Dresden 2017 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 25: Posters - Cytoskeletal Filaments

BP 25.5: Poster

Dienstag, 21. März 2017, 14:00–16:00, P2-EG

Modelling collective microtubule and kinetochore dynamics — •Felix Schwietert and Jan Kierfeld — TU Dortmund, Lehrstuhl für Theoretische Physik I

We investigate the cooperative dynamics of microtubules, which are elastically coupled to kinetochores in the mitotic spindle. The model includes the dynamic instability of microtubules, forces on microtubules and kinetochores from elastic linkers and, eventually, an external force on the kinetochore. We use stochastic simulations and analytical Fokker-Planck equations to analyze one hemisphere of the mitotic spindle consisting of an ensemble microtubules coupled to one kinetochore under constant external force. In simulations of this one-sided spindle model, kinetochore movement exhibits bistable behavior as a function of the applied force [1]. Solving the Fokker-Planck equations for the microtubule-kinetochore distance distribution, we can derive the bistable behavior analytically and obtain conditions for the occurrence of bistability. This allows us to quantify the bistable regime in the parameter plane of linker stiffness and microtubule numbers. The bistable behavior can explain stochastic chromosome oscillations in metaphase, which have been observed in several experiments.

[1] E. J. Banigan: Minimal model for collective kinetochore-microtubule dynamics. (2015) PNAS 112.41:12699-12704.