromatin mean squared displacement obtained using our high resolution diffusing mapping on human mammary tumor cells, to the one measured on numerical simulations of chromatin with RNA...
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...
Although the cells of a multicellular organism share the same genetic material, their functions, structures, and behaviours can vary significantly. Many of these differences arise from distinct gene expression programs. Environmental cues are integrated and mediate epigenetic changes that regulate cell activity, differentiation and development. Cells sense their microenvironment not only...
Chromatin structure varies dramatically between cells, but the specific
motifs that underlie this organization remain poorly understood. Using
imaging-based chromatin tracing techniques, we visualized 3D chromatin
organization in mouse pancreatic tissue. We show that individual
chromatin traces can be decomposed into loop and domain chromatin
folding motifs (CFMs) using standard Latent...
In bacteria, low-copy-number replicons carry self-specific partition systems to ensure their faithful segregation. Among these systems, ParABS partition systems, consisting of a Walker-type ATPase (ParA) and a DNA-binding protein (ParB) along with parS centromere sites, are the most prevalent on plasmids and the only one present on chromosomes. ParB proteins, recently shown to belong to a...
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...
