GO:1905325 regulation of meiosis I spindle assembly checkpoint: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1905325 describes any process that modulates the frequency, rate or extent of the meiosis I spindle assembly checkpoint, a surveillance mechanism that delays anaphase I until all chromosomes are properly attached to the spindle.
• The meiosis I spindle assembly checkpoint is mechanistically distinct from mitosis because it must monitor both homologous chromosome biorientation and the unique geometry of the first meiotic division.
• Key regulators include APC/C, CENP-F, DRP1, CENP-E, UBE2S, and mTOR-dependent signaling, which together control checkpoint silencing and chromosome segregation fidelity.
• Dysregulation of this checkpoint is linked to aneuploidy, infertility, and developmental disorders, making it a critical area for reproductive and cancer biology.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models enable causal dissection of checkpoint gene function in oocytes and cell lines.
• EDITGENE provides end-to-end CRISPR services including library screening and bioinformatics to accelerate research on GO:1905325-related genes.
Description
The regulation of meiosis I spindle assembly checkpoint (GO:1905325) encompasses all processes that modulate the frequency, rate or extent of the spindle assembly checkpoint during the first meiotic division. This checkpoint is a surveillance mechanism that delays anaphase I until all homologous chromosomes are properly attached to the spindle apparatus, thereby preventing chromosome missegregation. In mammalian oocytes, the meiosis I spindle assembly checkpoint is particularly important because errors in this process are a leading cause of aneuploidy, miscarriage, and infertility. Understanding how this checkpoint is regulated at the molecular level is therefore essential for reproductive biology and for understanding the origins of chromosomal instability. Recent studies have identified key regulators such as CENP-F, DRP1, CENP-E, and UBE2S that control checkpoint activity and silencing during meiosis I. These findings highlight the complexity of the regulatory network and the need for precise genetic tools to dissect gene function.
regulation of meiosis I spindle assembly checkpoint At A Glance
| GO ID | GO:1905325 |
|---|---|
| GO term | regulation of meiosis I spindle assembly checkpoint |
| Ontology | biological_process |
| Synonym | none |
| Major function | Modulates the meiosis I spindle assembly checkpoint to ensure proper chromosome segregation |
| Related process | Spindle assembly checkpoint, meiosis I, chromosome segregation |
| Key regulators | APC/C, CENP-F, DRP1, CENP-E, UBE2S, mTOR |
| Disease relevance | Aneuploidy, infertility, developmental disorders |
What Is GO:1905325?
GO:1905325 is defined as any process that modulates the frequency, rate or extent of the meiosis I spindle assembly checkpoint. In other words, it includes all molecular events that either activate, maintain, or silence the checkpoint during the first meiotic division, ensuring that chromosome segregation occurs with high fidelity.
Why Is regulation of meiosis I spindle assembly checkpoint Important in Cell Biology?
The regulation of the meiosis I spindle assembly checkpoint is critical for preventing aneuploidy, which is a major cause of miscarriage, congenital disorders, and infertility. Unlike mitosis, meiosis I involves the segregation of homologous chromosomes, requiring a specialized checkpoint that can monitor both attachment and tension. Dysregulation of this checkpoint can lead to premature or delayed anaphase I, resulting in chromosome missegregation. Therefore, understanding the molecular players and regulatory mechanisms is essential for developing diagnostic and therapeutic strategies for reproductive disorders and for understanding the origins of chromosomal instability in cancer.
• Prevents aneuploidy by delaying anaphase I until all chromosomes are properly attached.
• Essential for female fertility and oocyte quality.
• Dysregulation is linked to Down syndrome and other trisomies.
• Involved in the response to spindle poisons and chemotherapeutic agents.
• Provides a model for understanding checkpoint evolution and specialization.
• Key genes are potential targets for reproductive medicine and cancer therapy.
• CRISPR screens can identify novel regulators of this checkpoint.
• Bioinformatics analysis of checkpoint gene networks can reveal disease associations.
What Happens During regulation of meiosis I spindle assembly checkpoint?
