identifier: METPO:1000871
label: spore forming
definition: A sporulation in which an organism has the ability to produce endospores.
definition_source: DOI:10.1038/nrmicro2921
trait_category: MORPHOLOGY
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000870
synonyms:
- synonym_text: spore
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
- synonym_text: 'yes'
  synonym_type: RELATED_SYNONYM
  source: metpo.owl
evidence:
- reference: DOI:10.1038/nrmicro2921
  snippet: production of a highly resistant dormant cell type known as the spore
  notes: Supports spore forming as the ability to produce dormant resistant spores.
- reference: PMID:32660383
  snippet: Endospore formation in Bacillus subtilis
  notes: 'Organism example: Bacillus subtilis is described as endospore-forming.'
canonical_examples:
- taxon_id: NCBITaxon:1423
  taxon_label: Bacillus subtilis
  note: "Model endospore former and the paradigm for sporulation (strain 168)."
  reference: PMID:22091839
causal_graphs:
- graph_id: spore_forming_endospore_assembly
  title: Spore-forming endospore assembly mechanism
  description: Evidence-backed causal sketch linking forespore development to cortex
    synthesis, coat assembly, dipicolinic acid accumulation, and the spore-forming
    phenotype.
  nodes:
  - node_id: spore_forming_trait
    label: spore forming
    node_type: TRAIT
    grounding: METPO:1000871
    description: Ability to produce bacterial endospores.
  - node_id: forespore
    label: forespore
    node_type: CELLULAR_LOCALIZATION
    description: Developing spore compartment within the sporangium.
    grounding: GO:0042763
  - node_id: spore_cortex
    label: spore cortex
    node_type: CELLULAR_LOCALIZATION
    description: Specialized peptidoglycan layer surrounding the spore core.
  - node_id: spore_coat
    label: spore coat
    node_type: CELLULAR_LOCALIZATION
    description: Multilayered proteinaceous protective surface of the endospore.
    grounding: GO:0031160
  - node_id: dipicolinic_acid
    label: dipicolinic acid
    node_type: CHEMICAL
    description: Pyridine dicarboxylic acid enriched in bacterial spores.
    grounding: CHEBI:46837
  - node_id: resistant_endospore
    label: resistant endospore
    node_type: ORGANELLE
    description: Dormant stress-resistant spore produced by endospore-forming bacteria.
  - node_id: spoIID
    label: SpoIID
    node_type: GENE_OR_PROTEIN
    description: Morphogenetic protein required for forespore engulfment.
    grounding: UniProtKB:A0A0M6WLJ0
  - node_id: spoIIM
    label: SpoIIM
    node_type: GENE_OR_PROTEIN
    description: Morphogenetic protein required for forespore engulfment.
    grounding: UniProtKB:A5N7K0
  - node_id: spoIIP
    label: SpoIIP
    node_type: GENE_OR_PROTEIN
    description: Morphogenetic protein required for forespore engulfment.
    grounding: UniProtKB:A0A1S8R940
  - node_id: forespore_engulfment
    label: forespore engulfment
    node_type: BIOLOGICAL_PROCESS
    description: Engulfment of the forespore by the mother-cell membrane during sporulation.
  - node_id: cortex_synthesis
    label: cortex synthesis
    node_type: BIOLOGICAL_PROCESS
    description: Synthesis of spore cortex peptidoglycan in the intermembrane space.
  - node_id: coat_assembly
    label: spore coat assembly
    node_type: BIOLOGICAL_PROCESS
    description: Assembly of the multilayered proteinaceous spore coat.
  - node_id: spore_core_dormancy
    label: spore core protection and dormancy
    node_type: STATE
    description: Spore core protection, dehydration, and dormancy state.
  - node_id: spo0a_phosphorylated
    label: phosphorylated Spo0A (Spo0A~P)
    node_type: GENE_OR_PROTEIN
    description: Active phosphorylated master regulator of sporulation initiation.
