Microneedle manipulation to exert sustained force on the mammalian k-fiber, related to Fig. 1. Microneedle manipulation of individual k-fiber in metaphase PtK2 cell to probe how k-fibers dynamics and structure respond to sustained force. The microneedle (Alexa 555, yellow) exerts force for minutes and moves the spindle (kinetochores, Cdc20-YFP, green; tubulin, SiR-tubulin, magenta) and deforms k-fibers. Manipulated spindles typically progress to anaphase (here at 10:04). Scale bar, 4 µm. Video was collected using a spinning disk confocal microscope at one frame every 4 s. Video has been adjusted to play back at a constant rate of 30 frames/s. Video corresponds to still images from Fig. 1 D.