Checkpoint activation at kinetochores
In simple terms: The checkpoint senses unattached kinetochores and sends a 'wait' signal.
During early meiosis I, unattached kinetochores recruit checkpoint proteins such as MAD1, MAD2, and BUBR1 to generate a diffusible inhibitor of the anaphase-promoting complex/cyclosome (APC/C). This inhibition prevents premature anaphase I onset. In oocytes, the checkpoint must also monitor the unique geometry of homologous chromosome biorientation.
Checkpoint maintenance and signal amplification
In simple terms: The 'wait' signal is amplified to ensure a robust delay.
The checkpoint signal is amplified through the mitotic checkpoint complex (MCC), which sequesters CDC20 and inhibits APC/C. Recent studies have shown that CENP-F and DRP1 regulate APC/C activity during oocyte meiosis I, influencing checkpoint maintenance. Similarly, CENP-E is required for chromosome alignment and checkpoint function in meiosis I.
Checkpoint silencing and anaphase I onset
In simple terms: Once all chromosomes are attached, the 'wait' signal is turned off.
When all kinetochores achieve proper attachment, the checkpoint is silenced, allowing APC/C activation and anaphase I onset. UBE2S loss causes meiosis I arrest with normal spindle assembly checkpoint dynamics, indicating that checkpoint silencing is a tightly regulated process. mTOR signaling also contributes to asymmetric division and may influence checkpoint silencing.
Spatial regulation of the checkpoint
In simple terms: The checkpoint is organized in specific cellular locations.
Spatial regulation of the spindle assembly checkpoint and APC/C has been studied in Aspergillus nidulans, revealing that checkpoint components localize to kinetochores and spindle poles. In mammalian oocytes, similar spatial organization ensures efficient checkpoint signaling.
Checkpoint reset and meiosis II transition
In simple terms: After anaphase I, the checkpoint is reset for the second division.
Following anaphase I, the checkpoint must be reset to allow meiosis II to proceed. This reset involves the degradation of checkpoint proteins and the re-activation of APC/C. Defects in reset can lead to arrest or aneuploidy.
Key Genes Involved in GO:1905325 regulation of meiosis I spindle assembly checkpoint
The following genes and proteins are key regulators of the meiosis I spindle assembly checkpoint, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| APC/C | E3 ubiquitin ligase that drives anaphase I | Central target of checkpoint inhibition |
| CENP-F | Regulates APC/C activity and DRP1 function | Knockout causes checkpoint defects |
| DRP1 | Mitochondrial fission protein with non-canonical role in APC/C regulation | CENP-F-dependent function in meiosis I |
| CENP-E | Kinesin-7 motor for chromosome alignment and checkpoint | Required for meiosis I progression |
| UBE2S | Ubiquitin-conjugating enzyme | Loss causes meiosis I arrest |
| mTOR | Serine/threonine kinase | Required for asymmetric division |
| MAD1 | Checkpoint protein | Recruits MAD2 to kinetochores |
| MAD2 | Checkpoint protein | Inhibits APC/C |
| BUBR1 | Checkpoint kinase | Monitors kinetochore attachment |
| BUB1 | Checkpoint kinase | Phosphorylates downstream targets |
| CDC20 | APC/C co-activator | Sequestrated by MCC |
| MPS1 | Kinase | Essential for checkpoint activation |
| Aurora B | Chromosomal passenger kinase | Regulates error correction |
| PLK1 | Polo-like kinase | Promotes checkpoint silencing |
| Separase | Protease | Cleaves cohesin at anaphase I |
| Securin | Separase inhibitor | Degraded by APC/C |
| Cyclin B | CDK1 activator | Degraded by APC/C |
How Is regulation of meiosis I spindle assembly checkpoint Regulated?
