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Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes
Published on: December 20, 2014
Multiple mechanisms contribute to centriole separation in C. elegans.
Gabriela Cabral1, Sabina Sanegre Sans, Carrie R Cowan
1Max F. Perutz Laboratories, University of Vienna, Doktor-Bohr-Gasse 9, 1030 Vienna, Austria.
Current Biology : CB
|July 27, 2013
Summary
Separase is crucial for sperm centriole separation and duplication in C. elegans embryos. Cytoskeletal forces and pericentriolar material also play key roles in centriole separation during cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Developmental Biology
Background:
- Centrosome duplication ensures one centrosome per cell cycle, regulated by centriole assembly and separation.
- Vertebrate studies suggest separase protease mediates anaphase-coupled centriole separation, licensing new assembly.
- Separase is hypothesized to cleave a link, possibly cohesin, preventing premature centriole assembly initiation.
Purpose of the Study:
- To investigate the role of separase in centriole separation and duplication in the C. elegans early embryo.
- To understand the interplay between separase, cytoskeletal forces, and pericentriolar material in centriole disengagement.
Main Methods:
- Depletion of separase in C. elegans embryos.
- Analysis of sperm-derived and mitotic centriole separation and duplication.
- Manipulation of centrosomal microtubule nucleation and pericentriolar material disassembly.
Main Results:
- Separase depletion impairs sperm centriole separation and duplication at the meiosis-mitosis transition, but not in subsequent cycles.
- Sperm centrioles lack significant pericentriolar material and strong cytoskeletal forces, unlike mitotic centrioles.
- Increased microtubule nucleation rescues sperm centriole separation in separase-depleted embryos; forced pericentriolar material disassembly causes premature mitotic centriole separation.
Conclusions:
- Cytoskeletal forces and pericentriolar material are critical for centriole separation.
- Separase is essential for centriole separation in contexts with limited forces, explaining variations across experimental models.
- This study highlights the context-dependent mechanisms governing centriole disengagement and cell cycle progression.
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