BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Prof. Dr. Giacomo Cavalli (Institute of Human Genetics) DTSTART:20210115T090000Z DTEND:20210115T100000Z DTSTAMP:20260423T022805Z UID:MCB_LUMS/10 DESCRIPTION:Title: Principles and functional role of 3D genome folding\nby Prof. Dr. Gi acomo Cavalli (Institute of Human Genetics) as part of Colloquium zooming Molecular & Cellular Biology LUMS\n\n\nAbstract\nThe eukaryotic genome fol ds in 3D in a hierarchy of structures\, including nucleosomes\, chromatin fibers\, loops\, chromosomal domains (also called TADs)\, compartments and chromosome territories that are highly organized in order to allow for st able memory as well as for regulatory plasticity\, depending on intrinsic and environmental cues. Our lab has provided evidence suggesting that the formation of TADs and chromatin loops can assist gene regulation\, both in Drosophila and in mouse cells. Furthermore\, cellular stress\, such as re plicative or oncogene-induced senescence\, can induce a massive nuclear re organization that can affect gene expression. However\, the physical natur e of compartments\, TADs and loops remain elusive and single-cell studies are critically required to understand it. We characterized chromatin foldi ng in single cells using super-resolution microscopy\, revealing structura l features inaccessible to cell-population analysis. TADs range from conde nsed and globular objects to stretched conformations. The physical insulat ion associated with their borders is variable between individual cells\, y et chromatin intermingling is enriched within TADs compared to adjacent TA Ds in a large majority of cells. The spatial segregation of TADs is furthe r exacerbated during cell differentiation. Favored interactions within TAD s are regulated by cohesin and CTCF through distinct mechanisms. Furthermo re\, super-resolution imaging revealed that TADs are subdivided into discr ete nanodomains. Altogether\, these results provide a physical basis for t he folding of individual chromosomes at the nanoscale. Our progress in the se fields will be discussed.\n LOCATION:https://researchseminars.org/talk/MCB_LUMS/10/ END:VEVENT END:VCALENDAR