GO:0007057 spindle assembly involved in female meiosis I: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0007057 describes the aggregation, arrangement and bonding of spindle components specifically during meiosis I in female meiotic cells.
• The process is best characterized in Drosophila melanogaster oocytes, where the anastral meiosis I spindle assembles via a defined pathway.
• In mammals, spindle assembly during oocyte meiosis I requires proteins such as ZFHX3, FASCIN, CCDC41, and STAT3 signaling.
• Errors in female meiosis I spindle assembly are a major source of aneuploidy, and the spindle assembly checkpoint is less stringent in females than males.
• Environmental exposures such as bisphenol A (BPA) can disrupt meiosis I spindle assembly in oogonia.
• DNA damage responses in oocytes intersect with meiotic spindle assembly and can influence oocyte quality and survival.
Description
Spindle assembly involved in female meiosis I (GO:0007057) is the biological process by which a set of components aggregates, arranges, and bonds together to form the spindle during meiosis I of a female meiotic cell cycle. This process is essential for accurate chromosome segregation and for the production of haploid eggs. The term is defined in the Gene Ontology with an example from Drosophila melanogaster, where the anastral oocyte meiosis I spindle assembles through a well-characterized pathway. In females, meiosis I is particularly error-prone, and defects in spindle assembly contribute to aneuploidy, which is a leading cause of miscarriage and developmental disorders. Understanding the molecular players and regulatory mechanisms of this process is therefore critical for reproductive biology and medicine.
spindle assembly involved in female meiosis I At A Glance
| GO ID | GO:0007057 |
|---|---|
| GO term | spindle assembly involved in female meiosis I |
| Ontology | biological_process |
| Synonym | female meiosis I spindle assembly |
| Definition | The aggregation, arrangement and bonding together of a set of components to form the spindle during meiosis I of a meiotic cell cycle in females. An example of this is found in Drosophila melanogaster. |
| Major function | Formation of the meiosis I spindle in female germ cells, enabling chromosome segregation and polar body extrusion. |
| Example organism | Drosophila melanogaster |
| Related process | Meiotic spindle assembly checkpoint, oocyte maturation, aneuploidy. |
What Is GO:0007057?
GO:0007057 is a biological process term defined as the aggregation, arrangement and bonding together of a set of components to form the spindle during meiosis I of a meiotic cell cycle in females. It encompasses the dynamic assembly of microtubules, motor proteins, and associated factors that build the meiosis I spindle, often in the absence of canonical centrosomes (anastral) in oocytes. The term is distinct from mitotic spindle assembly and from meiosis II spindle assembly, as it is specific to the first meiotic division in female germ cells.
Why Is spindle assembly involved in female meiosis I Important in Cell Biology?
Spindle assembly during female meiosis I is a cornerstone of reproductive success. Errors in this process lead to aneuploid eggs, which are a major cause of infertility, miscarriage, and congenital disorders such as Down syndrome. The process is mechanistically distinct from mitosis and male meiosis, making it a unique target for understanding female-specific meiotic regulation. Moreover, environmental factors like BPA can disrupt this process, highlighting its sensitivity to external insults. Research into GO:0007057 therefore has broad implications for reproductive toxicology, developmental biology, and clinical genetics.
• Ensures accurate chromosome segregation during the first meiotic division in females.
• Prevents aneuploidy, a leading cause of miscarriage and developmental disorders.
• Is a female-specific process with unique regulatory features compared to male meiosis.
• Serves as a target for environmental toxicants such as BPA that disrupt oogonial meiosis.
• Involves specialized proteins like ZFHX3, FASCIN, and CCDC41 that are essential for spindle function.
• Is linked to DNA damage response pathways that monitor oocyte quality.
• Provides insights into the evolution of anastral spindle assembly, as exemplified in Drosophila.
• Has implications for assisted reproductive technologies and fertility preservation.
• Can be studied using CRISPR-based models to dissect gene function in oocyte meiosis.
• Contributes to our understanding of cell cycle checkpoints and their stringency in oocytes.
What Happens During spindle assembly involved in female meiosis I?
Initiation and Microtubule Nucleation
In simple terms: The oocyte starts building the spindle by making and organizing microtubules, the tiny tubes that will pull chromosomes apart.
