GO:0045141 meiotic telomere clustering: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0045141 (meiotic telomere clustering) describes the early meiotic prophase process in which chromosome ends gather into a bouquet at the inner nuclear envelope near the spindle pole body.
• Bouquet formation precedes synapsis and is required for normal progression through meiosis.
• The process is regulated by DNA damage response proteins such as H2AX and ATM, which are required for correct telomere clustering.
• Actin is required for bouquet formation, while cohesin is required for its resolution.
• The fission yeast protein Taz1 is essential for meiotic telomere clustering and recombination.
• Defects in meiotic telomere clustering are linked to aberrant recombination and meiotic arrest, with implications for infertility and aneuploidy.
Description
Meiotic telomere clustering, formally annotated as GO:0045141, is a conserved cell cycle process in early meiotic prophase in which the dynamic reorganization of telomeres gathers meiotic chromosome ends into a bouquet arrangement at the inner surface of the nuclear envelope proximal to the spindle pole body. This bouquet configuration is observed across diverse eukaryotes, including mammals, plants, and fungi, and it precedes synapsis. Researchers study this process because it is tightly linked to homologous chromosome pairing, recombination, and the fidelity of meiotic chromosome segregation. Disruption of telomere clustering leads to aberrant recombination and meiotic defects, making it relevant to fertility, aneuploidy, and genome stability. The process is not merely a structural curiosity; it is an active, regulated step that depends on DNA damage response factors, cytoskeletal elements, and cohesin. Understanding meiotic telomere clustering therefore provides insight into the mechanistic basis of meiosis and its associated pathologies.
meiotic telomere clustering At A Glance
| GO ID | GO:0045141 |
|---|---|
| GO term | meiotic telomere clustering |
| Ontology | biological_process |
| Synonym | bouquet biosynthesis; bouquet formation |
| Major function | Gathering meiotic chromosome ends into a bouquet at the nuclear envelope to facilitate pairing and progression through meiosis |
| Precedes | Synapsis |
| Key regulators | H2AX, ATM, actin, cohesin, Taz1 |
| Conservation | Observed in mammals, plants, fission yeast, and zebrafish |
What Is GO:0045141?
Meiotic telomere clustering (GO:0045141) is the cell cycle process in which telomeres undergo dynamic reorganization during early meiotic prophase, causing meiotic chromosome ends to gather in a bouquet arrangement at the inner surface of the nuclear envelope near the spindle pole body. This process plays an important role in progression through meiosis and precedes synapsis.
Why Is meiotic telomere clustering Important in Cell Biology?
Meiotic telomere clustering is important because it is a prerequisite for efficient homologous chromosome pairing and recombination, and defects in this process lead to meiotic arrest, aberrant recombination, and aneuploidy. The bouquet stage is conserved across eukaryotes, indicating a fundamental role in meiosis. Because meiosis is central to sexual reproduction and genome stability, understanding telomere clustering has direct implications for infertility, developmental disorders, and cancer biology.
• Required for normal progression through meiosis and precedes synapsis.
• Facilitates homologous chromosome pairing and recombination.
• Defects cause aberrant telomere clustering and meiotic prophase abnormalities.
• H2AX is required for meiotic telomere clustering.
• ATM inactivation results in aberrant telomere clustering during meiotic prophase.
• Actin is required for bouquet formation, and cohesin is required for its resolution.
• Taz1 is required for meiotic telomere clustering and recombination in fission yeast.
• Conserved in plants, where nucleolus-associated telomere clustering precedes synapsis.
• Relevant to infertility and aneuploidy due to meiotic defects.
• Provides a model for studying nuclear envelope dynamics and chromosome positioning.
What Happens During meiotic telomere clustering?
Initiation and telomere attachment to the nuclear envelope
In simple terms: Telomeres first attach to the inner nuclear envelope near the spindle pole body.
During early meiotic prophase, telomeres dynamically reorganize and attach to the inner surface of the nuclear envelope proximal to the spindle pole body, initiating the bouquet arrangement. This attachment is a prerequisite for subsequent clustering and is conserved across eukaryotes.
Bouquet formation and chromosome end gathering
In simple terms: Chromosome ends gather together into a bouquet shape.
Meiotic chromosome ends are gathered into a bouquet arrangement at the nuclear envelope, a process that requires actin for its formation. This clustering is a distinct step that can be uncoupled from other polarization events in the bouquet-stage cell.
Regulation by DNA damage response factors
In simple terms: DNA damage response proteins help control telomere clustering.
H2AX regulates meiotic telomere clustering, and its loss leads to defects in this process. ATM inactivation results in aberrant telomere clustering during meiotic prophase, indicating that ATM is required for correct clustering.
Resolution and transition to synapsis
In simple terms: The bouquet is resolved, allowing synapsis to proceed.
