identifier: traitmech:000285 label: Nemetona system definition: A phage defense system in which an organism possesses a Nemetona locus represented by a VCA0441 profile that can protect bacteria from bacteriophage infection. definition_source: DOI:10.1126/science.ads0768 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Nemetona synonym_type: EXACT_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md - synonym_text: VCA0441 synonym_type: RELATED_SYNONYM source: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md evidence: - reference: DOI:10.1126/science.ads0768 snippet: nearly 10% of the integron cassettes in the pandemic Vibrio cholerae strain encode novel antiphage functions notes: Darracq et al. support treating the newly discovered Vibrio cholerae SCI antiphage cassettes as bacterial anti-phage systems. - reference: DOI:10.1126/science.ads0768 snippet: Most of these novel systems have little or no similarity to previously known ones, with several providing defense through cell lysis or growth arrest notes: Darracq et al. support a conservative system record that does not assert a resolved Nemetona trigger, effector output, or universal pathway. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Nemetona | 10\.1126/science\.ads0768 | Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems notes: The DefenseFinder model registry maps the named Nemetona system to the Darracq et al. SCI antiphage-system paper. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Nemetona__VCA0441 | | Nemetona notes: The DefenseFinder HMM inventory records VCA0441 in the Nemetona model namespace. causal_graphs: - graph_id: nemetona_locus_restricts_phage title: Nemetona loci confer bacterial phage defense description: Conservative system-level sketch linking possession of a Nemetona locus to restricted bacteriophage propagation without asserting the unresolved phage trigger or molecular output. scope_status: NONMECHANISTIC scope_notes: The graph captures Nemetona as a named SCI-derived anti-phage system with a VCA0441 DefenseFinder profile while leaving its phage trigger, molecular substrate, antiviral effector output, and subtype breadth unresolved. nodes: - node_id: nemetona_locus label: Nemetona locus node_type: GENETIC_ELEMENT description: A Nemetona anti-phage defense locus represented in DefenseFinder by a VCA0441 profile. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the Nemetona system. - node_id: nemetona_system_trait label: Nemetona system node_type: TRAIT grounding: traitmech:000285 description: Possession of a genome-encoded Nemetona phage-defense system. - node_id: phage_defense_system label: phage defense system node_type: TRAIT grounding: traitmech:000209 description: Possession of one or more genome-encoded immune systems that inhibit bacteriophage infection. edges: - subject: nemetona_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: DefenseFinder maps Nemetona to an SCI anti-phage-system discovery paper and represents Nemetona loci through the VCA0441 component profile. evidence: - reference: DOI:10.1126/science.ads0768 snippet: nearly 10% of the integron cassettes in the pandemic Vibrio cholerae strain encode novel antiphage functions notes: Darracq et al. describe the newly discovered antiphage-system cohort that the DefenseFinder Nemetona registry row maps to the Nemetona system. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md snippet: Nemetona__VCA0441 | | Nemetona notes: The DefenseFinder HMM inventory supports VCA0441 as the Nemetona component profile. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: nemetona_system_trait description: Nemetona-mediated phage restriction realizes the Nemetona system trait. evidence: - reference: DOI:10.1126/science.ads0768 snippet: Most of these novel systems have little or no similarity to previously known ones, with several providing defense through cell lysis or growth arrest notes: Darracq et al. place the Nemetona discovery cohort in a set of novel bacterial systems that protect against phages. - subject: nemetona_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Nemetona system possession is a phage-defense-system trait. evidence: - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Nemetona | 10\.1126/science\.ads0768 | Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems notes: DefenseFinder associates Nemetona with the Darracq et al. bacterial antiphage-system paper. discussions: - discussion_id: nemetona-mechanism-gap prompt: Resolve Nemetona phage triggers and effector outputs before minting narrower Nemetona mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Darracq et al. and DefenseFinder support Nemetona as a named anti-phage system with a VCA0441 profile, but the trigger, molecular substrate, antiviral effector output, and subtype-specific mechanism are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#nemetona_locus_restricts_phage posed_by: codex posed_date: '2026-09-19' curation_history: - timestamp: '2026-09-19T16:03:52Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Nemetona system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, or prior proposal record; the replacement placeholder is reserved in proposals/metpo_traitmech_v162. llm_assisted: true