Figure 2. Microtubule nucleation and release from the centrosome. In all three examples the centrosome is in the upper left corner of the frame and the MT traverses the nuclear-ventral zone. In the lower left corner of each frame is shown the time (seconds) at which the image was collected. The MT of interest is highlighted by a semitransparent red overlay. Minus and plus ends of the MT are labeled '-' and '+', repectively. Graphs below each sequence show the distance of the MT plus ('+', circles) and minus ('-', triangles) ends from the centrosome v. time. Vertical dotted lines indicate the times at which the frames were acquired. The distance of the plus end from the centrosome was measured along the contour of the MT. (A) MT is shown shortly after its nucleation at the centrosome until after its release (between 85-89 s) and movement across the nuclear-ventral region (>89 s). The plus end of the MT bends (105 s). (B) MT is released and the minus end moves away from centrosome while the plus end remains in the same position. Copyright © MT is released and moves away from the centrosome. The MT buckles (135 s) and begins to shorten, presumably from its minus end. Scale bar, 5 µm.