Cohesin is required for the resolution of meiotic telomere clustering, and this resolution precedes synapsis. The bouquet stage is transient, and its proper resolution is necessary for progression through meiosis.
Conservation across species
In simple terms: Similar clustering happens in many different organisms.
Nucleolus-associated telomere clustering and pairing precede meiotic chromosome synapsis in Arabidopsis thaliana. In fission yeast, Taz1 is required for meiotic telomere clustering and recombination. Meiotic chromosome dynamics including telomere clustering have also been described in zebrafish.
Key Genes Involved in GO:0045141 meiotic telomere clustering
The following genes and proteins have been experimentally implicated in meiotic telomere clustering or its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| H2AX | Regulates meiotic telomere clustering | Required for correct clustering; loss causes defects |
| ATM | Required for correct telomere clustering | Inactivation results in aberrant clustering |
| Actin | Required for bouquet formation | Essential for formation of the bouquet |
| Cohesin | Required for resolution of telomere clustering | Needed to resolve the bouquet before synapsis |
| Taz1 | Required for meiotic telomere clustering and recombination | Fission yeast protein essential for clustering and recombination |
| Telomere-associated proteins | Mediate telomere attachment to nuclear envelope | General role in bouquet formation |
| Nuclear envelope proteins | Anchor telomeres at inner nuclear surface | Facilitate bouquet arrangement |
| Spindle pole body components | Define proximal region for clustering | Bouquet forms near spindle pole body |
| Synaptonemal complex proteins | Function downstream of clustering | Synapsis follows clustering |
| Recombination machinery | Acts after clustering | Clustering facilitates recombination |
| Cytoskeletal regulators | Modulate actin-dependent formation | Actin required for formation |
| Cohesin complex subunits | Mediate resolution | Cohesin required for resolution |
| DNA damage response kinases | Regulate clustering | ATM and H2AX involved |
| Plant-specific telomere proteins | Mediate clustering in plants | Nucleolus-associated clustering in Arabidopsis |
| Zebrafish meiotic proteins | Mediate chromosome dynamics | Telomere clustering described in zebrafish |
How Is meiotic telomere clustering Regulated?
Meiotic telomere clustering is regulated by DNA damage response factors, including H2AX and ATM, which are required for correct clustering. Actin is required for the formation of the bouquet, while cohesin is required for its resolution. The process can be uncoupled from other polarization events in the bouquet-stage cell, indicating independent regulatory control.
meiotic telomere clustering and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ATM | Ataxia-telangiectasia; meiotic defects | Atm knockout mouse |
| H2AX | Meiotic defects; genome instability | H2AX knockout mouse |
| Taz1 | Meiotic recombination defects; aneuploidy | Fission yeast taz1 mutant |
| Cohesin subunits | Meiotic arrest; cohesinopathies | Cohesin mutant models |
| Actin regulators | Meiotic bouquet formation defects | Actin mutant models |
Meiotic defects and infertility
Aberrant telomere clustering during meiotic prophase, as seen upon ATM inactivation, can lead to meiotic defects that may contribute to infertility. Proper clustering is required for progression through meiosis and synapsis.
Aneuploidy and genome instability
Defects in meiotic telomere clustering and recombination, such as those observed in Taz1 mutants, can result in aberrant recombination and potentially aneuploidy. Correct clustering is important for faithful chromosome segregation.
Cancer predisposition
ATM inactivation results in aberrant telomere clustering during meiotic prophase. ATM is a well-known cancer predisposition gene, linking meiotic telomere clustering defects to broader genome instability syndromes.
From meiotic telomere clustering-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is H2AX required for telomere clustering? | H2AX knockout mouse |
| Does ATM loss cause aberrant clustering? | Atm knockout mouse |
| Is actin required for bouquet formation? | Actin mutants |
| Is cohesin required for bouquet resolution? | Cohesin mutants |
| Is Taz1 required for clustering and recombination? | Fission yeast taz1 mutant |
| Is clustering conserved in plants? | Arabidopsis thaliana |
How to Study the meiotic telomere clustering Process
| Method | What It Measures | Typical Application |
|---|---|---|
| FISH for telomeres | Telomere clustering and bouquet formation | Meiotic prophase cells |
| Live-cell imaging | Dynamics of telomere movement | Zebrafish and fission yeast meiosis |
| Immunofluorescence | Localization of H2AX, ATM, and other proteins | Meiotic cells |
| Electron microscopy | Ultrastructure of bouquet and nuclear envelope | Meiotic prophase |
| Genetic knockouts | Requirement of genes for clustering | Mouse and yeast models |
| 3D reconstruction | Spatial arrangement of telomeres | Bouquet-stage cells |
| Time-lapse microscopy | Kinetics of clustering and resolution | Meiotic cells |
Fluorescence microscopy of telomere clustering
Visualizing telomeres by fluorescence in situ hybridization or fluorescent protein tagging allows direct observation of bouquet formation and clustering defects in meiotic prophase cells.