In female meiosis I, spindle assembly begins with microtubule nucleation and organization around the chromosomes, often in the absence of centrosomes. In Drosophila oocytes, the anastral spindle assembles through a pathway that involves the accumulation of microtubules near the chromosomes and their subsequent rearrangement into a bipolar structure. This initial phase is critical for establishing the spindle axis and ensuring proper chromosome capture.
Chromosome Capture and Alignment
In simple terms: The spindle fibers attach to chromosomes and line them up in the middle, ready to be separated.
Following nucleation, microtubules capture chromosomes and align them at the metaphase plate. This step requires the coordinated action of motor proteins and kinetochore components. In mouse oocytes, proteins such as ZFHX3 are required for proper spindle assembly and chromosome segregation during meiosis I, and their depletion leads to spindle defects and misaligned chromosomes. Similarly, FASCIN regulates actin assembly for spindle movement and polar body extrusion, highlighting the interplay between actin and microtubule networks.
Spindle Bipolarity and Stability
In simple terms: The spindle must form two poles and remain stable to pull chromosomes evenly.
The establishment of spindle bipolarity involves the focusing of microtubule minus ends into poles. In mouse oocytes, dynamic changes in pStat3 are involved in meiotic spindle assembly, suggesting that signaling pathways regulate spindle stability. Additionally, CCDC41 drives oocyte meiotic progression by promoting Rab11a/Rab7-positive vesicle fusion with target membranes, which may contribute to spindle membrane dynamics. Defects in these processes can lead to multipolar spindles and chromosome missegregation.
Spindle Assembly Checkpoint and Anaphase Onset
In simple terms: A safety checkpoint ensures all chromosomes are attached before the cell divides.
The spindle assembly checkpoint (SAC) monitors kinetochore-microtubule attachments and delays anaphase until all chromosomes are properly bi-oriented. In female meiosis I, the SAC is less stringent than in males, contributing to the higher rate of aneuploidy in females. Once the checkpoint is satisfied, anaphase I proceeds, and the spindle facilitates chromosome segregation and polar body extrusion. DNA damage responses in oocytes can also influence this checkpoint and overall meiotic progression.
Key Genes Involved in GO:0007057 spindle assembly involved in female meiosis I
The following genes and proteins have been experimentally implicated in spindle assembly during female meiosis I, based on published studies in model organisms and mammalian oocytes.
| Gene | Major Role | Research Relevance |
|---|---|---|
| ZFHX3 | Required for proper spindle assembly and chromosome segregation during oocyte meiosis I in mice | Knockout leads to spindle defects and aneuploidy; potential model for female infertility |
| FASCIN | Regulates actin assembly for spindle movement and polar body extrusion in mouse oocyte meiosis | Knockdown impairs spindle positioning; links actin dynamics to meiosis I |
| CCDC41 | Drives oocyte meiotic progression by promoting Rab11a/Rab7-positive vesicle fusion | Knockdown delays meiotic progression; potential role in spindle membrane trafficking |
| STAT3 | Dynamic changes in pStat3 are involved in meiotic spindle assembly in mouse oocytes | Signaling pathway that may regulate spindle stability; target for pharmacological modulation |
| BPA (exposure) | Disrupts meiosis I in oogonia by affecting cell cycle regulation, meiosis initiation and spindle assembly | Toxicological model for environmental impacts on female meiosis |
| SAC proteins (e.g., Mad2, BubR1) | Monitor kinetochore-microtubule attachments; less stringent in female meiosis I | Explains higher aneuploidy in females; targets for understanding checkpoint control |
| DNA damage response proteins (e.g., ATM, H2AX) | Respond to DNA damage in oocytes and influence meiotic progression | Links DNA repair to spindle assembly; potential models for oocyte quality |
| Drosophila spindle assembly factors (e.g., Msps, D-TACC) | Mediate anastral spindle assembly in Drosophila oocytes | Genetic models for dissecting the assembly pathway |
