GO:0005819 spindle: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0005819 (spindle) is the microtubule-based cellular machine that segregates duplicated chromosomes during mitosis and meiosis.
• Spindle assembly is a self-organization process driven by microtubule nucleation, motor proteins, and spatial cues from centrosomes or acentriolar pathways.
• Spindle density and architecture vary across cell types and species, with the Xenopus spindle being as dense as the surrounding cytoplasm.
• Human spindle variability is substantial and may contribute to aneuploidy and disease.
• Disrupted spindle function is linked to cancer, reproductive failure, and neurodegenerative conditions.
• CRISPR-based models (KO, point mutation, knock-in, overexpression) enable causal dissection of spindle gene function.
Description
The spindle (GO:0005819) is a dynamic, microtubule-based structure that assembles between opposite poles of a dividing eukaryotic cell to move duplicated chromosomes apart. It is essential for faithful genome segregation in mitosis and meiosis, and its dysfunction leads to aneuploidy, developmental defects, and disease. Understanding spindle biology requires integrating cell biology, genetics, and advanced imaging, and the spindle is a major target for cancer therapeutics and reproductive research.
spindle At A Glance
| GO ID | GO:0005819 |
|---|---|
| GO term | spindle |
| Ontology | cellular_component |
| Synonym | none |
| Major function | Chromosome segregation during mitosis and meiosis |
| Composition | Microtubules, motor proteins, and associated molecules |
| Location | Between opposite poles of a dividing eukaryotic cell |
| Process context | Mitosis and meiosis |
What Is GO:0005819?
According to the Gene Ontology, GO:0005819 (spindle) is defined as the array of microtubules and associated molecules that forms between opposite poles of a eukaryotic cell during mitosis or meiosis and serves to move the duplicated chromosomes apart. This definition encompasses the dynamic microtubule network, motor proteins, and regulatory factors that together ensure accurate chromosome segregation.
Why Is spindle Important in Cell Biology?
The spindle is fundamental to life because it ensures the equal distribution of genetic material to daughter cells. Errors in spindle assembly or function cause aneuploidy, which is a hallmark of cancer and a leading cause of miscarriage and developmental disorders. Moreover, spindle abnormalities are observed in neurodegenerative conditions such as Alzheimer's disease, where sleep spindle deficits are reported. Studying the spindle therefore has broad implications for cancer biology, reproductive medicine, and neuroscience.
• Ensures accurate chromosome segregation during cell division.
• Prevents aneuploidy, a common feature of cancer cells.
• Critical for meiosis and fertility; acentriolar spindle assembly in female meiosis is unique and error-prone.
• Spindle defects are linked to neurodegenerative diseases like Alzheimer's.
• Spindle density and architecture influence mechanical properties of dividing cells.
• Human spindle variability may underlie individual differences in drug responses.
• Target for anti-mitotic chemotherapies (e.g., taxanes, vinca alkaloids).
• Spindle cell tumors (e.g., spindle cell lipoma) are a distinct pathological entity.
• Spindle-dependent memory consolidation highlights its role beyond cell division.
• Model organisms like Xenopus provide insights into spindle self-organization.
What Happens During spindle?
Spindle Assembly and Self-Organization
In simple terms: The spindle builds itself from microtubules that grow and shrink until they form a bipolar structure.
Spindle assembly begins with microtubule nucleation, often from centrosomes, and is refined by motor proteins and crosslinkers that organize microtubules into a bipolar array. In Xenopus egg extracts, the spindle is as dense as the surrounding cytoplasm, indicating that self-organization occurs without a sharp boundary. This process is highly dynamic and stochastic, with microtubule choreography ensuring proper chromosome capture.
Chromosome Capture and Alignment
In simple terms: The spindle attaches to chromosomes and lines them up in the middle of the cell.
During prometaphase, microtubules search for and attach to kinetochores on chromosomes. This attachment is mediated by motor proteins and regulatory kinases. Once attached, chromosomes align at the metaphase plate, a process that requires tension sensing and error correction. In female meiosis, acentriolar spindle assembly leads to a higher error rate, contributing to aneuploidy.
