Related Experiment Video
Updated: Dec 21, 2025
06:39
Live Cell Imaging of Chromosome Segregation During Mitosis
Published on: March 14, 2018
9.7K
Centromere assembly and non-random sister chromatid segregation in stem cells
Ben L Carty1, Elaine M Dunleavy1
1Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway H91 W2TY, Ireland.
Essays in Biochemistry
|May 15, 2020
Summary
Asymmetric cell division relies on unequal distribution of centromere protein A (CENP-A) in Drosophila germline stem cells. This epigenetic asymmetry guides cell fate determination and chromosome segregation.
Area of Science:
- Cell Biology
- Epigenetics
- Developmental Biology
Background:
- Asymmetric cell division (ACD) is crucial for multicellular organism development, producing distinct daughter cells.
- Epigenetic mechanisms, particularly at centromeres, regulate cell fate and chromosome segregation.
- Centromeres, defined by CENP-A, are vital for accurate chromosome distribution during cell division.
Purpose of the Study:
- To review recent evidence for asymmetric sister centromeres in stem cells.
- To explore mechanisms establishing centromere asymmetry.
- To discuss the influence of centromere asymmetry on cell fate.
Main Methods:
- Review of recent scientific literature on asymmetric cell division and centromere biology.
- Discussion of epigenetic mechanisms and histone variants (CENP-A).
- Analysis of chromosome segregation in Drosophila germline stem cells (GSCs).
Main Results:
- CENP-A is asymmetrically distributed between sister chromatids in Drosophila GSCs.
- This asymmetry favors retention of CENP-A in the stem cell lineage.
- Imbalanced centromere strength correlates with asymmetric mitotic spindle assembly.
Conclusions:
- Asymmetric centromere strength is a key feature of stem cell ACD.
- This epigenetic asymmetry plays a role in biased chromosome segregation and cell fate.
- Further research into the mechanisms and consequences of centromere asymmetry is warranted.
Related Concept Videos
02:57Attachment of Sister Chromatids
3.8K
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...
3.8K
02:19The Spindle Assembly Checkpoint
3.6K
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...
3.6K
02:20Cohesins
5.3K
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
5.3K
02:17Separation of Sister Chromatids
4.2K
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...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.2K
02:02Meiosis II
48.8K
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
48.8K
01:57Meiosis II
205.6K
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each...
205.6K