GO:0007143 female meiotic nuclear division: Oocyte Meiosis, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0007143 female meiotic nuclear division is the biological process by which the oocyte nucleus divides during meiosis in the female germline.
• In mammals, meiotic initiation requires the MEIOSIN-STRA8 transcriptional module, which switches germ cells from mitosis to meiosis.
• Female meiosis is characterized by two highly asymmetric divisions that produce a large egg and small polar bodies, with dynein-dependent spindle positioning and actin dynamics.
• A Piezo-dependent meiotic checkpoint at the oocyte nuclear envelope monitors nuclear envelope remodeling and can trigger oocyte elimination.
• PLK1 regulates multiple meiotic events including spindle assembly, chromosome segregation, and polar body extrusion.
• Single-cell multi-omics has revealed meiotic recombination hotspots and epigenomic regulation specific to female mammals.
Description
Female meiotic nuclear division (GO:0007143) is the specialized cell cycle process by which the nucleus of a female germ cell divides during meiosis, producing haploid gametes. Unlike mitosis, meiosis involves one round of DNA replication followed by two successive nuclear divisions, meiosis I and meiosis II, with homologous chromosome segregation and sister chromatid segregation, respectively. In females, this process is tightly regulated to ensure accurate chromosome segregation and to generate a single large oocyte capable of supporting embryonic development. Defects in female meiotic nuclear division lead to aneuploidy, which is a leading cause of miscarriage and developmental disorders such as Down syndrome. Understanding the molecular mechanisms of this process is therefore critical for reproductive biology and medicine. Recent studies have identified key regulators such as MEIOSIN, which directs the switch from mitosis to meiosis in mammalian germ cells, and have uncovered female-specific mechanisms of meiotic initiation and progression. Moreover, a Piezo-dependent meiotic checkpoint at the oocyte nuclear envelope has been shown to monitor meiotic progression and eliminate defective oocytes. These findings highlight the importance of female meiotic nuclear division in fertility and disease.
female meiotic nuclear division At A Glance
| GO ID | GO:0007143 |
|---|---|
| GO term | female meiotic nuclear division |
| Ontology | biological_process |
| Synonym | female meiosis, female meiotic division |
| Major function | Nuclear division during meiosis in the female germline, producing haploid oocytes |
| Related process | Meiotic cell cycle, oocyte maturation, chromosome segregation |
| Key regulators | MEIOSIN, STRA8, PLK1, Piezo, actin cytoskeleton |
| Associated diseases | Aneuploidy, infertility, miscarriage, Down syndrome |
What Is GO:0007143?
According to the Gene Ontology, female meiotic nuclear division (GO:0007143) is defined as a cell cycle process by which the cell nucleus divides as part of a meiotic cell cycle in the female germline. This process encompasses the two meiotic divisions that occur in oocytes, leading to the formation of haploid female gametes. It is synonymous with female meiosis and female meiotic division.
Why Is female meiotic nuclear division Important in Cell Biology?
Female meiotic nuclear division is essential for sexual reproduction, as it generates haploid oocytes and ensures genomic integrity in the offspring. Errors in this process are a major cause of aneuploidy, which is associated with infertility, miscarriage, and genetic disorders such as Down syndrome. The process is also unique in its asymmetry, producing a large oocyte and small polar bodies, which requires precise regulation of spindle positioning and cytokinesis. Understanding the molecular mechanisms of female meiotic nuclear division can provide insights into reproductive aging, fertility preservation, and the development of contraceptives.
• Ensures production of haploid oocytes for sexual reproduction.
• Prevents aneuploidy, a leading cause of miscarriage and developmental disorders.
• Regulates asymmetric cell division to preserve maternal resources in the egg.
• Involves a specialized meiotic checkpoint at the nuclear envelope that eliminates defective oocytes.
• Is a target for reproductive toxicology and fertility studies.
• Provides insights into reproductive aging and age-related aneuploidy.
• Involves unique cytoskeletal dynamics that differ from mitosis.
• Is regulated by meiosis-specific transcription factors such as MEIOSIN.
• Has implications for understanding the evolution of meiosis in females.
• Offers potential targets for contraception and infertility treatments.
What Happens During female meiotic nuclear division?
Meiotic Initiation and the Mitosis-to-Meiosis Switch
In simple terms: This is the starting point where germ cells stop dividing like normal cells and begin the special division that makes eggs.
In mammals, female meiotic nuclear division begins during fetal development when germ cells enter meiosis. The switch from mitosis to meiosis is directed by the transcription factor MEIOSIN, which activates a suite of meiosis-specific genes including STRA8. MEIOSIN expression is induced by retinoic acid signaling and is essential for meiotic initiation; its knockout leads to failure of meiotic entry and sterility. Female-specific mechanisms of meiotic initiation involve additional regulatory layers, such as the timing of meiotic entry and the influence of germ cell environment.