Chromosome Segregation and Spindle Elongation
In simple terms: The spindle pulls sister chromatids apart and elongates to separate the two sets of chromosomes.
At anaphase, sister chromatids are pulled to opposite poles by shortening kinetochore microtubules and sliding of polar microtubules. Spindle elongation is driven by motor proteins and microtubule sliding, ensuring that each daughter cell receives a complete set of chromosomes. Defects in this step can lead to lagging chromosomes and micronuclei formation.
Spindle Disassembly and Cytokinesis
In simple terms: After chromosomes are separated, the spindle breaks down and the cell divides.
Following chromosome segregation, the spindle disassembles, and the cell undergoes cytokinesis. Spindle disassembly is regulated by mitotic kinases and phosphatases, and its timing is critical for preventing aneuploidy. In some cell types, spindle remnants contribute to midbody formation and abscission.
Key Genes Involved in GO:0005819 spindle
The following genes and proteins are core components and regulators of the spindle, with well-documented roles in its assembly, function, and regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TUBA1A | Alpha-tubulin, major microtubule subunit | Mutations cause tubulinopathies and spindle defects |
| TUBB | Beta-tubulin, major microtubule subunit | Target of anti-mitotic drugs; mutations affect spindle |
| KIF11 | Eg5 kinesin, bipolar spindle assembly | Inhibitor targets in cancer; essential for spindle |
| DYNC1H1 | Dynein heavy chain, spindle positioning | Mutations linked to neurodevelopmental disorders |
| NUMA1 | Nuclear mitotic apparatus protein, spindle organization | Regulates spindle pole focusing |
| TPX2 | Microtubule nucleation and spindle assembly | Activates Aurora A; target for cancer therapy |
| AURKA | Aurora kinase A, centrosome maturation | Overexpressed in cancers; regulates spindle |
| PLK1 | Polo-like kinase 1, mitotic progression | Inhibitor in clinical trials; spindle checkpoint |
| BUB1 | Spindle assembly checkpoint kinase | Mutations cause aneuploidy and cancer |
| MAD2L1 | Spindle checkpoint component | Defects lead to chromosomal instability |
| CDC20 | Activator of anaphase-promoting complex | Regulates spindle checkpoint silencing |
| CLASP1 | Microtubule plus-end tracking protein | Regulates spindle microtubule dynamics |
| HAUS8 | Augmin complex, microtubule nucleation | Essential for spindle assembly |
| KNTC1 | Kinetochore-associated protein | Required for chromosome segregation |
| NDC80 | Kinetochore component | Links chromosomes to microtubules |
| SPDL1 | Spindle assembly checkpoint protein | Regulates mitotic arrest |
| TP53 | Tumor suppressor, spindle checkpoint | Mutations allow aneuploidy |
How Is spindle Regulated?
Spindle assembly and function are tightly regulated by mitotic kinases (e.g., CDK1, Aurora A, PLK1) and phosphatases that control microtubule dynamics, motor protein activity, and checkpoint signaling. The spindle assembly checkpoint (SAC) monitors kinetochore-microtubule attachments and delays anaphase until all chromosomes are properly aligned. In female meiosis, acentriolar spindle assembly is regulated by distinct pathways involving Ran-GTP and chromosomal gradients. Additionally, spindle density and size are modulated by cytoplasmic factors, as shown in Xenopus extracts.
spindle and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| BUB1 | Cancer, aneuploidy | Knockout in cancer cell lines; point mutation |
| MAD2L1 | Chromosomal instability | Knockout in HCT116; overexpression |
| AURKA | Breast cancer, leukemia | Point mutation (activation); knock-in |
| PLK1 | Lung cancer, lymphoma | Knockout; overexpression; inhibitor studies |
| TP53 | Li-Fraumeni syndrome, cancer | Knock-in of mutant p53; knockout |
Cancer and Aneuploidy
Spindle defects are a major cause of aneuploidy, a hallmark of many cancers. Mutations in spindle checkpoint genes such as BUB1 and MAD2L1 lead to chromosomal instability and tumor progression. Overexpression of Aurora A and PLK1 is common in various cancers and is associated with poor prognosis. Anti-mitotic drugs targeting spindle microtubules (e.g., taxanes) are widely used in chemotherapy.
