Microtubules get swept up in the excitement of mitosis

Microtubules (MTs) undergo a dramatic suctioning at the onset of mitosis, according to a report by Rusan et al. on page 997. The process places MTs in the vicinity of the growing mitotic spindle and may prevent nonspindle MTs from interfering with chromosome segregation.

Visualizing mitotic MT rearrangement has not been easy, because the process is so rapid. The new confocal videos of living cells expressing GFP-tubulin catch prophase in a way that imaging of fixed or microinjected cells never did. Rearrangement began in prophase with the depolymerization of cytosolic MTs and the formation of bundles and foci. Bundles were then pulled along other MTs extending from the centrosome. They continued to disassemble along the way, and eventually appeared to join with the forming spindle. A video of the entire process (which was completed...