Meiosis I: Homologous Chromosome Segregation
In simple terms: In the first division, matching chromosomes pair up and then separate, reducing the chromosome number by half.
During meiosis I, homologous chromosomes pair, recombine, and then segregate to opposite poles. This division is reductional, meaning it reduces the chromosome number from diploid to haploid. In female mammals, meiosis I is initiated prenatally and then arrests at prophase I until ovulation. The process involves the formation of the synaptonemal complex, crossover formation, and proper spindle assembly. PLK1 plays multiple roles in meiosis I, including regulation of spindle assembly and chromosome segregation. Actin cytoskeleton dynamics are also crucial for spindle positioning and polar body extrusion.
Meiosis II: Sister Chromatid Segregation
In simple terms: In the second division, the remaining chromosome copies are separated, similar to mitosis, to produce a single set of chromosomes.
Meiosis II resembles mitosis in that sister chromatids are segregated. In oocytes, meiosis II is completed only upon fertilization. This division is equational and results in the formation of a haploid egg and a second polar body. Proper regulation of meiosis II is critical to avoid aneuploidy. PLK1 continues to regulate spindle function and cytokinesis during meiosis II. The process is also influenced by the oocyte's cytoskeleton, particularly actin and microtubules.
Asymmetric Division and Polar Body Extrusion
In simple terms: The egg divides unequally to keep most of the cell's resources for the future embryo, discarding extra chromosomes in small polar bodies.
Female meiotic nuclear division is highly asymmetric, producing one large oocyte and one or two small polar bodies. This asymmetry is achieved through differential positioning of the spindle and localized actin dynamics. The spindle is anchored near the cortex, and polar body extrusion requires actomyosin contractility. Dynein-dependent spindle positioning is essential for this asymmetry. Defects in asymmetric division can lead to retention of polar bodies or aneuploidy.
Meiotic Checkpoints and Quality Control
In simple terms: The oocyte has surveillance systems that detect problems during division and can eliminate faulty cells.
A Piezo-dependent meiotic checkpoint at the oocyte nuclear envelope monitors nuclear envelope remodeling and meiotic progression. This checkpoint can trigger oocyte elimination if defects are detected, ensuring that only high-quality oocytes proceed to ovulation. Additionally, the spindle assembly checkpoint operates during meiosis to prevent chromosome mis-segregation. These checkpoints are critical for maintaining fertility and preventing aneuploidy.
Key Genes Involved in GO:0007143 female meiotic nuclear division
The following genes and proteins are key players in female meiotic nuclear division, as supported by the cited literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MEIOSIN | Transcription factor that directs the switch from mitosis to meiosis | Knockout causes failure of meiotic initiation and sterility |
| STRA8 | Meiosis-specific gene activated by MEIOSIN; promotes meiotic entry | Essential for meiotic initiation; target of MEIOSIN |
| PLK1 | Regulates spindle assembly, chromosome segregation, and polar body extrusion | Multiple roles in meiosis I and II; potential target for contraception |
| Piezo | Mechanosensitive ion channel involved in meiotic checkpoint at nuclear envelope | Mediates oocyte elimination in response to meiotic defects |
| Actin | Cytoskeletal component required for spindle positioning and polar body extrusion | Dynamics regulated during oocyte meiosis |
| Dynein | Motor protein for spindle positioning and asymmetric division | Critical for polar body extrusion |
| Tubulin | Major component of the meiotic spindle | Target of spindle assembly checkpoint |
| Cohesin | Holds sister chromatids together until meiosis II | Defects lead to aneuploidy |
| Separase | Cleaves cohesin to allow chromosome segregation | Regulated during meiosis |
| Securin | Inhibits separase until proper spindle attachment | Regulated by spindle assembly checkpoint |
| Aurora kinase | Regulates chromosome segregation and spindle assembly | Potential target for meiosis research |
| BubR1 | Spindle assembly checkpoint protein | Monitors chromosome attachment |
| Mad2 | Spindle assembly checkpoint protein | Prevents premature segregation |
| Cdk1 | Cyclin-dependent kinase that drives meiotic progression | Central regulator of meiosis |
| Cyclin B | Regulatory subunit of Cdk1 | Controls meiotic resumption and progression |
| MOS | MAPK kinase kinase that regulates meiosis II arrest | Essential for CSF arrest in oocytes |
| Emi2 | Inhibits APC/C to maintain meiosis II arrest | Regulated by MOS pathway |
How Is female meiotic nuclear division Regulated?
