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Updated: Jun 18, 2026
10:09
Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes
Published on: September 13, 2022
The spindle position checkpoint requires positional feedback from cytoplasmic microtubules
Jeffrey K Moore1, Valentin Magidson, Alexey Khodjakov
1Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, MO 63110, USA.
Current Biology : CB
|November 17, 2009
Summary
The spindle position checkpoint ensures accurate genome delivery during cell division. Cytoplasmic microtubules interacting with the bud neck are crucial for this process, preventing premature cell division.
Area of Science:
- Cell Biology
- Genetics
- Microscopy
Background:
- Mitosis ensures each daughter cell receives a complete genome copy.
- Accurate chromosome segregation relies on spindle apparatus function.
- Budding yeast utilize a spindle position checkpoint for faithful chromosome delivery.
Purpose of the Study:
- To investigate the role of cytoplasmic microtubules in the spindle position checkpoint.
- To test if microtubule interactions with the bud neck are essential for checkpoint activity.
Main Methods:
- Utilized laser ablation to disrupt microtubule-bud neck interactions in budding yeast.
- Observed effects of microtubule disruption on mitotic exit timing.
Main Results:
- Loss of microtubules from the bud neck caused premature mitotic exit in checkpoint-activated cells.
- Disruption of microtubule-bud neck interactions abrogated checkpoint control.
Conclusions:
- Cytoplasmic microtubules act as sensors for spindle position.
- Microtubules relay signals to inhibit mitotic exit until proper spindle placement.
- This mechanism ensures accurate genome distribution to daughter cells.
Related Concept Videos
02:19The Spindle Assembly Checkpoint
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
02:19The Spindle Assembly Checkpoint
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
02:50Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
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02:27The Mitotic Spindle
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The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
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02:27The Mitotic Spindle
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02:11Forces Acting on Chromosomes
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
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