Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

The Spindle Assembly Checkpoint

The 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...

The Spindle Assembly Checkpoint

The 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...

Spindle Assembly

Spindle 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...

The Mitotic Spindle

The Mitotic Spindle

The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...

The Mitotic Spindle

The Mitotic Spindle

The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...

DNA Damage can Stall the Cell Cycle

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Eliminating separase inhibition reveals absence of robust cohesin protection in oocyte metaphase II.

The EMBO journal·2025

Same author

Prolonged metaphase II arrest weakens Aurora B/C-dependent error correction in mouse oocytes.

Current biology : CB·2025

Same author

Microbiological and molecular screening of <i>Candida</i> spp. isolated from genital tract of asymptomatic pregnant women.

Journal of medical microbiology·2022

Same author

Aurora B/C-dependent phosphorylation promotes Rec8 cleavage in mammalian oocytes.

Current biology : CB·2022

Same author

Kinetochore individualization in meiosis I is required for centromeric cohesin removal in meiosis II.

The EMBO journal·2021

Same author

Immunostaining of Whole-Mount Drosophila Testes for 3D Confocal Analysis of Large Spermatocytes.

Journal of visualized experiments : JoVE·2020

Search research articles

Related Experiment Video

Updated: Jul 15, 2026

Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos

Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos

Published on: June 14, 2012

Flies without a spindle checkpoint.

Eulalie Buffin¹, Doruk Emre, Roger E Karess

¹CNRS, Centre de Génétique Moléculaire, Ave de la Terrasse, 91198 Gif sur Yvette, France.

Nature Cell Biology

|April 10, 2007

Summary

Mad2-null Drosophila are viable and fertile, with cells dividing correctly due to rapid chromosome attachment, bypassing the need for the spindle-assembly checkpoint (SAC). This suggests SAC robustness may mask other mitotic defects.

Area of Science:

Cell Biology
Genetics
Molecular Biology

Background:

The spindle-assembly checkpoint (SAC) is crucial for preventing aneuploidy by delaying anaphase until chromosomes are correctly attached.
Mad2 is a key component of the SAC in metazoans.

Purpose of the Study:

To investigate the necessity of Mad2 and the SAC for cell division in Drosophila.
To understand the implications of SAC inactivation on mitotic fidelity and organismal viability.

Main Methods:

Generation and analysis of mad2-null Drosophila.
Microscopy to observe chromosome attachment and cell division.
Experimental manipulation of spindle-assembly efficiency.

Main Results:

More Related Videos

Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes

Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes

Published on: September 13, 2022

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast

Published on: September 26, 2025

Related Experiment Videos

Last Updated: Jul 15, 2026

Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos

Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos

Published on: June 14, 2012

Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes

Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes

Published on: September 13, 2022

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast

Published on: September 26, 2025

Mad2-null Drosophila are viable and fertile, with cells exhibiting normal division despite lacking SAC.

Premature cyclin B degradation accelerates the cell cycle, compensating for the absence of SAC.

Reducing spindle-assembly efficiency renders mad2-null cells dependent on SAC.

The SAC's robustness may mask underlying mitotic defects.

Conclusions:

Drosophila mitosis can proceed accurately without a functional SAC due to rapid chromosome attachment.
The viability of mad2-null mutants challenges the universal requirement of SAC in metazoan cell division.
Previous studies on lethal SAC mutations in Drosophila may be confounded by pleiotropic effects.