Behavior of Microtubules in Cells

They showed that, in cultured animal cells, the bending of microtubules, labeled by fluorescence, is suppressed by the surrounding elastic cytoskeleton in cultured animal cells. Large intracellular forces cause significant bending fluctuations only on short length scales. However, these lateral bending fluctuations also naturally cause fluctuations in the orientation of the microtubule tip. During growth, these tip fluctuations lead to microtubule bends that are frozen-in by the surrounding elastic network, resulting in a persistent random walk of the microtubule, with a small apparent persistence length of ~30 m m, ~100 times smaller than that resulting from thermal fluctuations alone.

David A. Weitz (Physics & Applied Physics)
Lakshminarayanan Mahadevan (OEB, Physics, SEAS)
Harvard MRSEC (DMR-0820484)