Live-cell imaging of meiotic chromosome dynamics
Live-cell imaging in model organisms such as zebrafish and fission yeast enables tracking of telomere movement and clustering over time.
Genetic knockout and mutant analysis
Knockout or mutant models for H2AX, ATM, actin, cohesin, and Taz1 are used to test requirement for clustering and downstream effects on recombination.
Electron microscopy and 3D reconstruction
Electron microscopy and three-dimensional reconstruction can reveal the ultrastructure of the bouquet and its association with the nuclear envelope and spindle pole body.
How CRISPR Can Be Used to Study GO:0045141 meiotic telomere clustering
Knockout
CRISPR knockout of H2AX, ATM, actin regulators, cohesin subunits, or Taz1 can be used to test their requirement for meiotic telomere clustering and downstream meiosis.
Point Mutation
Point mutations in genes such as ATM or H2AX can be introduced to dissect specific domains required for telomere clustering without fully ablating protein function.
Knock-in
Knock-in of fluorescent tags at endogenous loci allows live-cell imaging of telomere clustering and associated proteins.
Overexpression
Overexpression of actin or cohesin regulators can be used to test whether excess protein disrupts the timing or resolution of telomere clustering.
How EDITGENE Supports meiotic telomere clustering Research
Researchers studying meiotic telomere clustering-related genes often need to determine whether a candidate gene is causally involved in bouquet formation, resolution, or downstream recombination. EDITGENE provides CRISPR-based cell models and screening services to enable such functional studies.
Contact EDITGENE today to design your custom CRISPR model for meiotic telomere clustering research.
Frequently Asked Questions About meiotic telomere clustering
What is meiotic telomere clustering?
Meiotic telomere clustering (GO:0045141) is the process in early meiotic prophase in which telomeres gather into a bouquet at the inner nuclear envelope near the spindle pole body, preceding synapsis.
What genes are involved in meiotic telomere clustering?
Genes implicated include H2AX, ATM, actin, cohesin, and Taz1.
Why is meiotic telomere clustering important?
It is required for progression through meiosis and facilitates homologous chromosome pairing and recombination.
What happens if meiotic telomere clustering is defective?
Defects can lead to aberrant recombination, meiotic arrest, and aneuploidy.
Is meiotic telomere clustering conserved across species?
Yes, it is observed in mammals, plants, fission yeast, and zebrafish.
What is the bouquet arrangement?
The bouquet is the clustering of meiotic chromosome ends at the nuclear envelope near the spindle pole body.
Does H2AX regulate meiotic telomere clustering?
Yes, H2AX regulates meiotic telomere clustering.
What role does ATM play in telomere clustering?
ATM inactivation results in aberrant telomere clustering during meiotic prophase.
Is actin required for bouquet formation?
Yes, actin is required for the formation of meiotic telomere clustering.
What is the role of cohesin in telomere clustering?
Cohesin is required for the resolution of meiotic telomere clustering.
Conclusion
Meiotic telomere clustering (GO:0045141) is a conserved and essential step in early meiotic prophase that gathers chromosome ends into a bouquet to facilitate pairing and recombination. Its regulation by H2AX, ATM, actin, cohesin, and Taz1 highlights the interplay between DNA damage response, cytoskeletal dynamics, and chromosome cohesion. Defects in this process are linked to meiotic failure and aneuploidy, making it a key area for reproductive and genome stability research. Continued studies using CRISPR models and advanced imaging will further clarify the molecular mechanisms and disease relevance of meiotic telomere clustering.
References
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- 2. Pandita TK et al.. 1999. Atm inactivation results in aberrant telomere clustering during meiotic prophase.. Mol Cell Biol 19(7):5096-105 PMID: 10373558
- 3. Armstrong SJ et al.. 2001. Nucleolus-associated telomere clustering and pairing precede meiotic chromosome synapsis in Arabidopsis thaliana.. J Cell Sci 114(Pt 23):4207-17 PMID: 11739653
- 4. Trelles-Sticken E et al.. 2005. Meiotic telomere clustering requires actin for its formation and cohesin for its resolution.. J Cell Biol 170(2):213-23 PMID: 16027219
- 5. Scherthan H. 2007. Telomere attachment and clustering during meiosis.. Cell Mol Life Sci 64(2):117-24 PMID: 17219025
- 6. Cowan CR et al.. 2002. Reorganization and polarization of the meiotic bouquet-stage cell can be uncoupled from telomere clustering.. J Cell Sci 115(Pt 19):3757-66 PMID: 12235286
- 7. Cooper JP et al.. 1998. Fission yeast Taz1 protein is required for meiotic telomere clustering and recombination.. Nature 392(6678):828-31 PMID: 9572143
- 8. Imai Y et al.. 2021. Meiotic Chromosome Dynamics in Zebrafish.. Front Cell Dev Biol 9:757445 PMID: 34692709
