identifier: METPO:1000690
label: fusiform shaped
definition: A cell shape that is wide in the middle and tapers at both ends.
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: fusiform
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1146/annurev-cellbio-101011-155745
  snippet: cell shape is genetically determined
  notes: Cell-shape review supports tapered cell ends as a genetically determined
    geometry maintained by graded wall synthesis.
- reference: DOI:10.1111/1462-2920.13731
  snippet: Fusobacterium nucleatum
  notes: Fusobacterium-genome review supports fusiform morphology in the Fusobacterium
    genus.
canonical_examples:
- taxon_id: NCBITaxon:851
  taxon_label: Fusobacterium nucleatum
  note: "Spindle/fusiform (tapered-end) rod; model oral anaerobe."
  reference: https://www.ncbi.nlm.nih.gov/books/NBK8438/
causal_graphs:
- graph_id: fusiform_shaped_tapered_polar_growth
  title: Fusiform-shape tapered polar growth
  description: DOI-backed graph linking graded polar peptidoglycan growth and reduced
    end-cap radius to fusiform tapered morphology.
  nodes:
  - node_id: fusiform_shaped_trait
    label: fusiform shaped
    node_type: TRAIT
    grounding: METPO:1000690
    description: Cell wider at middle and tapering at both poles.
  - node_id: graded_polar_pg
    label: graded polar peptidoglycan growth
    node_type: BIOLOGICAL_PROCESS
    description: Polar PG growth with reduced incorporation toward the cell tips.
  - node_id: end_cap_taper
    label: end-cap taper
    node_type: BIOLOGICAL_PROCESS
    description: Reduction in radius near the cell poles producing pointed ends.
  - node_id: tapered_geometry
    label: tapered geometry
    node_type: BIOLOGICAL_PROCESS
    description: Cell-body geometry that narrows toward both poles.
  - node_id: mreb
    label: MreB
    node_type: GENE_OR_PROTEIN
    description: Bacterial actin homolog that orients peptidoglycan synthesis to maintain
      cell shape.
    grounding: UniProtKB:A0A1B1UYY2
  - node_id: lateral_pg_synthesis
    label: lateral peptidoglycan synthesis
    node_type: BIOLOGICAL_PROCESS
    description: Sidewall PG incorporation that sustains elongated cell geometry.
  - node_id: rodz
    label: RodZ
    node_type: GENE_OR_PROTEIN
    description: MreB-associated shape protein modulating MreB localization and elongasome
      assembly.
    grounding: UniProtKB:H1XNL6
  - node_id: mreb_localization
    label: MreB polymer localization/assembly
    node_type: BIOLOGICAL_PROCESS
    description: Geometric localization and assembly of the MreB actin cytoskeleton.
  - node_id: elongasome
    label: elongasome complex
    node_type: CELLULAR_LOCALIZATION
    description: Lateral wall-growth machinery containing MreB, RodA, PBP2, RodZ,
      MreC, MreD.
  - node_id: mrec
    label: MreC
    node_type: GENE_OR_PROTEIN
    description: Elongasome component that activates PBP2 and RodA synthesis functions.
    grounding: UniProtKB:A0A1L9R356
  - node_id: pbp2
    label: PBP2
    node_type: GENE_OR_PROTEIN
    description: Class B PBP in the elongasome coupled to RodA for rod-like wall growth.
    grounding: UniProtKB:A0A2D2D7X6
  - node_id: roda
    label: RodA
    node_type: GENE_OR_PROTEIN
    description: SEDS glycosyltransferase mediating lateral PG incorporation with
      PBP2.
    grounding: UniProtKB:A0A0H2X1V4
  - node_id: ftsw
    label: FtsW
    node_type: GENE_OR_PROTEIN
    description: SEDS divisome polymerase for septal PG incorporation.
    grounding: UniProtKB:A0A0E1R950
  - node_id: septal_pg_incorporation
    label: septal peptidoglycan incorporation
    node_type: BIOLOGICAL_PROCESS
    description: Division-site PG synthesis relevant to end-shaping and growth partitioning.
  edges:
  - subject: graded_polar_pg
    predicate: produces
    object: end_cap_taper
    description: Graded PG growth produces reduced end-cap radius.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: polar growth
      notes: Supports polar PG growth as the mechanism producing tapered ends.
    predicate_id: METPO:2000202
  - subject: end_cap_taper
    predicate: causes
    object: tapered_geometry
    description: End-cap taper at both poles yields the fusiform body 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: tapered_geometry
    predicate: manifests as
    object: fusiform_shaped_trait
    description: Tapered geometry at both poles manifests the fusiform-shaped trait.
    evidence:
    - reference: DOI:10.1111/1462-2920.13731
      snippet: Fusobacterium nucleatum
      notes: Supports fusiform morphology as the trait endpoint.
    predicate_id: METPO:2007400
  - subject: mreb
    predicate: guides
    object: lateral_pg_synthesis
    description: MreB filaments orient lateral PG synthesis to maintain rod-like cell
      shape.
    evidence:
    - reference: DOI:10.1038/s41579-020-0366-3
      notes: MreB orients peptidoglycan synthesis to generate or maintain a smooth
        cylindrical rod shape.
  - subject: rodz
    predicate: regulates
    object: mreb_localization
    description: RodZ modulates geometric localization and assembly of MreB.
    evidence:
    - reference: DOI:10.1186/s12964-025-02373-y
      notes: RodZ modulates geometric localization of MreB and is required for proper
        MreB cytoskeleton assembly.
    predicate_id: RO:0002211
  - subject: rodz
    predicate: scaffolds
    object: elongasome
    description: RodZ provides a scaffold for the elongasome via MreB, RodA, PBP2,
      PBP1A/1B.
    evidence:
    - reference: DOI:10.1038/s41579-020-0366-3
      notes: RodZ interacts with MreB, RodA, PBP2 and PBP1A/1B, providing a scaffold
        for the elongasome.
  - subject: mrec
    predicate: activates
    object: pbp2
    description: MreC induces a structural change in PBP2 promoting its TPase activity.
    evidence:
    - reference: DOI:10.1038/s41579-020-0366-3
      notes: MreC induces a structural change in PBP2, promoting PBP2 TPase and RodA
        GTase activity.
    predicate_id: RO:0002213
  - subject: roda
    predicate: required for
    object: lateral_pg_synthesis
    description: SEDS protein RodA with cognate bPBP mediates lateral PG incorporation.
    evidence:
    - reference: DOI:10.1016/j.mib.2021.01.011
      notes: SEDS proteins RodA/FtsW with cognate bPBPs mediate lateral versus septal
        PG incorporation.
  - subject: ftsw
    predicate: required for
    object: septal_pg_incorporation
    description: FtsW with cognate bPBP mediates septal PG incorporation.
    evidence:
    - reference: DOI:10.1016/j.mib.2021.01.011
      notes: FtsW with cognate bPBP mediates septal PG incorporation.
curation_history:
- timestamp: '2026-05-05T01:35:46.898157+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 causal graph linking graded polar peptidoglycan growth
    and end-cap taper to fusiform 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: '2026-05-24T04:13:21Z'
  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 6 evidence-backed generic edges (10 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:13Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002211×1, RO:0002213×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:21:19Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A1B1UYY2×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:19Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 5 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:H1XNL6×1, UniProtKB:A0A1L9R356×1, UniProtKB:A0A2D2D7X6×1, UniProtKB:A0A0H2X1V4×1,
    UniProtKB:A0A0E1R950×1).
  llm_assisted: true