Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 17: Posters: Physics of Cells
BP 17.23: Poster
Mittwoch, 28. März 2012, 17:30–19:30, Poster A
Mitotic Spindle Positioning by Cortical Force Generators — •Rui Ma1,2, Nenad Pavin3, Liedewij Laan4, Marileen Dogterom4, and Frank Jülicher1 — 1Max Planck Institute for the Physics of Complex Systems (MPI-PKS), Dresden, Germany — 2Institute for Advanced Study Tsinghua University, Beijing, China — 3Department of Physics, Faculty of Science, University of Zagreb, Zagreb 10002, Croatia — 4FOM Institute for Atomic and Molecular Physics (AMOLF), Science Park 104, 1098 XG Amsterdam, the Netherlands
In animal cells, the plane of cell division is determined by the position of the mitotic spindle. During asymmetric cell division of the C. elegans embryo the mitotic spindle is displaced away from the geometric cell center. This displacement results from the asymmetric activation of cortical force generators which pull on astral microtubules. We present a physical description of the interplay of pushing and pulling forces on astral microtubules in a three dimensional geometry. The Key element in this description is the fact that growing microtubules can slide along the cell cortex thus experiencing a pushing force. Once they are attached to a force generator, they would experience a pulling force before undergoing disassembly. We show that the net force acting on the pole depends on the angular distribution of astral microtubules which results from the combination of microtubule nucleation, growth, sliding and disassembly. Asymmetric activation of pulling force generators can lead to stable positioning of the the centrosome at positions displaced off the geometric center.