Reproductive Failure and Meiotic Errors
In mammalian female meiosis, the spindle assembles without centrosomes, relying on acentriolar pathways. Perturbations in this process lead to high rates of aneuploidy in oocytes, contributing to infertility, miscarriage, and Down syndrome. Understanding acentriolar spindle assembly is therefore critical for reproductive medicine.
Neurodegeneration and Sleep Spindles
Although distinct from the mitotic spindle, sleep spindles are thalamocortical oscillations implicated in memory consolidation. Abnormalities in sleep spindles are associated with Alzheimer's disease, suggesting a link between spindle-related neural circuits and neurodegeneration. Spindle-dependent memory consolidation has been supported by meta-analyses.
Spindle Cell Tumors
Spindle cell tumors, such as spindle cell lipoma and spindle cell vascular tumors, are a heterogeneous group of mesenchymal neoplasms. Their diagnosis relies on histopathological features, and molecular markers are increasingly used. These tumors are distinct from mitotic spindle dysfunction but share the 'spindle' nomenclature.
From spindle-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate spindle assembly? | Knockout cell lines (e.g., HeLa, RPE1) followed by live imaging |
| Does a point mutation in gene X affect spindle checkpoint? | Point mutation knock-in via CRISPR |
| Does overexpression of gene X cause aneuploidy? | Doxycycline-inducible overexpression |
| How does gene X localize during mitosis? | Endogenous GFP knock-in |
| What is the role of gene X in meiosis? | Oocyte-specific knockout or knock-in mouse models |
| Can gene X be targeted for cancer therapy? | CRISPR library screening for synthetic lethality |
How to Study the spindle Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Spindle dynamics, chromosome segregation | Assessing mutant phenotypes |
| Immunofluorescence | Spindle structure, protein localization | Fixed-cell analysis of spindle defects |
| Mass spectrometry | Spindle proteome, post-translational modifications | Identifying novel spindle components |
| CRISPR knockout screening | Gene essentiality for spindle function | Discovering new regulators |
| RNA-seq | Transcriptional changes upon spindle perturbation | Pathway analysis |
| Proximity labeling (BioID) | Spindle protein interactome | Mapping protein networks |
| Single-cell imaging | Heterogeneity in spindle morphology | Human spindle variability studies |
Live-Cell Imaging of Spindle Dynamics
Live-cell imaging using fluorescently labeled tubulin and DNA allows real-time visualization of spindle assembly, chromosome alignment, and segregation. This method is essential for assessing spindle morphology, dynamics, and defects in mutant cells.
Proteomics and Interactomics
Mass spectrometry-based proteomics can identify spindle-associated proteins and their post-translational modifications. Proximity labeling (e.g., BioID) and immunoprecipitation coupled to mass spectrometry reveal the spindle interactome.
CRISPR Screening for Spindle Regulators
Genome-wide CRISPR knockout or activation screens can identify genes required for spindle assembly, chromosome segregation, or resistance to anti-mitotic drugs. These screens are powerful for discovering novel spindle regulators.
Transcriptomics and Single-Cell Analysis
RNA-seq and single-cell transcriptomics reveal gene expression changes in response to spindle perturbations, providing insights into compensatory pathways and cell cycle regulation.
How CRISPR Can Be Used to Study GO:0005819 spindle
Knockout
CRISPR knockout of spindle genes (e.g., KIF11, AURKA) in cell lines leads to mitotic arrest, spindle defects, and cell death. These models are used to study gene essentiality and to validate drug targets.
Point Mutation
Introducing point mutations (e.g., in TUBA1A or TUBB) via CRISPR allows precise modeling of tubulinopathies and drug-resistant alleles. These models help dissect the molecular basis of spindle dysfunction.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) at endogenous loci enables real-time tracking of spindle proteins without overexpression artifacts. This approach is ideal for studying protein dynamics and localization.
