Regensburg 2025 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 25: Poster: Active Matter, Soft Matter, Fluids (joint session DY/CPP)
CPP 25.16: Poster
Wednesday, March 19, 2025, 10:00–12:00, P3
Thermodynamically consistent coarsening model of crossover placement in meiosis — •Marcel Ernst1, 2 and David Zwicker1 — 1Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany — 2Universität Göttingen, Germany
Crossovers play an important role in meiosis, ensuring correct segregation of homologous chromosomes and increasing genetic variability. A recently proposed model suggests that crossover placement is determined by biomolecular condensates that coarsen by exchange and diffusion of a protein along chromosomes, consistent with experiments. We here present an extended model including exchange with the nucleoplasm based on thermodynamic principles. We study theoretically and numerically the initial protein loading onto the chromosome, the droplet growth regime, the coarsening regime, and the final equilibrium. We derive scaling laws for the number of crossovers analogous to Lifshitz-Slyozov-Wagner theory in different limits. Finally, we investigate the effect of protein exchange with the nucleoplasm on crossover placement and compare the results with empirical data from several species. In conclusion, our model allows us to explain key features of meiotic crossover placement in wild type and several mutants.
Keywords: coarsening; chromosomes; phase separation; biomolecular condensates