Supplemental Movies

This article contains the following supporting material:

• Supplemental Movie 01 - Confocal time-lapse of an egg microinjected with GFP-EB1 and imaged through mitosis and cytokinesis. The structure and dynamics of the spindle and asters are visible. At anaphase onset, the asters abruptly undergo elongation in all directions. The movie represents 35 minutes of time-lapse acquisition with frames captured every 30 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 02 - Confocal time-lapse of the mitotic spindle in a GFP-EB1 microinjected egg. GFP-EB1 is seen as a comet tail on the tips of elongating microtubules, and can therefore be used to visualize changes in microtubule dynamics as the cell undergoes cell-cycle transitions. The microtubules of the spindle and asters are highly dynamic during metaphase. After anaphase onset, the astral microtubules begin to elongate and GFP-EB1 decorated tips can be seen growing through the cytoplasm at an increased distance from the centrosomes. The movie represents 6 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 03 - Confocal time-lapse of astral microtubules elongating toward the cortex during anaphase of a GFP-EB1 microinjected egg. The movie represents 2 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 04 - Confocal time-lapse (GFP-EB1) of the mitotic spindle and astral microtubules directed toward the equatorial plane during furrow ingression. The movie represents 4 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 05 - Confocal time-lapse (GFP-EB1) during ingression of the cleavage furrow. The movie represents 2 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 06 - Confocal time-lapse of GFP-EB1 in a hexylene-glycol treated egg. The cell completes mitosis and cytokinesis. The mitotic apparatus becomes very robust during anaphase. Astral microtubules prominently extend toward the cortex in all directions prior to cytokinesis. The movie represents 15 minutes of time-lapse acquisition with frames captured every 30 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 07 - Confocal time-lapse of GFP-EB1 in a hexylene-glycol treated egg during cytokinesis. GFP-EB1 is seen to decorate astral microtubules along the length of their lattice, rather than just at the tips, suggesting increased stability compared to control, and prolonged periods of elongation. The movie represents 5 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 08 - Confocal time-lapse of GFP-EB1 in a taxol-treated egg. The mitotic apparatus is very dense with microtubules. Multiple cytasters appear to polymerize in the equatorial cortex, and some become incorporated into the mitotic apparatus. While the spindle elongates during anaphase, no cleavage furrow is formed. Some contractility is observed at sites of cortical microtubule polymerization. Telophase occurs and the cell becomes binucleate due to failure of cytokinesis. The movie represents 25 minutes of time-lapse acquisition with frames captured every 30 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 09 - Confocal time-lapse of GFP-EB1 in a taxol treated egg. Microtubule dynamics appear to be suppressed in taxol-treated eggs, as seen by diminished decoration of MTs by GFP-EB1 as mitosis progresses. Cortical cytasters form and become drawn into the mitotic apparatus. Cortical contractility is seen to be associated with sites of microtubule polymerization. The movie represents 3 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.
• Supplemental Movie 10 - Widefield time-lapse of a Hoechst-stained egg, microinjected with taxol against one half of the MA (lower half) during anaphase. Furrowing is suppressed on the taxol-injected side, suggesting that either the astral microtubules fail to contact the cortex on the injected side, or that their suppressed dynamics prevent induction of a cleavage furrow. Some cortical perturbation is observed, consistent with our observation of cytaster-associated contractility (Movies 8 and 9). The movie represents 5 minutes of time-lapse acquisition with frames captured every 30 seconds and presented at a rate of 20 frames per second.
• Supplemental Movie 11 - Widefield time-lapse of a Hoechst-stained egg, microinjected with taxol against one half of the MA (left half) during anaphase, and then manipulated with a glass microneedle in order to bring the injected side into contact with the cortex. The microneedle appears as a shadow through the center of the cell. Furrowing occurs on the taxol-injected side after micromanipulation of the MA to the cortex, suggesting that suppression of MT dynamics does not inhibit furrowing as long as contact can be established with the cortex. The movie represents 8 minutes of time-lapse acquisition with frames captured every 30 seconds and presented at a rate of 20 frames per second.
• Supplemental Movie 12 - Confocal time-lapse of a GFP-EB1 microinjected egg, treated with urethane. The spindle and asters remain highly dynamic throughout mitosis, and the asters fail to elongate during anaphase. No contact is ever established between the MTs and the cortex, and no furrow is ever formed. Spindle pole separation does not occur, as the two centrosomes remain at a constant distance throughout anaphase, suggesting a lack of anaphase B. The movie represents 6 minutes of time-lapse acquisition with frames captured every 5 seconds and presented at a rate of 10 frames per second.