identifier: METPO:1000682 label: spore shaped definition: A cell shape in which an organism or differentiated cell has an endospore-like morphology, reflecting a dormant spore body with specialized protective layers. definition_source: DOI:10.1038/nrmicro2921 trait_category: MORPHOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000666 synonyms: - synonym_text: spore-shaped synonym_type: RELATED_SYNONYM source: metpo.owl created_by: Anthea Guo evidence: - reference: DOI:10.1038/nrmicro2921 snippet: structure of the endospore coat notes: Supports endospore morphology as a differentiated structure with specialized surface layers. causal_graphs: - graph_id: spore_shaped_endospore_layers title: Spore-shape endospore layer mechanism description: Evidence-backed causal sketch linking spore-shaped morphology to forespore engulfment, cortex formation, coat assembly, and dehydrated spore-core maturation. nodes: - node_id: spore_shaped_trait label: spore shaped node_type: TRAIT grounding: METPO:1000682 description: Endospore-like morphology. - node_id: forespore_engulfment label: forespore engulfment node_type: BIOLOGICAL_PROCESS description: Mother-cell membrane migration around the forespore. - node_id: cortex_formation label: cortex formation node_type: BIOLOGICAL_PROCESS description: Formation of the specialized spore cortex layer. - node_id: coat_assembly label: coat assembly node_type: BIOLOGICAL_PROCESS description: Assembly of the multilayered spore coat. - node_id: dehydrated_spore_core label: dehydrated spore core node_type: CELLULAR_LOCALIZATION description: Low-water spore core contributing to dormant spore properties. - node_id: mature_spore_body label: mature spore body node_type: ORGANELLE description: Differentiated spore structure with cortex, coat, and core. - node_id: spo0a_phosphorylation label: Spo0A phosphorylation node_type: MOLECULAR_FUNCTION description: Phosphorylation/activation of the master regulator Spo0A. - node_id: sporulation_initiation label: sporulation initiation node_type: BIOLOGICAL_PROCESS description: Entry into the sporulation differentiation program. - node_id: starvation label: starvation node_type: ENVIRONMENTAL_FACTOR description: Nutrient deprivation that triggers sporulation. - node_id: spoiva_protein label: SpoIVA node_type: GENE_OR_PROTEIN description: Morphogenetic protein that anchors coat material to the spore surface. - node_id: spovm_protein label: SpoVM node_type: GENE_OR_PROTEIN description: Morphogenetic protein required for spore coat encasement. grounding: UniProtKB:A0A2K8N6W1 - node_id: spovid_protein label: SpoVID node_type: GENE_OR_PROTEIN description: Morphogenetic protein required for spore coat encasement. grounding: UniProtKB:A0A0B5ANC0 - node_id: spore_encasement label: spore encasement node_type: BIOLOGICAL_PROCESS description: Morphological transition forming a full coat shell that encases the forespore. - node_id: cote_protein label: CotE node_type: GENE_OR_PROTEIN description: Morphogenetic protein required for outer coat assembly. grounding: UniProtKB:D5WPR1 - node_id: outer_coat label: outer coat node_type: CELLULAR_LOCALIZATION description: Outer layer of the multilayered spore coat. - node_id: safa_protein label: SafA node_type: GENE_OR_PROTEIN description: Morphogenetic protein required for inner coat assembly. grounding: UniProtKB:A0A0N1QUA1 - node_id: inner_coat label: inner coat node_type: CELLULAR_LOCALIZATION description: Inner layer of the multilayered spore coat. - node_id: spore_coat_surface label: spore coat node_type: CELLULAR_LOCALIZATION description: Multilayered spore coat anchored to the outer forespore membrane. grounding: GO:0031160 edges: - subject: forespore_engulfment predicate: establishes object: mature_spore_body description: Engulfment establishes the forespore as a distinct spore body. evidence: - reference: DOI:10.1146/annurev.genet.30.1.297 snippet: two-cell-chamber sporangium notes: Supports spore morphogenesis through compartmental development. - subject: cortex_formation predicate: builds layer of object: mature_spore_body description: Cortex formation builds a specialized spore structural layer. evidence: - reference: DOI:10.1038/nrmicro2921 snippet: spore surface layers notes: Supports specialized spore layers as components of mature morphology. - subject: coat_assembly predicate: builds layer of object: mature_spore_body