Related Experiment Video
Updated: Feb 25, 2026
10:52
Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets
Published on: August 13, 2016
10.2K
Cell Division: NuMA Bears the Load in the Spindle.
Helder Maiato1, António J Pereira2
1Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, Porto, Portugal; Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
Current Biology : CB
|August 9, 2017
Summary
The mitotic spindle distributes chromosome loads during cell division. A new study reveals this process is confined and relies on the protein NuMA for proper function.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Mitosis involves the segregation of chromosomes, a process mediated by the mitotic spindle.
- The distribution of mechanical load across the mitotic spindle during chromosome segregation is not well understood.
- Understanding load distribution is crucial for comprehending mitotic fidelity and preventing aneuploidy.
Purpose of the Study:
- To investigate how mechanical load is distributed across the mitotic spindle during mitosis.
- To identify the molecular factors involved in mitotic spindle load distribution.
- To elucidate the role of the protein NuMA in this process.
Main Methods:
- Utilized advanced microscopy techniques to visualize chromosome-spindle interactions.
- Employed biophysical methods to measure forces and load distribution within the spindle.
- Investigated the function of NuMA through genetic and biochemical approaches.
Main Results:
- Demonstrated that load distribution within the mitotic spindle is a confined process.
- Showed that the microtubule-associated protein NuMA is essential for proper load distribution.
- Identified NuMA's role in cross-linking microtubules to maintain spindle integrity under load.
Conclusions:
- Mitotic spindle load distribution is a regulated and spatially restricted event.
- NuMA plays a critical role in managing mechanical forces on the spindle during mitosis.
- These findings provide new insights into the mechanics of cell division and chromosome segregation.
Related Concept Videos
02:50Spindle Assembly
4.4K
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...
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...
4.4K
02:11Forces Acting on Chromosomes
4.0K
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...
Microtubules and motor proteins exert two types of forces on...
4.0K
02:19The Spindle Assembly Checkpoint
3.9K
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...
3.9K
02:27The Mitotic Spindle
8.2K
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...
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures...
8.2K
02:57Attachment of Sister Chromatids
4.1K
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall...
4.1K
01:13Centrioles and Centrosomes
6.6K
Most animal cells comprise a pair of centrioles together called a centrosome. The cell duplicates its centrosome and contains two centrosomes side-by-side, which begin to move apart during the prophase. As the centrosomes migrate to two different sides of the cell, microtubules start extending from each centrosome toward the other end. The mitotic spindle is composed of the centrosomes and their emerging microtubules.
Near the end of the prophase, also called late prophase or...
Near the end of the prophase, also called late prophase or...
6.6K