Geometric model for dynamics of motor-driven centrosomal asters

The centrosomal aster is a mobile and adaptable cellular organelle that exerts and transmits forces necessary for tasks such as nuclear migration and spindle positioning. Recent experimental and theoretical studies of nematode and human cells demonstrate that pulling forces on asters by cortically a...

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Main Authors: Yuan-Nan Young, Vicente Gomez Herrera, Huan Zhang, Reza Farhadifar, Michael J. Shelley
Format: Article
Language:English
Published: American Physical Society 2025-01-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.013004
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author Yuan-Nan Young
Vicente Gomez Herrera
Huan Zhang
Reza Farhadifar
Michael J. Shelley
author_facet Yuan-Nan Young
Vicente Gomez Herrera
Huan Zhang
Reza Farhadifar
Michael J. Shelley
author_sort Yuan-Nan Young
collection DOAJ
description The centrosomal aster is a mobile and adaptable cellular organelle that exerts and transmits forces necessary for tasks such as nuclear migration and spindle positioning. Recent experimental and theoretical studies of nematode and human cells demonstrate that pulling forces on asters by cortically anchored force generators are dominant during such processes. Here, we present a comprehensive investigation of the S-model (S for stoichiometry) of aster dynamics based solely on such forces. The model evolves the astral centrosome position, a probability field of cell-surface motor occupancy by centrosomal microtubules (under an assumption of stoichiometric binding), and free boundaries of unattached, growing microtubules. We show how cell shape affects the stability of centering of the aster, and its transition to oscillations with increasing motor number. Seeking to understand observations in single-cell nematode embryos, we use highly accurate simulations to examine the nonlinear structures of the bifurcations, and demonstrate the importance of binding domain overlap to interpreting genetic perturbation experiments. We find a generally rich dynamical landscape, dependent upon cell shape, such as internal constant-velocity equatorial orbits of asters that can be seen as traveling wave solutions. Finally, we study the interactions of multiple asters which we demonstrate an effective mutual repulsion due to their competition for surface force generators. We find, amazingly, that centrosomes can relax onto the vertices of platonic and nonplatonic solids, very closely mirroring the results of the classical Thomson problem for energy-minimizing configurations of electrons constrained to a sphere and interacting via repulsive Coulomb potentials. Our findings both explain experimental observations, providing insights into the mechanisms governing spindle positioning and cell division dynamics, and show the possibility of new nonlinear phenomena in cell biology.
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spelling doaj-art-6d9afb7dbbac4a849275949dd8fafc192025-01-03T15:07:53ZengAmerican Physical SocietyPhysical Review Research2643-15642025-01-017101300410.1103/PhysRevResearch.7.013004Geometric model for dynamics of motor-driven centrosomal astersYuan-Nan YoungVicente Gomez HerreraHuan ZhangReza FarhadifarMichael J. ShelleyThe centrosomal aster is a mobile and adaptable cellular organelle that exerts and transmits forces necessary for tasks such as nuclear migration and spindle positioning. Recent experimental and theoretical studies of nematode and human cells demonstrate that pulling forces on asters by cortically anchored force generators are dominant during such processes. Here, we present a comprehensive investigation of the S-model (S for stoichiometry) of aster dynamics based solely on such forces. The model evolves the astral centrosome position, a probability field of cell-surface motor occupancy by centrosomal microtubules (under an assumption of stoichiometric binding), and free boundaries of unattached, growing microtubules. We show how cell shape affects the stability of centering of the aster, and its transition to oscillations with increasing motor number. Seeking to understand observations in single-cell nematode embryos, we use highly accurate simulations to examine the nonlinear structures of the bifurcations, and demonstrate the importance of binding domain overlap to interpreting genetic perturbation experiments. We find a generally rich dynamical landscape, dependent upon cell shape, such as internal constant-velocity equatorial orbits of asters that can be seen as traveling wave solutions. Finally, we study the interactions of multiple asters which we demonstrate an effective mutual repulsion due to their competition for surface force generators. We find, amazingly, that centrosomes can relax onto the vertices of platonic and nonplatonic solids, very closely mirroring the results of the classical Thomson problem for energy-minimizing configurations of electrons constrained to a sphere and interacting via repulsive Coulomb potentials. Our findings both explain experimental observations, providing insights into the mechanisms governing spindle positioning and cell division dynamics, and show the possibility of new nonlinear phenomena in cell biology.http://doi.org/10.1103/PhysRevResearch.7.013004
spellingShingle Yuan-Nan Young
Vicente Gomez Herrera
Huan Zhang
Reza Farhadifar
Michael J. Shelley
Geometric model for dynamics of motor-driven centrosomal asters
Physical Review Research
title Geometric model for dynamics of motor-driven centrosomal asters
title_full Geometric model for dynamics of motor-driven centrosomal asters
title_fullStr Geometric model for dynamics of motor-driven centrosomal asters
title_full_unstemmed Geometric model for dynamics of motor-driven centrosomal asters
title_short Geometric model for dynamics of motor-driven centrosomal asters
title_sort geometric model for dynamics of motor driven centrosomal asters
url http://doi.org/10.1103/PhysRevResearch.7.013004
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AT rezafarhadifar geometricmodelfordynamicsofmotordrivencentrosomalasters
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