Dresden 2009 – scientific programme
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BP: Fachverband Biologische Physik
BP 17: Poster II
BP 17.2: Poster
Wednesday, March 25, 2009, 17:15–19:45, P3
Force Measurements in Mitotic Spindles — •Aaron Lindner1, Bastian Rühle1, Francois Nédelec2, and Joachim Spatz1,3 — 1University of Heidelberg — 2European Molecular Biology Laboratory, Heidelberg — 3MPI for Metals Research, Stuttgart
The mitotic spindle is responsible for chromosome alignment and segregation during cell division. It is a complex, microtubule-based assembly of different molecular motors and other proteins. In spite of its essential role in cell proliferation, the mechanics of mitotic spindles is not sufficiently well understood. In this project, the pulling strength of mitotic spindles will be determined experimentally.
Bipolar mitotic spindles can be assembled in vitro around chromatinylated, DNA covered microspheres in a cell-free model system which is gained from Xenopus laevis oocytes. In this work, the DNA covered microspheres are attached on functionalized polymer pillars. This yields a regular pattern of bipolar spindles on a force-sensing material.
Spindle pulling forces are expected to be in the range of one nanonewton, which is for the required geometric parameters below the detection limit of existing polymer pillar technologies. That is why for the first time the pillars were made of hydrogel. The Young's modulus of this hydrogel can be varied by altering the water content during polymerization. So it is possible to adjust the stiffness of the pillars to the experimental needs without changing the geometry. With this method, forces of less than 1nN can be detected by observing the pillar bending.