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The centromere geometry essential for keeping mitosis error free is controlled by spindle forces
Jadranka Loncarek1, Olga Kisurina-Evgenieva, Tatiana Vinogradova
1Division of Molecular Medicine, Wadsworth Center, Albany, New York State Department of Health, Albany, New York 12201-0509, USA.
Nature
|November 30, 2007
Summary
Chromosome bi-orientation ensures genome stability. New research shows external forces, not just elasticity, are needed to correct syntelic attachments and maintain proper centromere architecture for accurate chromosome segregation.
Area of Science:
- Cell Biology
- Genetics
- Molecular Biology
Background:
- Accurate chromosome segregation is vital for genome stability.
- Bi-orientation, where each chromosome attaches to both spindle poles, is crucial.
- Syntelic attachments, where both sister kinetochores attach to one pole, must be corrected.
Purpose of the Study:
- To investigate the mechanism of syntelic attachment correction.
- To test the assumption that centromere architecture restoration is automatic.
- To determine the role of centromere shape in spindle assembly.
Main Methods:
- Laser microsurgery on cultured mammalian cells.
- Chemical biology assays.
- Microscopy and live-cell imaging.
Main Results:
- Kinetochores of syntelic chromosomes remain juxtaposed after detachment from microtubules.
- External forces are required to separate sister kinetochores on syntelic chromosomes.
- Centromere shape influences bipolar spindle formation, especially in centrosome-lacking cells.
Conclusions:
- Correction of syntelic attachments requires external forces, challenging the automatic restoration assumption.
- Proper centromere architecture is essential for high-fidelity chromosome segregation.
- Centromere shape plays a significant role in ensuring accurate spindle assembly.
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