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Updated: Jul 3, 2026
10:52
Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets
Published on: August 13, 2016
Myosin-10 and actin filaments are essential for mitotic spindle function
Sarah Woolner1, Lori L O'Brien, Christiane Wiese
1Department of Zoology, University of Wisconsin-Madison, Madison, WI 53706, USA. sarah.woolner@manchester.ac.uk
The Journal of Cell Biology
|July 9, 2008
Summary
Actin filaments (F-actin) and myosin-10 (Myo10) are crucial for mitotic spindle anchoring and function during cell division. This study reveals their essential roles in spindle pole integrity and length regulation.
Area of Science:
- Cell Biology
- Molecular Biology
- Cytoskeleton Dynamics
Background:
- Mitotic spindles, essential for chromosome segregation, are traditionally viewed as microtubule-based structures.
- The involvement of actin filaments (F-actin) and actin-based motors like myosins in mitotic spindle function has been a long-standing debate.
- Previous research indicated myosin-10's importance in meiotic spindle assembly.
Purpose of the Study:
- To investigate the roles of F-actin and myosin-10 (Myo10) in the context of mitotic spindles.
- To determine the necessity of these components for spindle organization, anchoring, and cell division progression.
Main Methods:
- Localization studies to identify the presence and distribution of Myo10 and F-actin within mitotic spindles.
- Functional assays to assess the impact of Myo10 and F-actin on spindle properties and cell cycle progression.
- Comparative analysis of F-actin-dependent and independent roles of Myo10.
Main Results:
- Myo10 was found at mitotic spindle poles, essential for proper spindle anchoring, length, and pole integrity.
- F-actin forms dynamic cables associated with mitotic spindles, connecting them to the cell cortex.
- While both F-actin and Myo10 are required for spindle anchoring, Myo10's role in pole integrity is F-actin independent. They exhibit antagonistic effects on spindle length.
Conclusions:
- F-actin and Myo10 are integral components of the mitotic spindle machinery, beyond their known roles in other cellular processes.
- Myo10 plays a critical, multifaceted role in mitotic spindle organization and function, with both F-actin-dependent and independent mechanisms.
- The findings resolve controversies regarding actin's role in mitosis and highlight novel regulatory mechanisms involving F-actin and Myo10 in spindle dynamics.
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...
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01:18Role of Myosin in Cell Migration
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Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
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