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BP: Fachverband Biologische Physik

BP 7: Poster 1

BP 7.30: Poster

Montag, 5. September 2022, 18:00–20:00, P1

Altered local chromatin dynamics in stressed cells — •Rebecca Benelli and Matthias Weiss — Experimental Physics I, University of Bayreuth, Germany

The dynamic re-organization of chromatin is of crucial importance for cell viability and replication. During interphase, chromatin is mostly decondensed to allow for the transcription of genes, i.e. individual chromatin elements can be supposed to move like monomers of a polymer. Yet, recent reports have suggested chromatin to behave like a solid body on mesoscopic scales, questioning any free motion of chromatin elements. To explore the motion of integral chromatin markers, we have performed extensive single-particle tracking on telomeres under varying conditions. In agreement with previous findings, we observed a strongly subdiffusive and anti-persistent motion of telomeres in untreated culture cells, akin to the motion of monomers in a Rouse polymer. Reducing the ambient temperature or challenging cells by hyper- or hypo-osmotic stress resulted in a significant reduction of telomere mobility. In addition, significant jumps of telomeres between dynamically caged loci, observed in untreated cells, subsided or even vanished in response to these challenges. Altogether, our data indicate that local chromatin dynamics with long-range jumps between different loci are possible in untreated cells whereas a more compact/solid configuration of chromatin might explain the strongly reduced mobility of telomeres in stressed cells.