BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250708T154804EDT-6507n4Zx3v@132.216.98.100 DTSTAMP:20250708T194804Z DESCRIPTION:ºÚÁϲ»´òìÈ's Seminar Series in Quantitative Life Sciences and Medic ine\n Sponsored by CAMBAM\, QLS\, MiCM and the Ludmer Centre\n  \n\nTitle: M echanics\, topology and geometry of mammalian chromosomes and nuclei and t heir epigenetic modulation\n Speaker: John Marko\, Northwestern University \n When: Tuesday\, January 14\, 12-1pm \n Where: Montreal Neurological Insti tute\, deGrandpre Communications Centre\n\nAbstract: I will discuss studie s of the mechanics and structure of metaphase chromosomes and nuclei extra cted from mammalian cells using glass micropipettes. Using a combination o f mechanical\, biochemical and genetic approaches we have shown that the m etaphase chromosome is a 'chromatin gel'\, without a contiguous protein sc affold\, and via SMC2 siRNA experiments\, that condensin plays a major rol e as a 'crosslinker'. I will also discuss the 'loop-extrusion' model for e stablishment of chromatid structure\, with special attention to how it gen erates compaction of chromosomes along their length\, or 'lengthwise compa ction'\, and how this provides a mechanism for chromatid and chromosome in dividualization. I will then describe use of the same general approach to analyze the mechanics of mammalian G1 nuclei. The nucleus shows two distin ct mechanical responses: an initial chromatin-dominated elastic behavior\, followed by a stiffer\, lamin-dominated regime at larger extension. The l ow-force chromatin-based elasticity can be modulated by changing histone a cetylation and methylation\, and the morphology of the nucleus is impacted by these changes\, with heterochromatinization driving the nucleus to be stiffer and rounder\, and with euchromatinization destabilizing nuclear sh ape.\n DTSTART:20200114T170000Z DTEND:20200114T180000Z LOCATION:deGrandpre Communications Centre\, 3801 rue University\, Montreal\ , QC\, H3A 2B4\, CA\, Montreal Neurological Institute\, CA\, QC\, Montreal \, H3A 2B4\, 3801 rue University SUMMARY:Mechanics\, topology and geometry of mammalian chromosomes and nucl ei and their epigenetic modulation URL:/micm/channels/event/mechanics-topology-and-geomet ry-mammalian-chromosomes-and-nuclei-and-their-epigenetic-modulation-303904 END:VEVENT END:VCALENDAR