Overexpression
CRISPR activation (CRISPRa) or cDNA overexpression can model gene amplification events observed in cancer (e.g., AURKA, PLK1). Overexpression models are useful for studying oncogenic transformation and drug resistance.
How EDITGENE Supports spindle Research
Researchers studying spindle-related genes often need to determine whether a candidate gene is causally involved in spindle assembly, chromosome segregation, or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to generate precisely engineered cell models, enabling rigorous functional studies.
Contact EDITGENE today to design your custom CRISPR model for spindle research.
Frequently Asked Questions About spindle
What is the spindle (GO:0005819)?
The spindle is a microtubule-based cellular structure that segregates chromosomes during mitosis and meiosis.
What genes are involved in spindle assembly?
Key genes include TUBA1A, TUBB, KIF11, AURKA, PLK1, and BUB1, among many others.
How is the spindle regulated?
The spindle is regulated by mitotic kinases (CDK1, Aurora A, PLK1) and the spindle assembly checkpoint.
What diseases are associated with spindle defects?
Spindle defects are linked to cancer, aneuploidy, infertility, and neurodegenerative diseases.
What is the role of the spindle in meiosis?
In meiosis, the spindle segregates homologous chromosomes and sister chromatids; female meiosis uses acentriolar spindle assembly.
How can I study spindle function in the lab?
Common methods include live-cell imaging, immunofluorescence, CRISPR screening, and proteomics.
What is the spindle assembly checkpoint?
The SAC is a surveillance mechanism that delays anaphase until all chromosomes are properly attached to the spindle.
Are there drugs that target the spindle?
Yes, taxanes and vinca alkaloids target microtubules, and inhibitors of Aurora A and PLK1 are in clinical trials.
What is the difference between mitotic and meiotic spindle?
Mitotic spindle segregates sister chromatids in somatic cells, while meiotic spindle segregates homologous chromosomes and sister chromatids in germ cells.
How does CRISPR help study the spindle?
CRISPR enables knockout, point mutation, knock-in, and overexpression of spindle genes to dissect their functions.
Conclusion
The spindle (GO:0005819) is a dynamic and essential cellular machine that ensures accurate chromosome segregation. Its dysfunction is implicated in cancer, reproductive failure, and neurodegeneration, making it a critical area of research. Advanced CRISPR tools and imaging technologies continue to unravel the complexities of spindle assembly and regulation, offering new opportunities for therapeutic intervention.
References
- 1. Kumral D et al.. 2023. Spindle-dependent memory consolidation in healthy adults: A meta-analysis.. Neuropsychologia 189:108661 PMID: 37597610
- 2. Van Treeck BJ et al.. 2019. Updates in spindle cell/pleomorphic lipomas.. Semin Diagn Pathol 36(2):105-111 PMID: 30850230
- 3. Sridhara A et al.. 2024. Microtubule choreography: spindle self-organization during cell division.. Biophys Rev 16(5):613-624 PMID: 39618782
- 4. Gonzalez C et al.. 2022. Human Spindle Variability.. J Neurosci 42(22):4517-4537 PMID: 35477906
- 5. Blengini CS et al.. 2022. Acentriolar spindle assembly in mammalian female meiosis and the consequences of its perturbations on human reproduction†.. Biol Reprod 106(2):253-263 PMID: 34791041
- 6. Weng YY et al.. 2020. Sleep spindle abnormalities related to Alzheimer's disease: a systematic mini-review.. Sleep Med 75:37-44 PMID: 32853916
- 7. Marušić Z et al.. 2017. Histopathology of Spindle Cell Vascular Tumors.. Surg Pathol Clin 10(2):345-366 PMID: 28477885
- 8. Biswas A et al.. 2021. The Xenopus spindle is as dense as the surrounding cytoplasm.. Dev Cell 56(7):967-975.e5 PMID: 33823135
