Fig. 3
From: Using sea urchin gametes and zygotes to investigate centrosome duplication
Second mitosis in a Lytechinus pictus zygote. This image shows use of the polarizing microscope to image spindles and asters in living zygotes of a sea urchin that has optically clear eggs. The spindles are negatively compensated and appear dark. Quadrants of the asters are bright because the microtubules in those quadrants are oriented at right angles to those of the central spindle. Scale divisions are 10 μm apart