identifier: METPO:1000675
label: flask shaped
definition: A cell shape in which an organism has a bulbous body with a narrower neck-like
  extension at one pole.
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: flask
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
- synonym_text: flask-shaped
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1146/annurev-cellbio-101011-155745
  snippet: polar growth
  notes: Cell-shape review supports polarized peptidoglycan growth as a mechanism
    producing asymmetric flask-like morphology.
causal_graphs:
- graph_id: flask_shaped_asymmetric_polar_growth
  title: Flask-shape asymmetric polar growth
  description: DOI-backed graph linking unipolar peptidoglycan growth and tapered
    neck extension to flask-shaped cell morphology.
  nodes:
  - node_id: flask_shaped_trait
    label: flask shaped
    node_type: TRAIT
    grounding: METPO:1000675
    description: Bulbous cell body with a narrower polar neck.
  - node_id: unipolar_pg_growth
    label: unipolar peptidoglycan growth
    node_type: BIOLOGICAL_PROCESS
    description: Peptidoglycan synthesis localized to a single cell pole.
  - node_id: polar_neck_extension
    label: polar neck extension
    node_type: BIOLOGICAL_PROCESS
    description: Tapered extension of one pole producing the flask neck.
  - node_id: bulbous_body
    label: bulbous body
    node_type: BIOLOGICAL_PROCESS
    description: Wider rounded body region opposite the neck.
  - node_id: zonal_polar_pg_synthesis
    label: zonal polar peptidoglycan synthesis
    node_type: BIOLOGICAL_PROCESS
    description: Localized cell-wall (peptidoglycan) insertion at a cell pole.
  - node_id: polar_outgrowth
    label: polar envelope outgrowth
    node_type: BIOLOGICAL_PROCESS
    description: Asymmetric extension of one pole producing a stalk/prostheca-like
      neck.
  - node_id: pg_growth_zone_position
    label: position of polar PG growth zone
    node_type: QUALITY
    description: Spatial location of the localized cell-wall growth zone on the cell.
  - node_id: appendage_position_shape
    label: appendage position and shape
    node_type: QUALITY
    description: Where and how a polar neck-like extension forms on the cell.
  - node_id: bactofilin_lmdc_module
    label: bactofilin-M23 endopeptidase module
    node_type: PATHWAY
    description: Conserved scaffold/hydrolase morphogenetic module driving local cell-wall
      remodeling.
  - node_id: cell_wall_biosynthesis
    label: cell wall biosynthesis
    node_type: BIOLOGICAL_PROCESS
    description: Synthesis and remodeling of the peptidoglycan cell wall.
  - node_id: bactofilin_cytoskeleton
    label: bactofilin cytoskeleton
    node_type: GENE_OR_PROTEIN
    description: Bactofilin polymer scaffold marking sites of asymmetric wall growth.
  - node_id: asymmetric_compartment_growth
    label: asymmetric compartment growth
    node_type: BIOLOGICAL_PROCESS
    description: Outgrowth of stalk/bud-like compartments at a cell pole.
  edges:
  - subject: unipolar_pg_growth
    predicate: regulates
    object: polar_neck_extension
    description: Unipolar PG growth extends one pole into a narrower neck.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: polar growth
      notes: Supports unipolar growth as the mechanism for asymmetric pole extension.
    predicate_id: RO:0002211
  - subject: polar_neck_extension
    predicate: combines with
    object: bulbous_body
    description: A narrow polar neck adjoining a wider body yields flask geometry.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: cell shape is genetically determined
      notes: Supports asymmetric growth as a genetically determined shape program.
  - subject: bulbous_body
    predicate: manifests as
    object: flask_shaped_trait
    description: The combined neck+body geometry manifests flask morphology.
    evidence:
    - reference: DOI:10.1146/annurev-cellbio-101011-155745
      snippet: polar growth
      notes: Supports the trait endpoint via asymmetric polar growth.
    predicate_id: METPO:2007400
  - subject: zonal_polar_pg_synthesis
    predicate: produces
    object: polar_outgrowth
    description: Polarized cell-wall insertion is a general mechanism producing asymmetric
      bulb-plus-neck outgrowths.
    evidence:
    - reference: DOI:10.1371/journal.pbio.1002565
      notes: Caulobacter prostheca arises from zonal growth at the pole; general mechanism
        for asymmetric morphologies.
    predicate_id: METPO:2000202
  - subject: pg_growth_zone_position
    predicate: regulates
    object: appendage_position_shape
    description: Moving the localized growth zone changes where neck-like extensions
      form.
    evidence:
    - reference: DOI:10.1371/journal.pbio.1002565
      notes: Asticcacaulis prosthecate variants result from repositioning growth zones
        to subpolar/bilateral sites.
    predicate_id: RO:0002211
  - subject: bactofilin_lmdc_module
    predicate: regulates
    object: cell_wall_biosynthesis
    description: Conserved scaffold/hydrolase module promotes local changes in the
      mode of cell wall biosynthesis underlying complex shapes.
    evidence:
    - reference: DOI:10.7554/elife.86577.2
      notes: Bactofilins and M23 peptidases form a conserved functional module that
        promotes local changes in cell wall biosynthesis.
    predicate_id: RO:0002211
  - subject: bactofilin_cytoskeleton
    predicate: regulates
    object: asymmetric_compartment_growth
    description: Bactofilin scaffold constrains polar compartment growth; its loss
      causes unconstrained asymmetric outgrowth.
    evidence:
    - reference: DOI:10.7554/elife.86577.2
      notes: Loss of bactofilins causes unconstrained growth of the stalk and bud
        compartments.
    predicate_id: RO:0002211
curation_history:
- timestamp: '2026-05-05T01:35:46.890141+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 unipolar peptidoglycan
    growth and neck extension to flask-shaped morphology.
  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:
    drives → regulates ×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
    (RO:0002211×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 4 evidence-backed generic edges (8 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:13Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 4 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002211×3, METPO:2000202×1).
  llm_assisted: true