Prof. David Holcman | Phase separation modeling and chromatin reconstruction

Speaker: Professor David Holcman (CNRS - Ecole Normale Superieure Paris)
Date: 13th Oct 2023 - 9:00 to 9:40
Venue: INI Seminar Room 1
Title: Phase separation modeling and chromatin reconstruction
Event: (SPLW03) Biological condensates: cellular mechanisms governed by phase transitions
Abstract: Phase separated domains (PSDs) are ubiquitous in cell biology, representing nanoregions of high molecular concentration. PSDs appear at diverse cellular domains, such as neuronal synapses but also in eukaryotic cell nucleus, limiting the access of transcription factors and thus preventing gene expression.
We will present here some properties of PSDs derived from polymer models. Increasing the number of cross-linkers generate a polymer condensation, preventing the access of diffusing molecules. To investigate how the PSDs restrict the motion of diffusing molecules, we estimate the mean residence and first escaping times. Finally, by computing the mean square displacement of single particle trajectories, we can reconstruct the properties of PSDs in term of a continuum range of anomalous exponents. To conclude, PSDs can result from a condensed chromatin, where the number of cross-linkers control the molecular access.