Mechanics & Dynamics of the Primary Cilium
von Christopher Battle
Datum der mündl. Prüfung:2013-06-25
Betreuer:Prof. Dr. Christoph F. Schmidt
Gutachter:Dr. Andreas Neef
Gutachter:Prof. Dr. Marcus Mueller
EnglischRecent studies have shown that the primary cilium, long thought to be a vestigial organelle with no function, is involved in a multitude of sensory functions. One example, interesting from both biophysical and medical standpoints, is the primary cilium of kidney epithelial cells, which acts as a mechanosensitive flow sensor. The mechanical properties of these non-motile, microtubule-based cilia and their anchorage to the cell cytoskeleton are important for understanding the cell's mechanosensitive response, which is mediated by the cilium. In order to explore this response, we built an epifluorescence microscope with optical trapping and patch clamping capabilities, and describe preliminary results. To probe the mechanical properties, cellular anchoring conditions, and dynamics of the cilia of Madin-Darby canine kidney epithelial cells, we built high-quality differential interference contrast microscopy capabilities into an existing dual-optical trap setup and wrote a custom MATLAB algorithm to track cilia dynamics. Experimentally determined values for the flexural rigidity of primary cilia are reported, as well as evidence for a hinged boundary condition at the cellular attachment point. Additionally, we find evidence of active, non-equilibrium behavior in the cilium's fluctuation dynamics.
Keywords: biophysics; cell mechanics; primary cilia