Bipolar, anastral spindle development in artificially activated sea urchin eggs
Article first published online: 4 APR 2008
Copyright © 2008 Wiley-Liss, Inc.
Volume 237, Issue 5, pages 1348–1358, May 2008
How to Cite
Henson, J. H., Fried, C. A., McClellan, M. K., Ader, J., Davis, J. E., Oldenbourg, R. and Simerly, C. R. (2008), Bipolar, anastral spindle development in artificially activated sea urchin eggs. Dev. Dyn., 237: 1348–1358. doi: 10.1002/dvdy.21533
- Issue published online: 21 APR 2008
- Article first published online: 4 APR 2008
- Manuscript Accepted: 2 MAR 2008
- The National Science Foundation. Grant Number: MRI/RUI 0320606
- Howard Hughes Medical Institute Undergraduate Science Education Program
- National Institutes of Health. Grant Numbers: NIBIB R01 EB002583, GM060925-2
- sea urchin;
The mitotic apparatus of the early sea urchin embryo is the archetype example of a centrosome-dominated, large aster spindle organized by means of the centriole of the fertilizing sperm. In this study, we tested the hypothesis that artificially activated sea urchin eggs possess the capacity to assemble the anastral, bipolar spindles present in many acentrosomal systems. Control fertilized Lytechinus pictus embryos and ammonia-activated eggs were immunolabeled for tubulin, centrosomal material, the spindle pole structuring protein NuMA and the mitotic kinesins MKLP1/Kinesin-6, Eg5/Kinesin-5, and KinI/Kinesin-13. Confocal imaging showed that a subset of ammonia-activated eggs contained bipolar “mini-spindles” that were anastral; displayed metaphase and anaphase-like stages; labeled for centrosomal material, NuMA, and the three mitotic kinesins; and were observed in living eggs using polarization optics. These results suggest that spindle structural and motor proteins have the ability to organize bipolar, anastral spindles in sea urchin eggs activated in the absence of the paternal centriole. Developmental Dynamics 237:1348-1358, 2008. © 2008 Wiley-Liss, Inc.