UMMS Affiliation

Department of Cell Biology

Publication Date


Document Type



Anaphase; Animals; CDC28 Protein Kinase, S cerevisiae; Cell Nucleus; Centrosome; Female; Male; Metaphase; Microscopy, Electron; Mitosis; Prophase; Protein Biosynthesis; Protein Kinases; Protein Synthesis Inhibitors; Reproduction; S Phase; Sea Urchins; Zygote


Cell Biology | Life Sciences | Medicine and Health Sciences


Centrosomes repeatedly reproduce in sea urchin zygotes arrested in S phase, whether cyclin-dependent kinase 1-cyclin B (Cdk1-B) activity remains at prefertilization levels or rises to mitotic values. In contrast, when zygotes are arrested in mitosis using cyclin B Delta-90, anaphase occurs at the normal time, yet centrosomes do not reproduce. Together, these results reveal the cell cycle stage specificity for centrosome reproduction and demonstrate that neither the level nor the cycling of Cdk1-B activity coordinate centrosome reproduction with nuclear events. In addition, the proteolytic events of the metaphase-anaphase transition do not control when centrosomes duplicate. When we block protein synthesis at first prophase, the zygotes divide and arrest before second S phase. Both blastomeres contain just two complete centrosomes, which indicates that the cytoplasmic conditions between mitosis and S phase support centrosome reproduction. However, the fact that these daughter centrosomes do not reproduce again under such supportive conditions suggests that they are lacking a component required for reproduction. The repeated reproduction of centrosomes during S phase arrest points to the existence of a necessary "licensing" event that restores this component to daughter centrosomes during S phase, preparing them to reproduce in the next cell cycle.

DOI of Published Version



J Cell Biol. 1998 Mar 23;140(6):1417-26. Link to article on publisher's website

Journal/Book/Conference Title

The Journal of cell biology

Related Resources

Link to Article in PubMed

PubMed ID