Orateur
Description
Claudie Carron1, Carine Dominique1, Nana Kadidia Maiga 1, Mickaël Lelek2, Thomas Mangeat3, Frédéric Beckouët1, Christian Rouvière3, Isabelle Léger-Silvestre1, Sylvain Cantaloube3, Christophe Zimmer2, Anthony K. Henras1, Benjamin Albert1and Olivier Gadal1.
1: MCD (CBI), Université de Toulouse, CNRS, UPS, 31000, Toulouse, France
2: Imaging and Modeling Unit, Department of Computational Biology, Institut Pasteur, Paris, France
3: Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31000, Toulouse, France
Spatial organisation of chromosomes is a key feature for genome stability, transcription and is required for proper mitotic segregation. Using a large panel of technics, ranging from imaging chromatin position and motion in living cells to chromosome capture technologies, underlying mechanisms responsible of genome organization are now actively explored.
In model organism such as Saccharomyces cerevisiae, in silico models of the entire genome have been developed. A model based on passively moving polymer chains and local tethering accounted for a large amount of experimental data. In my presentation, I will rapidly introduce success and limit of in silico model to predict global organisation of chromatin fibers observed by microscopic technics. We applied a multiscale imaging to directly confront in silico model to imaging dataset. Using four imaging technologies of increasing resolution from widefield fluorescent microscopy, random illumination microscopy, single molecule localization microscopy to electron microscopy, we could acquire high resolution imaging of yeast chromatin.
Next, focusing on ribosomal DNA, a genomic region associated with the largest nuclear compartment, the nucleolus, we will discuss how putative liquid-liquid phase separation and condensate formation can affect chromatin properties. The nucleolus is enriched in protein bearing intrinsically disordered regions (IDRs), and we focused on one type of IDR, named KKE/D domains. We will show that KKE/D has a dual function in nucleolar organization depending on transcriptional activities activity.