The meiosis I spindle assembly checkpoint is regulated by multiple signaling pathways. mTOR is required for asymmetric division through small GTPases in mouse oocytes, indirectly influencing checkpoint timing. Spatial regulation of checkpoint components, as shown in Aspergillus nidulans, involves localization to kinetochores and spindle poles. Additionally, CENP-F-dependent DRP1 function regulates APC/C activity, linking mitochondrial dynamics to checkpoint control. UBE2S loss causes meiosis I arrest with normal checkpoint dynamics, suggesting that ubiquitin conjugation is critical for checkpoint silencing.
regulation of meiosis I spindle assembly checkpoint and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CENP-E | Meiosis I arrest, aneuploidy | Knockout mouse oocytes |
| UBE2S | Meiosis I arrest | Knockout mouse oocytes |
| CENP-F | Checkpoint defects | Knockout cell lines |
| DRP1 | Mitochondrial dynamics, checkpoint | Knockout mouse oocytes |
| mTOR | Asymmetric division defects | Knockout mouse oocytes |
Aneuploidy and reproductive disorders
Errors in the regulation of meiosis I spindle assembly checkpoint lead to aneuploidy, a major cause of miscarriage, infertility, and congenital disorders such as Down syndrome. Defects in checkpoint genes like CENP-E and UBE2S result in meiosis I arrest or missegregation.
Cancer and chromosomal instability
Checkpoint dysfunction is a hallmark of chromosomal instability in cancer. While most cancer research focuses on mitosis, meiotic checkpoint regulators may have paralogs or shared components that contribute to tumorigenesis.
Developmental disorders
Mutations in genes regulating the meiosis I checkpoint can cause developmental disorders due to aneuploidy. For example, altered mTOR signaling affects oocyte maturation and may contribute to developmental defects.
From regulation of meiosis I spindle assembly checkpoint-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate checkpoint activation? | Knockout cell line or oocyte |
| Does mutation in gene X affect checkpoint silencing? | Point-mutation knock-in |
| Does gene X interact with APC/C? | Tagged knock-in (e.g., GFP) |
| Does overexpression of gene X cause checkpoint arrest? | Overexpression cell line |
| Which genes are essential for meiosis I checkpoint? | CRISPR library screening |
| What are the transcriptomic changes upon checkpoint activation? | RNA-seq |
How to Study the regulation of meiosis I spindle assembly checkpoint Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Chromosome dynamics and anaphase onset | Oocyte maturation studies |
| RNA-seq | Transcriptional changes | Checkpoint activation |
| Proteomics | Protein interactions and modifications | Checkpoint complex composition |
| CRISPR knockout screening | Gene essentiality | Novel regulator discovery |
| Immunofluorescence | Protein localization | Kinetochore recruitment |
| Western blot | Protein expression and phosphorylation | Checkpoint signaling |
| Flow cytometry | Cell cycle profile | Checkpoint arrest |
Live-cell imaging of chromosome dynamics
Live-cell imaging with fluorescently tagged histones and kinetochore proteins allows real-time monitoring of chromosome alignment and anaphase I onset in oocytes.
RNA-seq and transcriptomics
RNA-seq can reveal gene expression changes associated with checkpoint activation or silencing in oocytes and cell lines.
Proteomics and interactomics
Mass spectrometry-based proteomics can identify protein complexes and post-translational modifications of checkpoint components.
CRISPR library screening
Genome-wide CRISPR knockout screens can identify novel regulators of the meiosis I spindle assembly checkpoint.
How CRISPR Can Be Used to Study GO:1905325 regulation of meiosis I spindle assembly checkpoint
Knockout
CRISPR knockout of candidate genes such as CENP-E or UBE2S in mouse oocytes or cell lines can reveal their requirement for meiosis I checkpoint function.
Point Mutation
Point mutations can be introduced to mimic disease-associated variants or to abrogate specific phosphorylation sites in checkpoint kinases.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) allows real-time visualization of checkpoint proteins at kinetochores.
Overexpression
Overexpression of checkpoint components can cause constitutive checkpoint activation or arrest, helping to dissect regulatory mechanisms.
How EDITGENE Supports regulation of meiosis I spindle assembly checkpoint Research
Researchers studying regulation of meiosis I spindle assembly checkpoint-related genes often need to determine whether a candidate gene is causally involved in checkpoint control, and CRISPR-based models provide the most direct approach.
