Related Experiment Video

Updated: Sep 25, 2025

Live Cell Imaging of Chromosome Segregation During Mitosis
06:39

Live Cell Imaging of Chromosome Segregation During Mitosis

Published on: March 14, 2018

9.5K

Endomembranes promote chromosome missegregation by ensheathing misaligned chromosomes

Nuria Ferrandiz1, Laura Downie1, Georgina P Starling1

  • 1Centre for Mechanochemical Cell Biology, Warwick Medical School, Coventry, UK.

The Journal of Cell Biology
|April 29, 2022
PubMed

Insights

Misaligned chromosomes outside the mitotic spindle

Area of Science:

  • Cell biology
  • Cancer research
  • Genetics

Background:

  • Chromosome missegregation during mitosis causes aneuploidy and micronucleus formation, linked to cancer.
  • Proper chromosome alignment by the mitotic spindle is crucial for accurate cell division.
  • Endomembranes, primarily endoplasmic reticulum, are densely packed outside the spindle's exclusion zone.

Purpose of the Study:

  • To investigate the fate of misaligned chromosomes located beyond the spindle exclusion zone.
  • To determine the role of endomembranes in chromosome missegregation.
  • To explore therapeutic strategies for preventing aneuploidy.

Main Methods:

  • Live-cell imaging to observe chromosome behavior and endomembrane interactions.
  • Induced organelle relocalization to manipulate endomembrane proximity to chromosomes.
  • Analysis of chromosome missegregation and micronucleus formation frequencies.

Main Results:

  • Misaligned chromosomes outside the exclusion zone become ensheathed in multiple endomembrane layers.
  • Endomembrane ensheathing delays mitosis and increases chromosome missegregation and micronucleus formation.
  • Clearance of endomembranes rescues missegregated chromosomes, reducing aneuploidy risk.

Conclusions:

  • Endomembranes promote the missegregation of misaligned chromosomes outside the spindle exclusion zone.
  • Endomembrane accumulation near chromosomes is a risk factor for aneuploidy.
  • Targeting endomembrane interactions could offer novel cancer therapeutic approaches.

More Related Videos

Preparation of Meiotic Chromosome Spreads from Mouse Oocytes for Assessment of Synapsis and Recombination09:26

Preparation of Meiotic Chromosome Spreads from Mouse Oocytes for Assessment of Synapsis and Recombination

Published on: July 18, 2025

435
Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes10:09

Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes

Published on: September 13, 2022

2.2K

Related Concept Videos

Forces Acting on Chromosomes02:11

Forces 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...
3.4K
Attachment of Sister Chromatids02:57

Attachment of Sister Chromatids

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...
3.5K
Nondisjunction01:29

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
76.6K
Condensins02:15

Condensins

Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
3.7K
The Spindle Assembly Checkpoint02:19

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...
3.3K
Separation of Sister Chromatids02:17

Separation of Sister Chromatids

At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
3.8K