Female meiotic nuclear division is regulated at multiple levels. Transcriptionally, MEIOSIN and STRA8 control the onset of meiosis. Post-translationally, PLK1 and CDK1-cyclin B regulate spindle assembly and cell cycle progression. The Piezo-dependent checkpoint at the nuclear envelope monitors meiotic progression and can induce oocyte elimination. Additionally, actin cytoskeleton dynamics are regulated by small GTPases and actin-binding proteins to ensure asymmetric division. Hormonal signals, such as retinoic acid, also influence meiotic initiation.
female meiotic nuclear division and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MEIOSIN | Infertility due to failure of meiotic initiation | Knockout mouse model |
| PLK1 | Aneuploidy and cancer | Point mutation or knockout in oocytes |
| Piezo | Oocyte quality control and elimination | Knockout or knock-in of Piezo in mouse oocytes |
| Cohesin | Premature ovarian insufficiency and aneuploidy | Conditional knockout in oocytes |
| MOS | Oocyte maturation arrest | Knockout mouse model |
Aneuploidy and Reproductive Disorders
Errors in female meiotic nuclear division are a major cause of aneuploidy, leading to miscarriage, infertility, and developmental disorders such as Down syndrome (trisomy 21). The high incidence of aneuploidy in human oocytes, especially with advanced maternal age, underscores the importance of understanding meiotic regulation.
Cancer and Meiotic Gene Misregulation
Some meiotic genes, such as MEIOSIN and STRA8, are normally silenced in somatic cells but can be aberrantly expressed in cancers, potentially contributing to genomic instability. However, direct links between female meiotic nuclear division and cancer remain an active area of research.
Infertility and Ovarian Insufficiency
Defects in meiotic initiation or progression can lead to premature ovarian insufficiency (POI) and infertility. Mouse models with mutations in meiotic genes such as Meiosin exhibit sterility due to failure of meiotic entry.
From female meiotic nuclear division-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does MEIOSIN knockout block meiotic initiation? | MEIOSIN knockout mouse |
| What is the role of PLK1 in meiosis I? | PLK1 point mutation or knockout in oocytes |
| How does Piezo mediate meiotic checkpoint? | Piezo knockout or knock-in mouse |
| What is the effect of actin dynamics on polar body extrusion? | Actin tagged knock-in or overexpression |
| How does STRA8 overexpression affect meiosis? | STRA8 overexpression in germ cells |
| What are the targets of MEIOSIN? | MEIOSIN knockout followed by RNA-seq |
How to Study the female meiotic nuclear division Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Knockout mouse | Gene function in vivo | Meiotic initiation and progression |
| Live imaging | Spindle dynamics and polar body extrusion | Asymmetric division |
| RNA-seq | Transcriptional changes | Meiotic gene expression |
| Single-cell multi-omics | Meiotic hotspots and epigenomic regulation | Female meiosis |
| Pharmacological inhibition | Kinase activity | PLK1 function |
| Immunofluorescence | Protein localization | Spindle and chromosome dynamics |
| CRISPR/Cas9 | Precise gene editing | Point mutations and knock-ins |
| Proteomics | Protein interactions | Meiotic complex assembly |
Genetic Knockout and Knockdown
Knockout mouse models are widely used to study the function of genes in female meiotic nuclear division. For example, Meiosin knockout mice fail to initiate meiosis and are sterile. Conditional knockout using Cre-loxP allows temporal and spatial control of gene deletion in oocytes.
Live Imaging and Cytoskeletal Analysis
Live imaging of oocytes expressing fluorescently tagged proteins (e.g., actin, tubulin) allows visualization of spindle dynamics and polar body extrusion. This method is crucial for understanding asymmetric division and checkpoint control.
Transcriptomics and Single-Cell Omics
RNA-seq and single-cell multi-omics have been used to identify meiotic hotspots and epigenomic regulation in female mammals. These approaches reveal gene expression changes during meiotic initiation and progression.
Pharmacological Inhibition
Small molecule inhibitors, such as PLK1 inhibitors, can be used to dissect the role of specific kinases in meiosis. This approach provides temporal control and can complement genetic studies.
How CRISPR Can Be Used to Study GO:0007143 female meiotic nuclear division
Knockout
CRISPR knockout is used to create loss-of-function models for genes involved in female meiotic nuclear division. For example, Meiosin knockout mice generated by CRISPR demonstrate the essential role of MEIOSIN in meiotic initiation. Knockout of Plk1 in oocytes reveals its multiple roles in spindle assembly and polar body extrusion.