| Microtubule motors (e.g., dynein, kinesins) | Generate forces for spindle assembly and chromosome movement | Functional studies via RNAi or CRISPR in oocytes |
| Actin regulators (e.g., RhoA, Formin) | Control actin assembly for spindle positioning and polar body extrusion | Implicated in spindle movement; potential targets for fertility studies |
| Rab11a/Rab7 | Vesicle trafficking proteins that fuse with target membranes during meiotic progression | Regulate membrane dynamics for spindle function; knockdown impairs meiosis |
| pStat3 | Phosphorylated form of STAT3 involved in meiotic spindle assembly | Dynamic changes correlate with spindle assembly; potential biomarker |
| ZFHX3 (human ortholog) | Transcription factor with roles in cell cycle and development | May have conserved functions in human oocyte meiosis; requires further study |
| FASCIN (human ortholog) | Actin-bundling protein involved in cell motility and adhesion | Potential role in human oocyte spindle assembly; not yet fully characterized |
| CCDC41 (human ortholog) | Coiled-coil domain-containing protein involved in vesicle trafficking | Candidate gene for human oocyte maturation defects |
| BubR1 | Spindle assembly checkpoint kinase | Mutations linked to aneuploidy; model for checkpoint dysfunction |
| Mad2 | Spindle assembly checkpoint protein | Key regulator of anaphase onset; studied in oocyte meiosis |
| ATM | DNA damage response kinase | Coordinates DNA repair with meiotic progression; knockout models show oocyte defects |
How Is spindle assembly involved in female meiosis I Regulated?
Spindle assembly during female meiosis I is regulated by multiple signaling pathways and checkpoints. The spindle assembly checkpoint (SAC) monitors kinetochore-microtubule attachments and is less stringent in females, contributing to aneuploidy. Dynamic changes in pStat3 are involved in meiotic spindle assembly in mouse oocytes, suggesting that cytokine signaling can modulate spindle dynamics. Additionally, DNA damage responses in oocytes can influence meiotic progression and spindle assembly, with proteins such as ATM playing a role. Environmental factors like BPA can disrupt meiosis I by affecting cell cycle regulation, meiosis initiation, and spindle assembly pathways. These regulatory layers ensure the fidelity of chromosome segregation but also render the process vulnerable to errors.
spindle assembly involved in female meiosis I and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ZFHX3 | Female infertility, aneuploidy | Knockout mouse oocyte model |
| FASCIN | Oocyte maturation defects, polar body extrusion failure | Knockdown in mouse oocytes |
| CCDC41 | Meiotic progression delay, potential oocyte maturation arrest | Knockdown in mouse oocytes |
| BubR1/Mad2 | Aneuploidy, cancer predisposition | Knockout or point mutation in mouse models |
| ATM | Oocyte depletion, infertility | Knockout mouse models |
Aneuploidy and Reproductive Disorders
Errors in female meiosis I spindle assembly are a primary cause of aneuploidy, leading to miscarriage, infertility, and developmental disorders such as Down syndrome. The reduced stringency of the spindle assembly checkpoint in females compared to males contributes to the higher incidence of aneuploid eggs. Understanding the molecular mechanisms of spindle assembly, including the roles of ZFHX3 and FASCIN, may provide targets for diagnosing or treating reproductive disorders.
Environmental Toxicant-Induced Meiotic Defects
Exposure to bisphenol A (BPA) disrupts meiosis I in oogonia by acting on pathways including cell cycle regulation, meiosis initiation, and spindle assembly. This highlights the sensitivity of female meiosis I to environmental chemicals and suggests that spindle assembly genes may mediate toxicant effects. Research into GO:0007057 can inform risk assessment and protective strategies.
Oocyte Quality and DNA Damage Response
DNA damage responses in mammalian oocytes are closely linked to meiotic progression and spindle assembly. Defects in DNA repair pathways can lead to oocyte apoptosis or impaired spindle formation, affecting fertility. Studying the interplay between DNA damage response and spindle assembly may reveal new biomarkers for oocyte quality.
