GO:0030893 meiotic cohesin complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0030893 (meiotic cohesin complex) is a cohesin complex that mediates sister chromatid cohesion during meiosis and has a subunit composition distinct from the mitotic cohesin complex.
• Meiotic cohesin rings are loaded at meiotic entry and are remodeled into specialized complexes that hold homologs together and later release arm cohesion in two steps.
• The complex includes meiosis-specific subunits such as REC8, STAG3, RAD21L and SMC1B in mammals, whereas mitotic cells use RAD21 and STAG1/2.
• Meiotic cohesin is essential for synaptonemal complex assembly, crossover formation, centromere pairing and accurate chromosome segregation.
• Cohesin ring gates and accessory proteins such as Pds5A regulate meiotic spindle assembly and chromosome dynamics.
• Dysfunction of meiotic cohesin subunits is linked to aneuploidy, infertility and cancer, making these genes important experimental targets.
Description
The meiotic cohesin complex (GO:0030893) is a specialized cohesin complex that mediates sister chromatid cohesion during meiosis and has a subunit composition distinct from that of the mitotic cohesin complex. Cohesin is a ring-shaped ATPase complex that topologically entraps DNA, and in meiosis it must perform additional tasks: holding homologous chromosomes together, supporting synaptonemal complex assembly, and enabling stepwise loss of cohesion during the two meiotic divisions. Because meiosis produces haploid gametes, errors in meiotic cohesin function lead to aneuploidy, which is a major cause of miscarriage and developmental disorders. Researchers study GO:0030893 to understand how chromosome segregation is rewired for meiosis, how meiosis-specific subunits such as REC8 and STAG3 alter ring behavior, and how mutations in these subunits contribute to infertility and cancer. The complex is also a model for how a conserved molecular machine can be repurposed by changing its subunit composition and regulation.
meiotic cohesin complex At A Glance
| GO ID | GO:0030893 |
|---|---|
| GO term | meiotic cohesin complex |
| Ontology | cellular_component |
| Synonym | nuclear meiotic cohesin complex |
| Major function | Mediates sister chromatid cohesion during meiosis and supports meiotic chromosome segregation |
| Subunit composition | Distinct from mitotic cohesin; includes meiosis-specific subunits such as REC8, STAG3, RAD21L and SMC1B in mammals |
| Associated processes | Synaptonemal complex assembly, crossover formation, centromere pairing, meiotic spindle assembly |
| Conservation | Found in organisms ranging from protists to plants and mammals, with lineage-specific subunit variation |
What Is GO:0030893?
According to the Gene Ontology, GO:0030893 (meiotic cohesin complex) is a cohesin complex that mediates sister chromatid cohesion during meiosis; it has a subunit composition distinct from that of the mitotic cohesin complex. In other words, it is the meiosis-specific form of the cohesin ring that holds sister chromatids together from meiotic S phase until the appropriate division, and it also participates in higher-order chromosome structures such as the synaptonemal complex.
Why Is meiotic cohesin complex Important in Cell Biology?
The meiotic cohesin complex is central to faithful chromosome segregation during meiosis, and its dysfunction is directly linked to aneuploidy, infertility and cancer. Because the complex is built from meiosis-specific subunits, it offers a unique window into how a conserved ring machine is retooled for a specialized division program. Understanding GO:0030893 also matters for reproductive biology, since errors in meiotic cohesion are a leading cause of miscarriages and chromosomal disorders.
• Ensures sister chromatid cohesion during meiosis I and II, preventing premature separation and aneuploidy.
• Supports synaptonemal complex assembly and crossover formation between homologs.
• Participates in centromere pairing, as shown for the maize cohesin subunit ZmSMC3.
• Regulates meiotic spindle assembly through accessory proteins such as Pds5A.
• Provides a model for studying how ring gates are specialized for meiotic division.
• Is linked to male germline nucleome organization through STAG3-cohesin.
• Offers targets for fertility research and reproductive medicine.
• Helps explain conserved and divergent features of cohesin across species, including protists.
• Can be studied with CRISPR knockout, knock-in and tagged alleles to dissect subunit-specific functions.
• Informs cancer biology because cohesin mutations are found in several malignancies.
Meiotic cohesin complex: components, assembly and molecular mechanism
Loading and establishment of meiotic cohesion
In simple terms: The cohesin ring is loaded onto chromosomes as cells enter meiosis so that sister chromatids stay together.
During meiotic entry, cohesin rings are loaded onto chromosomes and establish sister chromatid cohesion. The meiotic complex uses meiosis-specific subunits, and its dynamics are distinct from mitotic cohesin. In mammals, the meiotic cohesin complex includes REC8, STAG3, RAD21L and SMC1B, which replace or supplement mitotic subunits. Loading is a prerequisite for subsequent synaptonemal complex assembly and recombination.
