Figure 1.

Cytoplasmic microtubule behavior after spindle assembly in cdc28-4 clb5 haploids. Selected frames from a 35-min time-lapse series showing spindle orientation in cdc28-4 clb5 haploids expressing a GFP-Tub1 fusion (MYT126). Cytoplasmic microtubules emerging from either SPB interacted with the bud tip surface (small arrowheads), reflecting lack of spindle polarity as previously described for diploids (Segal et al., 2000). In addition, prominent neck interactions (large arrowheads) contributed to retention of the spindle at the neck. Neck region was defined as the cortex area within 0.5-μm distance of the point of constriction between the mother cell and the bud. Numbers indicate time elapsed in minutes. Bar, 2 μm.