The green urchin zygote has a diameter of about 160 µm. These large cells offer excellent spatial and temporal resolution for cytokinesis studies. This gallery of single focal plane confocal micrographs shows that during anaphase microtubules contact the cell poles before they contact the equator and that furrowing commonly initiates a little before microtubule tips touch the equatorial cortex. Comparison with the companion gallery for purple urchin zygotes, whose diameter is half that of the green urchin zygote shows that the smaller cells initiate cleavage earlier with respect to nuclear cycle phase and that when furrowing begins in purples microtubules are normally touching the equator. The final panel in this gallery displays a green urchin zygote and a purple urchin zygote, at the same magnification, both at incipient furrowing. All images were made with a BioRad Radiance 2000 laser scanning confocal microscope on a Nikon E800 microscope using a 60X 1.4 oil Plan Apo objective. Preparation protocol is described in Foe and von Dassow, 2008.
Please note: images on this page belong to Victoria Foe. You are welcome to use them in your own presentations/lectures with appropriate credit.
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