A single confocal-plane of a YFP::α-tubulin-expressing embryo imaged near the cell center. The spindle and radiating MTs are visible. MT fiber ends indicated by arrows were tracked to obtain contact time (see Fig. 2A).

Movie illustrating the imaging procedure: we first image the embryo by DIC until anaphase. At this point, the focus is shifted to the cortex, and fluorescence acquisition is started (in this case, a YFP::α-tubulin embryo). After 80 seconds of imaging, we return to DIC in order to verify that the cell cycle has progressed normally. Note that, as anaphase progresses, the number of ‘lines’ at the cell cortex increases.

Cortical imaging of a YFP::α-tubulin-expressing embryo. MTs appear alternatively on the right and left cortices, as a consequence of spindle oscillations in the tranverse plane that are, in this example, perpendicular to the imaging plane.

Cortical imaging on a EBP-2::GFP embryo.

A portion of an EBP-2::GFP embryo. The arrows indicate the ends of 2 MTs in the same fiber. Both MTs grow, following the same tracks.

End-on view of an YFP::α-tubulin embryo with oscillating posterior pole.

End-on view of an EBP-2::GFP embryo with oscillating posterior pole.

A 2D simulation of an aster oscillating in a circle.

A 3D simulation observed laterally.

A 3D simulation observed laterally of an embryo expressing EBP-2::GFP.

A 3D simulation observed from the posterior end.

A 3D simulation observed from the posterior end of an embryo expressing EBP-2::GFP.

Simulation of the cortical view of an embryo expressing YFP::α-tubulin.

Simulation of the cortical view of an embryo expressing EBP-2::GFP.

An anaphase embryo imaged in DIC, where yolk granules are prominently visible. 30 successive images are superimposed on each frame, showing that the yolk granules throughout the embryo move as the spindle oscillates. This shows that spindle motions drive the entire cytoplasmic fluid.