Figure 3.

Simultaneous penetration of astral microtubules in the bud in bud6 mutants. Bud6 mutants expressing dynein-GFP were visualized by fluorescence microscopy. The mother cell is in the bottom right quadrant, the daughter to the top left. Astral microtubules emanating from spindle pole bodies in the mother (8 and 10 o'clock respectively) cross over the neck and penetrate the bud simultaneously. These defects were observed in 3/18 bud6 mutants for a total of 3.7 percentage of the time before anaphase onset (8 min of alternating cycles of microtubule polymerization/depolymerization in the bud emanating from each pole, 30 s where microtubules from both poles penetrate the bud; 230 total minutes). 5/20 bni1 mutants exhibited dual penetration from both spindle poles for 8.1% of the time (50/617 total min) and 2/11 kar9 mutants for a total duration of 1.6% of the time before anaphase onset (7.5/464 total min).