identifier: METPO:1000669
label: crescent shaped
definition: A cell shape in which an organism has a curved crescent-like morphology
  with a concave inner side and a convex outer side.
definition_source: DOI:10.1016/S0092-8674(03)00935-8
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000666
synonyms:
- synonym_text: crescent-shaped
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
created_by: Luke Wang
evidence:
- reference: DOI:10.1016/S0092-8674(03)00935-8
  snippet: required for the vibrioid and helical shapes of Caulobacter
  notes: Supports crescentin as a bacterial cytoskeletal determinant of curved Caulobacter
    cell shape.
canonical_examples:
- taxon_id: NCBITaxon:155892
  taxon_label: Caulobacter vibrioides
  note: "Curved/crescent (vibrioid) cell; classic strain CB15, long called Caulobacter crescentus."
  reference: PMID:19383443
causal_graphs:
- graph_id: crescent_shaped_crescentin_curvature
  title: Crescent-shape crescentin curvature mechanism
  description: Evidence-backed causal sketch linking crescent morphology to crescentin
    localization, inner-curvature mechanical constraint, peptidoglycan growth bias,
    and curved cell-body geometry.
  nodes:
  - node_id: crescent_shaped_trait
    label: crescent shaped
    node_type: TRAIT
    grounding: METPO:1000669
    description: Curved crescent-like bacterial cell morphology.
  - node_id: crescentin
    label: crescentin
    node_type: GENE_OR_PROTEIN
    description: Intermediate-filament-like cytoskeletal protein encoded by creS.
    grounding: UniProtKB:A0A2N9AY16
  - node_id: inner_cell_curvature
    label: inner cell curvature
    node_type: CELLULAR_LOCALIZATION
    description: Concave side of a crescent-shaped cell.
  - node_id: peptidoglycan_growth_bias
    label: peptidoglycan growth bias
    node_type: BIOLOGICAL_PROCESS
    description: Differential wall growth or strain that bends the cell body.
  - node_id: crescent_cell_curvature
    label: crescent cell curvature
    node_type: BIOLOGICAL_PROCESS
    description: Maintenance of a curved crescent cell body.
  - node_id: pg_insertion_inner_curvature
    label: peptidoglycan insertion at inner curvature
    node_type: BIOLOGICAL_PROCESS
    description: Rate of new peptidoglycan insertion on the concave (inner) side of
      the cell.
  - node_id: differential_pg_insertion
    label: differential peptidoglycan insertion rates
    node_type: BIOLOGICAL_PROCESS
    description: Gradient of peptidoglycan insertion rates around the cell circumference.
  - node_id: crescentin_envelope_association
    label: crescentin envelope association
    node_type: STATE
    description: Attachment of crescentin to the cell envelope, required for its curvature
      function.
  edges:
  - subject: crescentin
    predicate: localizes to
    object: inner_cell_curvature
    description: Crescentin localizes along the inner curvature of the cell.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      snippet: localizes to the inner cell curvature
      notes: Supports crescentin as an inner-curvature-localized shape protein.
    predicate_id: biolink:located_in
  - subject: crescentin
    predicate: regulates
    object: peptidoglycan_growth_bias
    description: Crescentin mechanically constrains cell-wall growth to create differential
      curvature.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      snippet: mechanical control of cell growth
      notes: Supports a mechanical growth-control role for crescentin.
    predicate_id: RO:0002211
  - subject: peptidoglycan_growth_bias
    predicate: generates
    object: crescent_cell_curvature
    description: Biased peptidoglycan growth or strain generates curved geometry.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      snippet: bacterial cell curvature through mechanical control
      notes: Supports differential growth mechanics as a curvature mechanism.
    predicate_id: biolink:produces
  - subject: crescent_cell_curvature
    predicate: produces
    object: crescent_shaped_trait
    description: Curved cell-body geometry produces the crescent-shaped trait.
    evidence:
    - reference: DOI:10.1016/S0092-8674(03)00935-8
      snippet: required for the ... shapes of Caulobacter
      notes: Supports crescentin-dependent curved morphology as the trait endpoint.
    predicate_id: METPO:2000202
  - subject: crescentin
    predicate: decreases rate of
    object: pg_insertion_inner_curvature
    description: Crescentin reduces peptidoglycan insertion on the side where it is
      located, setting up a growth-rate gradient.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      notes: the crescentin structure would not only reduce peptidoglycan insertion
        at the side where crescentin is located but would also generate a gradient
        of increasing peptidoglycan growth rates
  - subject: pg_insertion_inner_curvature
    predicate: contributes to
    object: differential_pg_insertion
    description: Reduced inner-side insertion creates a gradient of differential peptidoglycan
      insertion rates around the circumference.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      notes: would also generate a gradient of increasing peptidoglycan growth rates
    predicate_id: RO:0002326
  - subject: differential_pg_insertion
    predicate: produces
    object: crescent_shaped_trait
    description: Differential peptidoglycan insertion rates around the cell circumference
      produce cell curvature.
    evidence:
    - reference: DOI:10.1038/emboj.2009.61
      notes: the crescentin structure caused differential peptidoglycan insertion
        rates around the cell circumference to produce cell curvature
    predicate_id: METPO:2000202
  - subject: crescentin_envelope_association
    predicate: required for
    object: crescent_shaped_trait
    description: Association of crescentin with the cell envelope is required to produce
      curvature; attachment-defective mutants fail to curve.
    evidence:
    - reference: DOI:10.1128/jb.01371-09
      notes: Envelope association is required for crescentin function (attachment-defective
        mutants fail to produce curvature)
curation_history:
- timestamp: '2026-05-05T01:35:46.886631+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-11T20:05:00-07:00'
  curator: codex
  action: CURATED_WITH_LITERATURE
  changes: Added DOI-backed definition and causal graph for crescentin, inner cell
    curvature, peptidoglycan growth bias, and crescent 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: '2026-05-23T08:21:50Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:located_in×1, biolink:produces×1).
  llm_assisted: true
- timestamp: '2026-05-24T05:05:14Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A2N9AY16×1).
  llm_assisted: true
- timestamp: '2026-05-26T05:00:48Z'
  curator: claude
  action: RENAME_PREDICATE_LABELS
  changes: 'Renamed 1 causal-edge predicate label(s) to align with existing groundings:
    constrains → regulates ×1.'
  llm_assisted: true
- timestamp: '2026-05-26T05:00:50Z'
  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 (3 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:0002326×1, METPO:2000202×1).
  llm_assisted: true