Figure 7.
Spindle translocation in the absence of spindle elongation. Astral microtubules pull the nucleus into the bud in the absence of Kar9p (n = 9). (A). The spindle has elongated in the mother perpendicular to the mother-bud axis. N denotes the position of the neck, an arrow marks the end of the microtubule, and the spindle pole indicated by an asterisk. An astral microtubule from the SPB at 12 o'clock grows into the bud in the top three panels (0–60 s). Once the astral microtubule interacts with the bud cortex, there is net movement of the spindle toward the bud (90 s). (B). Graph of the microtubule length (open circles), spindle length (closed diamonds), and SPB movement (open triangles) as a function of time (sec). Movement of the SPBp into the bud is concomitant with astral microtubule interaction with the bud cortex. SPB movement is independent of spindle elongation.