Figure 5.

Spindle distribution by size and positioning in budded cells. Asynchronous parental MYT1010 (cdc28-4 GAL1: CLB5) or mutant MYT1416 (cdc28-4 clb5 GAL1:CLB5) diploids expressing the GFP:TUB1 fusion were shifted from galactose to dextrose-containing medium for 6 h before microscopy. (A) Distribution by size. At least 100 digitized images were captured and used for spindle measurements as described in Materials and Methods. Size intervals were as follows: <2 μm (black bars), 2–3 μm (white striped bars), 3–5 μm (black striped bars) and >5 μm (gray bars). Mean length and standard deviation for each size interval is indicated. (B) Distribution by position. At least 200 cells containing spindles shorter than 3 μm were scored by fluorescence microscopy. The proportion of cells containing the spindle in the mother cell (white bars), across the bud-neck (light gray bars), in the bud within 1 μm from the neck (dark gray bars), and in the bud farther than 1 μm away from the neck (black bars) are shown. The percentage of aligned spindles (as defined in C) with respect to the mother-bud axis is indicated for each position category. (C) Operative definition of spindle alignment. Aligned spindles were those within an angle of 35° (broken lines) with respect to the main mother–daughter axis (solid line).