Synaptonemal complex assembly and homolog pairing
In simple terms: Cohesin helps homologous chromosomes find each other and build the protein scaffold that holds them together.
The meiotic cohesin complex is required for synaptonemal complex assembly. In Drosophila oocytes, a dynamic meiotic cohesin complex regulates synaptonemal complex assembly, linking cohesion to homolog pairing. In maize, the cohesin subunit ZmSMC3 participates in meiotic centromere pairing, showing that cohesin functions extend beyond arm cohesion. These activities ensure that homologs are correctly aligned before segregation.
Stepwise release of cohesion and meiotic divisions
In simple terms: Cohesin is removed in two steps so that chromosomes separate correctly in meiosis I and meiosis II.
Meiosis requires stepwise loss of cohesion: arm cohesion is released in meiosis I, while centromeric cohesion is retained until meiosis II. The cohesin ring gates are specialized for meiotic cell division, enabling this two-step release. Accessory proteins such as Pds5A regulate meiotic spindle assembly, further coordinating cohesion with chromosome movement.
Subunit composition and ring architecture
In simple terms: The meiotic cohesin ring is built from a different set of protein subunits than the mitotic ring.
The meiotic cohesin complex has a subunit composition distinct from the mitotic complex. In mammals, meiosis-specific subunits include REC8, STAG3, RAD21L and SMC1B, whereas mitotic cells use RAD21 and STAG1/2. The STAG3-cohesin complex shapes the male germline nucleome, indicating that subunit identity influences higher-order chromatin organization. In some organisms, such as Tetrahymena, a single cohesin complex performs both mitotic and meiotic functions, highlighting evolutionary variation.
Regulation by accessory proteins and post-translational modifications
In simple terms: Other proteins and chemical modifications control when and where cohesin acts.
Cohesin function is regulated by accessory proteins and post-translational modifications. Pds5A governs meiotic spindle assembly via deubiquitination of Kif5B in oocytes, linking cohesin-associated factors to motor regulation. The dynamic behavior of meiotic cohesin in Drosophila oocytes further shows that regulation is temporally and spatially controlled. These regulatory layers ensure that cohesion is established, maintained and released at the correct times.
Key Genes Involved in GO:0030893 meiotic cohesin complex
The following genes and proteins are core components or regulators of the meiotic cohesin complex (GO:0030893) and are widely studied in meiosis research.
| Gene | Major Role | Research Relevance |
|---|---|---|
| REC8 | Meiosis-specific kleisin subunit of the cohesin ring | Essential for meiotic cohesion and stepwise release |
| STAG3 | Meiosis-specific stromal antigen subunit | Shapes male germline nucleome and is linked to infertility |
| RAD21L | Meiosis-specific kleisin paralog | Contributes to meiotic cohesin complexes in mammals |
| SMC1B | Meiosis-specific SMC subunit | Part of the meiotic cohesin ring in mammals |
| SMC3 | Core SMC subunit shared with mitotic cohesin | Participates in meiotic centromere pairing in maize |
| PDS5A | Cohesin-associated protein | Regulates meiotic spindle assembly via Kif5B deubiquitination |
| KIF5B | Kinesin motor protein | Target of Pds5A regulation in oocyte spindle assembly |
| SYCP1 | Synaptonemal complex protein | Assembly is regulated by meiotic cohesin dynamics |
| SYCP3 | Synaptonemal complex protein | Works with cohesin during synapsis |
| SMC1A | SMC subunit | Mitotic counterpart that helps define meiotic specificity |
| SMC2 | SMC subunit | Related SMC family member for comparative studies |
| RAD21 | Mitotic kleisin | Contrasts with meiotic REC8/RAD21L |
| STAG1 | Mitotic stromal antigen | Contrasts with meiotic STAG3 |
| STAG2 | Mitotic stromal antigen | Contrasts with meiotic STAG3 |
| WAPL | Cohesin release factor | Regulates cohesin dynamics in meiosis |
| PDS5B | Cohesin-associated protein | Paralog of PDS5A with related functions |
| ESCO1 | Cohesin acetyltransferase | Modifies cohesin to stabilize cohesion |
How Is meiotic cohesin complex Regulated?