description: Coat assembly builds the multilayered external spore structure. evidence: - reference: DOI:10.1038/nrmicro2921 snippet: mechanisms of coat assembly notes: Supports coat assembly as a morphogenetic process. - subject: dehydrated_spore_core predicate: contributes to object: mature_spore_body description: Core dehydration contributes to mature spore architecture and resistance. evidence: - reference: DOI:10.1111/j.1365-2672.2005.02736.x snippet: resistance of spores of Bacillus species notes: Supports spore core properties as part of resistant spore morphology. predicate_id: RO:0002326 - subject: mature_spore_body predicate: manifests as object: spore_shaped_trait description: Mature spore-body architecture manifests the spore-shaped trait. evidence: - reference: DOI:10.1038/nrmicro2921 snippet: highly resistant dormant cell type known as the spore notes: Supports the trait endpoint. predicate_id: METPO:2007400 - subject: spo0a_phosphorylation predicate: positively regulates object: sporulation_initiation description: Phosphorylation of the master regulator Spo0A initiates sporulation. evidence: - reference: DOI:10.1126/sciadv.adq0791 notes: Spo0A is the master regulator governing entry into sporulation; sporulation initiates upon phosphorylation of Spo0A (generalized across endospore formers). - subject: starvation predicate: positively regulates object: sporulation_initiation description: Starvation triggers entry into the sporulation differentiation program. evidence: - reference: DOI:10.1126/sciadv.adq0791 notes: Starvation triggers bacterial spore formation, a committed differentiation program. - subject: sporulation_initiation predicate: leads to object: forespore_engulfment description: Sporulation initiation leads to forespore engulfment. evidence: - reference: DOI:10.1126/sciadv.adq0791 notes: Sporulation is a committed differentiation program proceeding through forespore engulfment. - subject: spoiva_protein predicate: anchors object: spore_coat_surface description: SpoIVA anchors/tethers coat material to the spore surface (outer forespore membrane). evidence: - reference: DOI:10.1038/nrmicro2921 notes: SpoIVA functions to anchor coat material to the spore surface; required to tether the coat to the outer forespore membrane (conserved role). - subject: spovm_protein predicate: required for object: spore_encasement description: SpoVM is required for the morphological transition that encases the forespore. evidence: - reference: DOI:10.1038/nrmicro2921 notes: SpoVM and SpoVID are required for the morphological transition from a single scaffold cap to a full spherical shell that encases the forespore. - subject: spovid_protein predicate: required for object: spore_encasement description: SpoVID is required for spore encasement; mutants block formation of a full coat shell. evidence: - reference: DOI:10.1038/nrmicro2921 notes: SpoVID is explicitly required for spore encasement; spoVID mutants block formation of a full coat shell. - subject: cote_protein predicate: required for assembly of object: outer_coat description: CotE is required for assembly of the spore outer coat. evidence: - reference: DOI:10.1038/nrmicro2921 notes: SafA is necessary for inner coat assembly and CotE for outer coat assembly. - subject: safa_protein predicate: required for assembly of object: inner_coat description: SafA is required for assembly of the spore inner coat. evidence: - reference: DOI:10.1038/nrmicro2921 notes: SafA is necessary for inner coat assembly; SafA and CotE are respectively required for the deposition of the inner and outer coat. curation_history: - timestamp: '2026-05-05T01:35:46.893996+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-11T21:00:00-07:00' curator: codex action: CURATED_WITH_LITERATURE changes: Added DOI-backed definition and causal graph for forespore engulfment, cortex formation, coat assembly, dehydrated spore core, and mature spore-body 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 (RO:0002326×1). 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: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 8 evidence-backed generic edges (12 new nodes) from the deep-research report. 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 4 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:A0A2K8N6W1×1, UniProtKB:A0A0B5ANC0×1, UniProtKB:D5WPR1×1, UniProtKB:A0A0N1QUA1×1). llm_assisted: true