Contact EDITGENE today to design your custom CRISPR model for regulation of meiosis I spindle assembly checkpoint research.
Frequently Asked Questions About regulation of meiosis I spindle assembly checkpoint
What is GO:1905325?
GO:1905325 is a Gene Ontology term for regulation of meiosis I spindle assembly checkpoint, describing any process that modulates the frequency, rate or extent of the checkpoint during the first meiotic division.
What genes are involved in regulation of meiosis I spindle assembly checkpoint?
Key genes include APC/C, CENP-F, DRP1, CENP-E, UBE2S, and mTOR, among others.
Why is the meiosis I spindle assembly checkpoint important?
It prevents aneuploidy by delaying anaphase I until all chromosomes are properly attached, and its dysfunction causes infertility and developmental disorders.
How is the meiosis I spindle assembly checkpoint regulated?
It is regulated by checkpoint proteins like MAD2 and BUBR1, as well as by APC/C, CENP-F, DRP1, and mTOR signaling.
What diseases are associated with defects in this checkpoint?
Aneuploidy, miscarriage, Down syndrome, and certain cancers are linked to checkpoint defects.
What model systems are used to study this checkpoint?
Mouse oocytes, cell lines, and Aspergillus nidulans are common models.
How can CRISPR help study regulation of meiosis I spindle assembly checkpoint?
CRISPR knockout, point mutation, knock-in, and overexpression models allow causal testing of gene function in checkpoint control.
What is the role of CENP-E in meiosis I?
CENP-E mediates chromosome alignment and spindle assembly checkpoint in meiosis I.
What is the role of UBE2S in meiosis I?
Loss of UBE2S causes meiosis I arrest with normal spindle assembly checkpoint dynamics.
How does mTOR regulate meiosis I?
mTOR is required for asymmetric division through small GTPases in mouse oocytes.
Conclusion
The regulation of meiosis I spindle assembly checkpoint (GO:1905325) is a critical biological process that ensures faithful chromosome segregation during the first meiotic division. Dysregulation of this checkpoint leads to aneuploidy and reproductive disorders, making it a key area of research. Recent studies have identified essential regulators such as CENP-F, DRP1, CENP-E, and UBE2S, providing new insights into the molecular mechanisms. CRISPR-based models and bioinformatics tools are indispensable for further dissecting this process and developing therapeutic strategies.
References
- 1. Zhou CJ et al.. 2022. CENP-F-dependent DRP1 function regulates APC/C activity during oocyte meiosis I.. Nat Commun 13(1):7732 PMID: 36513638
- 2. Sun SM et al.. 2024. Loss of UBE2S causes meiosis I arrest with normal spindle assembly checkpoint dynamics in mouse oocytes.. Development 151(6) PMID: 38546043
- 3. Polanski Z. 2013. Spindle assembly checkpoint regulation of chromosome segregation in mammalian oocytes.. Reprod Fertil Dev 25(3):472-83 PMID: 22951024
- 4. Zhang JL et al.. 2024. Kinesin-7 CENP-E mediates chromosome alignment and spindle assembly checkpoint in meiosis I.. Chromosoma 133(2):149-168 PMID: 38456964
- 5. Sun SC et al.. 2012. Spindle assembly checkpoint and its regulators in meiosis.. Hum Reprod Update 18(1):60-72 PMID: 22086113
- 6. Lee SE et al.. 2012. mTOR is required for asymmetric division through small GTPases in mouse oocytes.. Mol Reprod Dev 79(5):356-66 PMID: 22407942
- 7. Lara-Gonzalez P et al.. 2012. The spindle assembly checkpoint.. Curr Biol 22(22):R966-80 PMID: 23174302
- 8. Edgerton H et al.. 2015. Spatial regulation of the spindle assembly checkpoint and anaphase-promoting complex in Aspergillus nidulans.. Mol Microbiol 95(3):442-57 PMID: 25417844
