Related Experiment Video
Updated: Mar 31, 2026
11:49
Author Spotlight: Establishing CENP-E Knockout HeLa Cells – A Novel Approach to Study Kinesin-7 CENP-E Biology and its Inhibitors
Published on: June 23, 2023
1.3K
DNA deletion as a mechanism for developmentally programmed centromere loss
Maoussi Lhuillier-Akakpo1, Frédéric Guérin1, Andrea Frapporti1
1Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, F-75205 France.
Nucleic Acids Research
|October 28, 2015
Summary
Centromere inactivation involves the loss of the centromere-specific histone H3 variant (CenH3) during development in Paramecium. Two proteins, Pgm and Ezl1, are crucial for this programmed loss of centromeric DNA.
Area of Science:
- Cell Biology
- Genetics
- Epigenetics
Background:
- Centromeres are essential for accurate chromosome segregation during cell division.
- The histone H3 variant CenH3 is a hallmark of active centromeres.
- Mechanisms of centromere inactivation are poorly understood.
Purpose of the Study:
- To investigate the molecular mechanisms of centromere inactivation during somatic nucleus formation in Paramecium.
- To identify proteins involved in the programmed loss of centromeric chromatin.
Main Methods:
- Depletion of specific proteins (Pgm, Ezl1) using RNA interference.
- Analysis of CenH3 protein levels and localization.
- Investigation of histone modifications (H3K9me3, H3K27me3).
Main Results:
- Developmental loss of CenH3 protein occurs during somatic nucleus formation in Paramecium.
- Depletion of the transposase Pgm prevents CenH3 loss.
- Depletion of the methyltransferase Ezl1 also prevents CenH3 loss.
- Ezl1 is required for H3K9me3 and H3K27me3 modifications associated with centromere inactivation.
Conclusions:
- Programmed centromere inactivation involves the developmental elimination of CenH3.
- Pgm and Ezl1 are key regulators of this process.
- Centromere inactivation may be driven by the removal of associated DNA sequences.
Related Concept Videos
02:25Centrosome Duplication
5.2K
The primary microtubule organizing center (MTOC) in animal cells is the centrosome. A centrosome has two cylindrical centrioles at its core. Each centriole consists of nine sets of three microtubules held together by proteins. The centrioles are positioned at right angles to each other and surrounded by a shapeless protein cloud called the pericentriolar matrix, or pericentriolar material (PCM).
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
5.2K
02:25Centrosome Duplication
2.9K
2.9K
02:30Histone Variants at the Centromere
5.3K
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3...
5.3K
01:29Nondisjunction
83.5K
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.
83.5K
01:21Nondisjunction
5.8K
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...
5.8K
02:17Separation of Sister Chromatids
4.7K
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...
4.7K