From spindle assembly involved in female meiosis I-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate spindle assembly in female meiosis I? | Knockout (KO) mouse oocytes or Drosophila mutants |
| What is the effect of a specific point mutation in a spindle gene? | Point-mutation knock-in via CRISPR in oocytes |
| How does a tagged protein localize during meiosis I? | Tagged knock-in (e.g., GFP) in mouse oocytes |
| Does overexpression of gene Y cause spindle defects? | Overexpression in oocytes via mRNA injection or transgenic models |
| What is the role of a gene in aneuploidy? | Knockout or knockdown followed by chromosome spread analysis |
| How does BPA exposure affect spindle assembly? | In vitro oogonia culture with BPA treatment |
How to Study the spindle assembly involved in female meiosis I Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Spindle dynamics and chromosome movements | Visualizing anastral spindle assembly in Drosophila oocytes |
| Immunofluorescence | Spindle morphology, protein localization | Assessing ZFHX3 or FASCIN knockdown phenotypes |
| CRISPR knockout | Gene function in spindle assembly | Generating Zfhx3 knockout mouse models |
| RNAi knockdown | Acute loss-of-function effects | Studying CCDC41 in oocyte meiosis |
| Phosphoproteomics | Signaling changes during meiosis | Detecting pStat3 dynamics |
| Chromosome spread analysis | Aneuploidy and chromosome segregation errors | Evaluating SAC stringency in female meiosis |
| BPA exposure assays | Toxicant effects on spindle assembly | Oogonia culture models |
| DNA damage response assays | DNA repair and meiotic progression | Studying ATM in oocytes |
Live-Cell Imaging of Spindle Dynamics
Live-cell imaging using fluorescently labeled tubulin and chromosomes allows real-time visualization of spindle assembly in oocytes. This method has been used to characterize the anastral spindle assembly pathway in Drosophila oocytes and to assess spindle defects in mouse oocytes lacking ZFHX3. It provides spatial and temporal resolution of microtubule dynamics and chromosome movements.
Immunofluorescence and Confocal Microscopy
Immunofluorescence staining of spindle components (e.g., alpha-tubulin, pericentrin) and kinetochore proteins is widely used to evaluate spindle morphology and chromosome alignment. Studies on FASCIN and CCDC41 have employed this approach to link protein function to spindle movement and polar body extrusion. This method is quantitative and can be combined with high-content imaging.
Genetic Knockout and Knockdown Models
CRISPR/Cas9-mediated knockout or RNAi-mediated knockdown in oocytes or model organisms is essential for determining gene function. For example, Zfhx3 knockout mice exhibit spindle assembly defects, and Ccdc41 knockdown impairs meiotic progression. These models allow causal inference and are complemented by rescue experiments.
Proteomics and Phosphoproteomics
Mass spectrometry-based proteomics can identify proteins associated with the meiosis I spindle and their post-translational modifications. Dynamic changes in pStat3 during meiotic spindle assembly were revealed by phospho-specific antibodies and imaging. Proteomic profiling of oocytes at different meiotic stages can uncover novel regulators of GO:0007057.
How CRISPR Can Be Used to Study GO:0007057 spindle assembly involved in female meiosis I
Knockout
CRISPR/Cas9 knockout of genes such as Zfhx3 in mouse oocytes has demonstrated their essential role in spindle assembly during female meiosis I, leading to spindle defects and chromosome missegregation. Knockout models are powerful for establishing causality and for studying the consequences of gene loss on oocyte maturation and fertility.
Point Mutation
Point mutations can be introduced via CRISPR to model specific amino acid changes in spindle-associated proteins, mimicking human variants or disrupting phosphorylation sites. This approach allows fine-tuning of protein function without complete loss, as exemplified by studies on SAC proteins like BubR1.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) or epitope tags into endogenous loci enables real-time tracking of spindle proteins in oocytes. This has been used to study the dynamic localization of pStat3 during meiotic spindle assembly. Knock-in models preserve endogenous regulation and are valuable for live imaging.
Overexpression
Overexpression of spindle-related genes, such as FASCIN, can be achieved via mRNA injection or transgenic constructs to test gain-of-function effects on spindle movement and polar body extrusion. Overexpression studies complement loss-of-function approaches and can reveal dominant-negative or hyperactive phenotypes.
How EDITGENE Supports spindle assembly involved in female meiosis I Research
Researchers studying spindle assembly involved in female meiosis I-related genes often need to determine whether a candidate gene is causally involved in spindle formation, chromosome segregation, or oocyte maturation. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from knockout and point mutation models to knock-in reporters and overexpression systems, as well as library screening and bioinformatics support.