Meiotic cohesin is regulated at multiple levels. Its subunit composition changes between mitotic and meiotic programs, with meiosis-specific subunits such as REC8, STAG3, RAD21L and SMC1B replacing or supplementing mitotic subunits. Accessory proteins such as Pds5A regulate meiotic spindle assembly through deubiquitination of Kif5B, linking cohesin to motor-driven chromosome movement. The ring gates themselves are specialized for meiotic division, enabling stepwise cohesion release. In Drosophila oocytes, the complex is dynamic and its behavior is coordinated with synaptonemal complex assembly. These regulatory mechanisms ensure that cohesion is established at the right time and released in the correct order.
meiotic cohesin complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| STAG3 | Infertility and germline nucleome organization | Knockout mouse or human cell line |
| REC8 | Aneuploidy and meiotic cohesion defects | Knockout and tagged knock-in models |
| PDS5A | Oocyte spindle assembly defects | Point mutation and knockout in oocytes |
| SMC3 | Centromere pairing defects | Knockout in maize or mammalian cells |
| RAD21L | Meiotic cohesion and fertility | Knockout and overexpression models |
Aneuploidy and reproductive disorders
Errors in meiotic cohesin function cause chromosome missegregation, leading to aneuploidy, which is a major cause of miscarriage and developmental disorders. Mutations in meiosis-specific cohesin subunits such as STAG3 have been linked to infertility, highlighting the clinical importance of GO:0030893.
Cancer
Cohesin subunits and regulators are mutated in several cancers, and the meiotic cohesin machinery provides a model for understanding how altered cohesion contributes to genomic instability. The STAG3-cohesin complex shapes the male germline nucleome, and related cohesin biology is relevant to cancer cell chromosome dynamics.
Germline and developmental biology
Because meiotic cohesin is essential for gamete formation, its dysfunction affects fertility and germline development. Studies in model organisms such as maize and Drosophila reveal conserved roles in centromere pairing and synaptonemal complex assembly that are relevant to human reproductive biology.
From meiotic cohesin complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a meiotic cohesin subunit cause cohesion defects? | CRISPR knockout cell line or mouse model |
| How does a specific point mutation affect ring function? | Point-mutation knock-in via CRISPR |
| Where and when is the complex assembled? | Tagged knock-in with fluorescent or epitope tag |
| Can overexpression rescue a cohesion defect? | Overexpression cell model |
| Which accessory proteins interact with the complex? | Proteomics and co-immunoprecipitation |
| How does cohesin regulate synaptonemal complex assembly? | Drosophila oocyte model |
How to Study the meiotic cohesin complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss-of-function phenotype | Testing requirement for meiotic cohesion |
| Live-cell imaging | Dynamic localization of cohesin | Studying synaptonemal complex assembly |
| Co-immunoprecipitation | Protein-protein interactions | Identifying accessory proteins |
| Mass spectrometry | Complex composition | Defining subunit repertoire |
| Chromosome spreads | Cohesion and synapsis | Meiotic progression analysis |
| Aneuploidy assays | Chromosome segregation errors | Linking cohesin defects to aneuploidy |
| Spindle assembly assays | Meiotic spindle integrity | Testing Pds5A and Kif5B regulation |
Genetic knockout and knockdown
CRISPR knockout of meiotic cohesin subunits such as REC8 or STAG3 allows researchers to test their requirement for cohesion, synaptonemal complex assembly and chromosome segregation. Knockdown approaches can complement knockout studies in cell lines where complete loss is lethal.
Imaging and live-cell analysis
Fluorescent tagging of cohesin subunits enables live-cell imaging of ring dynamics during meiosis. In Drosophila oocytes, dynamic meiotic cohesin complexes have been visualized in relation to synaptonemal complex assembly. Imaging of centromere pairing in maize has also revealed cohesin functions.
Proteomics and interaction studies
Affinity purification and mass spectrometry can identify subunits and accessory proteins of the meiotic cohesin complex, including Pds5A and Kif5B. These methods help define the composition of GO:0030893 in different organisms.
Chromosome segregation assays
Assays for aneuploidy, chromosome spreads and spindle assembly can measure the functional consequences of cohesin perturbation. Such assays are used to link molecular defects to meiotic outcomes.
How CRISPR Can Be Used to Study GO:0030893 meiotic cohesin complex
Knockout
CRISPR knockout of meiotic cohesin genes such as REC8, STAG3 or RAD21L can reveal their essential roles in cohesion, synaptonemal complex assembly and fertility. Knockout models are used to test whether a subunit is required for centromere pairing and chromosome segregation.
Point Mutation
Point-mutation knock-in allows structure-function analysis of cohesin ring gates and subunit interfaces. Because ring gates are specialized for meiotic division, targeted mutations can dissect stepwise cohesion release. Such models help distinguish separation-of-function from loss-of-function phenotypes.