  - node_id: spo0e_phosphatases
    label: Spo0E-family phosphatases
    node_type: GENE_OR_PROTEIN
    description: Spo0A-specific phosphatases providing negative control of sporulation
      initiation.
  edges:
  - subject: forespore
    predicate: develops into
    object: resistant_endospore
    description: The forespore compartment matures into a resistant endospore.
    evidence:
    - reference: DOI:10.1146/annurev.genet.30.1.297
      snippet: within which a spore is produced
      notes: Supports forespore development into the spore.
    predicate_id: biolink:develops_into
  - subject: spore_cortex
    predicate: contributes to
    object: resistant_endospore
    description: Cortex synthesis contributes to endospore structure and resistance.
    evidence:
    - reference: DOI:10.1038/nrmicro2921
      snippet: spore surface layers
      notes: Supports specialized spore layers as functional components of the endospore.
    predicate_id: RO:0002326
  - subject: spore_coat
    predicate: protects
    object: resistant_endospore
    description: The multilayered coat protects and structures the endospore surface.
    evidence:
    - reference: DOI:10.1038/nrmicro2921
      snippet: assembly and functions of the multilayered coat
      notes: Supports the spore coat as a protective assembly.
  - subject: dipicolinic_acid
    predicate: contributes to
    object: resistant_endospore
    description: Dipicolinic acid contributes to spore resistance and stability.
    evidence:
    - reference: DOI:10.1111/j.1365-2672.2005.02736.x
      snippet: mechanisms are responsible for the resistance of spores
      notes: Supports chemical and structural factors in Bacillus spore resistance.
    predicate_id: RO:0002326
  - subject: resistant_endospore
    predicate: manifests as
    object: spore_forming_trait
    description: Production of resistant endospores manifests the spore-forming trait.
    evidence:
    - reference: DOI:10.1038/nrmicro2921
      snippet: production of a highly resistant dormant cell type known as the spore
      notes: Supports the trait endpoint.
    predicate_id: METPO:2007400
  - subject: spoIID
    predicate: required for
    object: forespore_engulfment
    description: SpoIID is required for forespore engulfment.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: Genes spoIID, spoIIM, spoIIP are required for engulfment.
  - subject: spoIIM
    predicate: required for
    object: forespore_engulfment
    description: SpoIIM is required for forespore engulfment.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: Genes spoIID, spoIIM, spoIIP are required for engulfment.
  - subject: spoIIP
    predicate: required for
    object: forespore_engulfment
    description: SpoIIP is required for forespore engulfment.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: Genes spoIID, spoIIM, spoIIP are required for engulfment.
  - subject: cortex_synthesis
    predicate: contributes to
    object: resistant_endospore
    description: Cortex synthesis after engulfment contributes to mature spore formation.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: Cortex synthesis within the intermembrane space and coat assembly follow
        engulfment.
    predicate_id: RO:0002326
  - subject: coat_assembly
    predicate: contributes to
    object: spore_core_dormancy
    description: Spore coat assembly contributes to core protection, dehydration,
      and dormancy.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: Coat proteins influence core protection, spore-core dehydration and dormancy.
    predicate_id: RO:0002326
  - subject: spo0e_phosphatases
    predicate: negatively regulates
    object: spo0a_phosphorylated
    description: Spo0E-family phosphatases dephosphorylate and inhibit Spo0A~P.
    evidence:
    - reference: DOI:10.3390/microbiolres14020035
      notes: A second negative control is provided by Spo0E-family Spo0A-specific
        phosphatases.
curation_history:
- timestamp: '2026-05-05T01:35:46.917323+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-06T14:40:41-07:00'
  curator: codex
  action: CURATED_WITH_ORGANISM_EXAMPLE
  changes: Added Bacillus subtilis organism example with PMID-backed evidence.
  llm_assisted: true
- timestamp: '2026-05-11T21:00:00-07:00'
  curator: codex
  action: CURATED_WITH_LITERATURE
  changes: Replaced definition source with DOI-backed endospore source and added causal
    graph for forespore development, cortex, coat, dipicolinic acid, and resistant
    endospore formation.
  llm_assisted: true
- timestamp: '2026-05-20T03:35:31Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002326×2).
  llm_assisted: true
- timestamp: '2026-05-20T05:49:24Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (biolink:develops_into×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: '2026-06-14T05:51:46Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (GO:0042763×1, CHEBI:46837×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 6 evidence-backed generic edges (9 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:14Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002326×2).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:34Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (GO:0031160×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:20Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 3 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A0M6WLJ0×1, UniProtKB:A5N7K0×1, UniProtKB:A0A1S8R940×1).
  llm_assisted: true