Contact EDITGENE today to design your custom CRISPR model for spindle assembly involved in female meiosis I research.
Frequently Asked Questions About spindle assembly involved in female meiosis I
What is spindle assembly involved in female meiosis I?
It is the biological process (GO:0007057) by which the spindle forms during the first meiotic division in female germ cells, enabling chromosome segregation.
What genes are involved in spindle assembly involved in female meiosis I?
Key genes include ZFHX3, FASCIN, CCDC41, STAT3, and components of the spindle assembly checkpoint such as BubR1 and Mad2.
Why is female meiosis I spindle assembly important?
It ensures accurate chromosome segregation; errors lead to aneuploidy, miscarriage, and developmental disorders.
How is spindle assembly involved in female meiosis I studied?
Common methods include live-cell imaging, immunofluorescence, CRISPR knockout, RNAi knockdown, and proteomics.
What is the role of ZFHX3 in female meiosis I?
ZFHX3 is required for proper spindle assembly and chromosome segregation during oocyte meiosis I in mice.
How does BPA affect female meiosis I spindle assembly?
BPA disrupts meiosis I in oogonia by acting on pathways including cell cycle regulation, meiosis initiation, and spindle assembly.
What is the spindle assembly checkpoint in female meiosis I?
It is a surveillance mechanism that monitors kinetochore-microtubule attachments; it is less stringent in females, contributing to aneuploidy.
Can CRISPR be used to study spindle assembly in female meiosis I?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools for dissecting gene function in this process.
What diseases are linked to defects in female meiosis I spindle assembly?
Aneuploidy-related conditions such as Down syndrome, infertility, and miscarriage are linked to spindle assembly errors.
What model organisms are used to study female meiosis I spindle assembly?
Drosophila melanogaster and mouse are widely used, with the anastral spindle pathway characterized in Drosophila oocytes.
Conclusion
Spindle assembly involved in female meiosis I (GO:0007057) is a fundamental biological process that ensures accurate chromosome segregation in female germ cells. Its unique features, such as anastral spindle formation and a less stringent spindle assembly checkpoint, make it a critical area of study for understanding aneuploidy and reproductive disorders. Research using CRISPR-based models and advanced imaging continues to uncover the molecular players, including ZFHX3, FASCIN, and CCDC41, that drive this process. These insights hold promise for improving fertility treatments and diagnosing meiotic defects.
References
- 1. Huang C et al.. 2026. Zfhx3 is required for proper spindle assembly and chromosome segregation during oocyte meiosis I in mice.. Front Cell Dev Biol 14:1811072 PMID: 41970960
- 2. Loup B et al.. 2022. BPA disrupts meiosis I in oogonia by acting on pathways including cell cycle regulation, meiosis initiation and spindle assembly.. Reprod Toxicol 111:166-177 PMID: 35667523
- 3. Lane S et al.. 2019. Meiotic spindle assembly checkpoint and aneuploidy in males versus females.. Cell Mol Life Sci 76(6):1135-1150 PMID: 30564841
- 4. Haraguchi S et al.. 2020. Dynamic Changes in pStat3 are Involved in Meiotic Spindle Assembly in Mouse Oocytes.. Int J Mol Sci 21(4) PMID: 32059373
- 5. Sköld HN et al.. 2005. Assembly pathway of the anastral Drosophila oocyte meiosis I spindle.. J Cell Sci 118(Pt 8):1745-55 PMID: 15797926
- 6. Hu LL et al.. 2021. FASCIN regulates actin assembly for spindle movement and polar body extrusion in mouse oocyte meiosis.. J Cell Physiol 236(11):7725-7733 PMID: 34018605
- 7. Tian Y et al.. 2026. CCDC41 Drives Oocyte Meiotic Progression by Promoting Rab11a/Rab7-Positive Vesicle Fusion with Target Membranes.. Adv Sci (Weinh) 13(8):e04665 PMID: 41331237
- 8. Collins JK et al.. 2016. DNA damage responses in mammalian oocytes.. Reproduction 152(1):R15-22 PMID: 27069010