Point Mutation
Point mutations can be introduced to study specific domains or phosphorylation sites. For instance, point mutations in Plk1 can dissect its kinase-dependent and independent functions in meiosis. Similarly, mutations in Piezo can reveal its role in the meiotic checkpoint.
Knock-in
Knock-in of fluorescent tags or reporter genes allows real-time visualization of meiotic proteins. Tagged knock-in of actin or tubulin enables live imaging of spindle dynamics. Knock-in of disease-associated mutations can model human infertility.
Overexpression
Overexpression of meiotic genes can test sufficiency and gain-of-function effects. For example, overexpression of Stra8 or Meiosin can induce meiotic entry in germ cells. Overexpression of constitutively active PLK1 can disrupt meiotic progression.
How EDITGENE Supports female meiotic nuclear division Research
Researchers studying female meiotic nuclear division-related genes often need to determine whether a candidate gene is causally involved in meiotic initiation, progression, or checkpoint control. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for female meiotic nuclear division research.
Frequently Asked Questions About female meiotic nuclear division
What is female meiotic nuclear division?
Female meiotic nuclear division (GO:0007143) is the process by which the nucleus divides during meiosis in the female germline, producing haploid oocytes.
What genes are involved in female meiotic nuclear division?
Key genes include MEIOSIN, STRA8, PLK1, Piezo, and components of the actin cytoskeleton [1,6,2,5].
How does MEIOSIN regulate female meiosis?
MEIOSIN is a transcription factor that directs the switch from mitosis to meiosis by activating meiosis-specific genes such as STRA8.
What is the role of PLK1 in oocyte meiosis?
PLK1 regulates spindle assembly, chromosome segregation, and polar body extrusion during meiosis I and II.
What is the Piezo-dependent meiotic checkpoint?
It is a surveillance mechanism at the oocyte nuclear envelope that monitors meiotic progression and can trigger oocyte elimination.
Why is female meiosis asymmetric?
Asymmetric division ensures that the oocyte retains most of the cytoplasm and resources for the future embryo, while polar bodies discard extra chromosomes.
What causes aneuploidy in female meiosis?
Errors in chromosome segregation, spindle assembly, or checkpoint control can lead to aneuploidy, which increases with maternal age.
How can I study female meiotic nuclear division in the lab?
Common methods include knockout mouse models, live imaging, RNA-seq, and CRISPR/Cas9 editing [1,5,4].
What diseases are associated with defects in female meiotic nuclear division?
Defects are linked to infertility, miscarriage, and Down syndrome due to aneuploidy.
Does EDITGENE provide services for meiosis research?
Yes, EDITGENE offers knockout, point mutation, knock-in, overexpression, CRISPR library screening, and bioinformatics services for meiosis research [1,6,5,4].
Conclusion
Female meiotic nuclear division (GO:0007143) is a fundamental biological process that ensures the production of haploid oocytes and the transmission of genetic material. Its regulation involves a complex interplay of transcription factors, kinases, and cytoskeletal dynamics, with checkpoints ensuring quality control. Defects in this process lead to aneuploidy and reproductive disorders, making it a critical area of research. Advances in CRISPR-based models and multi-omics technologies are poised to uncover new mechanisms and therapeutic targets.
References
- 1. Ishiguro KI et al.. 2020. MEIOSIN Directs the Switch from Mitosis to Meiosis in Mammalian Germ Cells.. Dev Cell 52(4):429-445.e10 PMID: 32032549
- 2. Liu C et al.. 2024. Chemically induced proximity reveals a Piezo-dependent meiotic checkpoint at the oocyte nuclear envelope.. Science 386(6724):eadm7969 PMID: 39571011
- 3. Shimada R et al.. 2024. Female-specific mechanisms of meiotic initiation and progression in mammalian oocyte development.. Genes Cells 29(10):797-807 PMID: 39119753
- 4. Li J et al.. 2025. Multi-omics analysis reveals single-cell meiotic hotspot dynamics and epigenomic regulations in female mammals.. Cell Rep 44(8):116082 PMID: 40737127
- 5. Duan X et al.. 2019. Actin cytoskeleton dynamics in mammalian oocyte meiosis.. Biol Reprod 100(1):15-24 PMID: 30010726
- 6. Kalous J et al.. 2023. Multiple Roles of PLK1 in Mitosis and Meiosis.. Cells 12(1) PMID: 36611980
- 7. Bennett MD. 1977. The time and duration of meiosis.. Philos Trans R Soc Lond B Biol Sci 277(955):201-26 PMID: 16285
- 8. Fellmeth JE et al.. 2022. A Brief History of Drosophila (Female) Meiosis.. Genes (Basel) 13(5) PMID: 35627159
