This video corresponds to Fig. 3 B. Cleavage furrow induction in a grasshopper spermatocyte deprived of both asters and chromosomes. After micromanipulation, images were acquired every 2 min with a digital enhanced polarization microscope. Microtubules undergo disassembly-reassembly cycles and sometimes organize mono- or bipolar pseudospindles. However, pseudospindles are transient and eventually give rise to relatively disorganized microtubule bundles. Furrow induction occurs where the bundled microtubules are proximal to the cell cortex. The cell was fixed at the time of furrow initiation. The display rate is 10 frames/s.
