Originally published as Genetics Published Articles Ahead of Print on April 19, 2007.

Genetics, Vol. 176, 95-113, May 2007, Copyright © 2007
doi:10.1534/genetics.107.071803

Suppressors of zyg-1 Define Regulators of Centrosome Duplication and Nuclear Association in Caenorhabditis elegans

Catherine A. Kemp1, Mi Hye Song1, Murali Krishna Addepalli2, Ginger Hunter and Kevin O'Connell3

Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892

3 Corresponding author: Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Dr., Room 2A07, Bethesda, MD 20892.
E-mail: kevino{at}intra.niddk.nih.gov

In Caenorhabditis elegans, the kinase ZYG-1 is required for centrosome duplication. To identify factors that interact with ZYG-1, we used a classical genetic approach and identified 21 szy (suppressor of zyg-1) genes that when mutated restore partial viability to a zyg-1 mutant. None of the suppressors render animals completely independent of zyg-1 activity and analysis of a subset of the suppressors indicates that all restore the normal process of centrosome duplication to zyg-1 mutants. Thirteen of these suppressor mutations confer phenotypes of their own and cytological examination reveals that these genes function in a variety of cellular processes including cell cycle timing, microtubule organization, cytokinesis, chromosome segregation, and centrosome morphology. Interestingly, several of the szy genes play a role in attaching the centrosome to the nuclear envelope. We have found that one such szy gene is sun-1, a gene encoding a nuclear envelope component. We further show that the role of SUN-1 in centrosome duplication is distinct from its role in attachment. Our approach has thus identified numerous candidate regulators of centrosome duplication and uncovered an unanticipated regulatory mechanism involving factors that tether the centrosome to the nucleus.


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Genetics 2007 176: NP. [Full Text]