Knock-in
Tagged knock-in of cohesin subunits enables visualization and biochemical purification of the endogenous complex. This approach is valuable for tracking dynamic meiotic cohesin complexes during synaptonemal complex assembly.
Overexpression
Overexpression models can test whether excess cohesin subunit perturbs meiotic progression or rescues cohesion defects. They are also useful for producing sufficient material for proteomic analysis of the complex.
How EDITGENE Supports meiotic cohesin complex Research
Researchers studying meiotic cohesin complex-related genes often need to determine whether a candidate gene is causally involved in cohesion, synaptonemal complex assembly or chromosome segregation. EDITGENE provides CRISPR-based cell models and screening services to accelerate this work.
Contact EDITGENE today to design your custom CRISPR model for meiotic cohesin complex research.
Frequently Asked Questions About meiotic cohesin complex
What is GO:0030893?
GO:0030893 is the Gene Ontology term for the meiotic cohesin complex, a cohesin complex that mediates sister chromatid cohesion during meiosis and has a subunit composition distinct from the mitotic cohesin complex.
What genes are involved in the meiotic cohesin complex?
Key genes include REC8, STAG3, RAD21L and SMC1B in mammals, along with core SMC subunits and accessory proteins such as PDS5A.
How does the meiotic cohesin complex differ from mitotic cohesin?
The meiotic complex uses meiosis-specific subunits such as REC8 and STAG3, whereas mitotic cohesin uses RAD21 and STAG1/2.
Why is meiotic cohesin important for fertility?
It ensures correct chromosome segregation during meiosis, and its dysfunction causes aneuploidy and infertility.
What happens if meiotic cohesin is knocked out?
Knockout of meiotic cohesin subunits impairs sister chromatid cohesion, synaptonemal complex assembly and chromosome segregation.
Is the meiotic cohesin complex conserved across species?
Yes, it is found from protists to plants and mammals, though subunit composition varies; in Tetrahymena a single cohesin complex performs both mitotic and meiotic functions.
How is the meiotic cohesin complex regulated?
It is regulated by subunit switching, accessory proteins such as Pds5A, and specialized ring gates that enable stepwise cohesion release.
What methods are used to study meiotic cohesin?
Common methods include CRISPR knockout, live-cell imaging, co-immunoprecipitation, mass spectrometry and chromosome segregation assays.
Which diseases are linked to meiotic cohesin defects?
Aneuploidy, infertility and some cancers have been linked to defects in meiotic cohesin subunits and regulators.
Can CRISPR be used to model meiotic cohesin function?
Yes, CRISPR knockout, point-mutation, knock-in and overexpression models are widely used to dissect meiotic cohesin function.
Conclusion
The meiotic cohesin complex (GO:0030893) is a specialized cohesin machine that mediates sister chromatid cohesion during meiosis and supports synaptonemal complex assembly, centromere pairing and stepwise chromosome segregation. Its distinct subunit composition and regulation make it a rich subject for studies of meiosis, fertility and genome stability. Continued research using CRISPR models and advanced imaging will clarify how this complex is assembled and controlled in health and disease.
References
- 1. Rankin S. 2015. Complex elaboration: making sense of meiotic cohesin dynamics.. FEBS J 282(13):2426-43 PMID: 25895170
- 2. Zhang J et al.. 2020. The Cohesin Complex Subunit ZmSMC3 Participates in Meiotic Centromere Pairing in Maize.. Plant Cell 32(4):1323-1336 PMID: 31996400
- 3. Ishiguro KI. 2019. The cohesin complex in mammalian meiosis.. Genes Cells 24(1):6-30 PMID: 30479058
- 4. Nagano M et al.. 2025. The mitotic STAG3-cohesin complex shapes male germline nucleome.. Nat Struct Mol Biol 32(11):2203-2218 PMID: 40855131
- 5. Howland M et al.. 2026. A dynamic meiotic cohesin complex regulates synaptonemal complex assembly in Drosophila oocytes.. Genetics 234(1) PMID: 42334453
- 6. Howard-Till RA et al.. 2013. A single cohesin complex performs mitotic and meiotic functions in the protist tetrahymena.. PLoS Genet 9(3):e1003418 PMID: 23555314
- 7. Liu Y et al.. 2025. Cohesin ring gates are specialized for meiotic cell division.. J Mol Cell Biol 16(10) PMID: 39401990
- 8. Zhang Y et al.. 2025. The cohesin-associated protein Pds5A governs the meiotic spindle assembly via deubiquitination of Kif5B in oocytes.. Sci Adv 11(15):eadt6159 PMID: 40215310
