identifier: METPO:1000692
label: spindle shaped
definition: A cell shape that is widest at the middle and tapers symmetrically toward
  pointed poles.
definition_source: DOI:10.1146/annurev-cellbio-101011-155745
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000666
synonyms:
- synonym_text: spindle
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
created_by: Anthea Guo
evidence:
- reference: DOI:10.1146/annurev-cellbio-101011-155745
  snippet: cell shape is genetically determined
  notes: Cell-shape review supports symmetric tapered shapes as a genetically determined
    outcome of polar wall patterning.
canonical_examples:
- taxon_id: NCBITaxon:1488
  taxon_label: Clostridium acetobutylicum
  note: "spindle-shaped on sporulation"
  reference: PMID:16346038
causal_graphs:
- graph_id: spindle_shaped_symmetric_taper
  title: Spindle-shape symmetric polar taper
  description: DOI-backed graph linking symmetric tapered polar wall growth and reduced
    end-cap radius to spindle morphology.
  nodes:
  - node_id: spindle_shaped_trait
    label: spindle shaped
    node_type: TRAIT
    grounding: METPO:1000692
    description: Cell widest at the middle and tapering symmetrically to pointed poles.
  - node_id: symmetric_polar_pg
    label: symmetric polar peptidoglycan growth
    node_type: BIOLOGICAL_PROCESS
    description: Tapered PG growth at both poles producing pointed ends.
  - node_id: reduced_end_cap_radius
    label: reduced end-cap radius
    node_type: BIOLOGICAL_PROCESS
    description: Narrowed cell-body radius near the poles.
  - node_id: spindle_geometry
    label: spindle geometry
    node_type: BIOLOGICAL_PROCESS
    description: Bilaterally symmetric tapered body geometry.
  - node_id: localized_pg_insertion
    label: localized peptidoglycan insertion
    node_type: BIOLOGICAL_PROCESS
    description: Spatially restricted incorporation of new peptidoglycan at distinct
      rates in defined cell locations.
  - node_id: non_spherical_morphology
    label: non-spherical morphology
    node_type: QUALITY
    description: A differentiated, non-spherical cell shape produced by spatially
      patterned wall growth.
  edges:
  - subject: symmetric_polar_pg
    predicate: produces
    object: reduced_end_cap_radius
    description: Symmetric polar growth produces reduced end-cap radius at both poles.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: polar growth
      notes: Supports polar PG growth as the producer of tapered ends.
    predicate_id: METPO:2000202
  - subject: reduced_end_cap_radius
    predicate: causes
    object: spindle_geometry
    description: Reduced end-cap radius at both poles yields spindle geometry.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: cell shape is genetically determined
      notes: Supports tapered geometry as a genetically determined shape outcome.
    predicate_id: biolink:causes
  - subject: spindle_geometry
    predicate: manifests as
    object: spindle_shaped_trait
    description: Spindle geometry manifests the spindle-shaped trait.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: cell shape is genetically determined
      notes: Supports the trait endpoint.
    predicate_id: METPO:2007400
  - subject: localized_pg_insertion
    predicate: required for
    object: non_spherical_morphology
    description: Spatially localized (non-dispersed) peptidoglycan insertion is required
      to generate any non-spherical, differentiated cell shape.
    evidence:
    - reference: DOI:10.3389/fmicb.2017.01264
      notes: To generate shapes other than a sphere, incorporation must occur at distinct
        rates in different locations and for defined periods of time. Broad mechanistic
        principle for non-spherical morphogenesis.
  - subject: localized_pg_insertion
    predicate: enables
    object: symmetric_polar_pg
    description: Generic localized PG insertion underlies the symmetric polar peptidoglycan
      growth that taper the poles.
    evidence:
    - reference: DOI:10.3389/fmicb.2017.01264
      notes: Localized, temporally defined PG incorporation is the general prerequisite
        for the symmetric polar growth that produces tapered spindle poles.
    predicate_id: RO:0002327
curation_history:
- timestamp: '2026-05-05T01:35:46.899347+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-11T22:45:00-07:00'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added DOI-backed definition and causal graph linking symmetric polar peptidoglycan
    growth and reduced end-cap radius to spindle morphology.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:31Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×1).
  llm_assisted: true
- timestamp: '2026-05-23T21:30:07Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2007400×1).
  llm_assisted: true
- timestamp: '2026-05-24T04:13:19Z'
  curator: claude
  action: RENAME_PREDICATE_LABELS
  changes: 'Renamed 1 causal-edge predicate label(s) to align with existing groundings:
    shapes → causes ×1.'
  llm_assisted: true
- timestamp: '2026-05-24T04:13:22Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:causes×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 2 evidence-backed generic edges (2 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:14Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002327×1).
  llm_assisted: true