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Updated: Jun 6, 2026
10:52
Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets
Published on: August 13, 2016
Mitotic membrane helps to focus and stabilize the mitotic spindle
Christopher C Poirier1, Yixian Zheng, Pablo A Iglesias
1Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, USA.
Biophysical Journal
|November 18, 2010
Summary
A computational model reveals how a membrane surrounding the mitotic spindle helps organize microtubules (MTs) by focusing their minus ends and resisting motor protein activity.
Area of Science:
- Cell Biology
- Biophysics
- Computational Biology
Background:
- Microtubules (MTs) and motor proteins are crucial for forming the mitotic spindle during cell division.
- A potential role for a membranous spindle matrix in spindle assembly is suggested but mechanistically unclear.
Purpose of the Study:
- To investigate the potential mechanisms by which a mitotic membrane influences spindle morphology.
- To explore the physical interactions between the mitotic membrane, microtubules, and motor proteins.
Main Methods:
- Development of a computational model simulating the mitotic spindle apparatus.
- Analysis of interactions between an elastic membrane, MTs, and plus-end-directed motor proteins (e.g., Eg5).
Main Results:
- The elastic membrane aids in focusing the minus ends of microtubules.
- The membrane provides a resistive force opposing the action of plus-end-directed MT motors.
Conclusions:
- A surrounding membrane can contribute to mitotic spindle organization and morphology.
- The model provides a biophysical mechanism for membrane-assisted spindle assembly.
Related Concept Videos
02:27The 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 bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
02:27The 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 bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
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...
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...
01:42Microtubule Associated Proteins (MAPs)
Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...
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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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...