identifier: traitmech:000686
label: haptocyst discharge
definition: A physiological phenotype in which a microbial cell releases material
  from haptocysts to the cell exterior.
definition_source: DOI:10.1515/znc-1984-7-821
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1515/znc-1984-7-821
  snippet: The fine structure of haptocysts, characteristic organelles of most suctorians,
    is described during the resting state and the discharge after contact with the
    prey.
  notes: Benwitz 1984, English abstract reproduced at https://www.nies.go.jp/chiiki1/protoz/refere/id4999/4538.htm,
    read directly on 2026-10-10. Crossref confirms the DOI, title, author and original
    1984 publication; later online dates are not the experiment year. In Ephelota
    gemmipara the abstract reports prey-contact discharge, continuity of the haptocyst
    membrane with the tentacle plasma membrane, and attachment of internal haptocyst
    structures to the perforated prey pellicle. It explicitly reports no predator-prey
    plasma-membrane fusion in Ephelota. These observations support release to the
    cell exterior, not cell-cell fusion or merely possession of haptocysts. The publisher
    PDF was unavailable; figures and full Methods were not visually audited. No universal
    cargo chemistry or trigger is inferred.
- reference: DOI:10.1007/BF00331480
  snippet: By these haptocysts the tentacle is attached to the prey.
  notes: Bardele and Grell 1967, PMID:4971424. Publisher English Summary points 1-2
    at https://link.springer.com/article/10.1007/BF00331480 read directly on 2026-10-10.
    The source identifies the tentacular organelles in Acineta tuberosa as haptocysts
    and describes prey attachment. This is independent organelle-identity and attachment
    evidence, not a second direct discharge experiment. Its ingestion tube hypothesis
    is not a demonstrated haptocyst release mechanism. Full text is subscription-only
    and was not inspected.
discussions:
- discussion_id: haptocyst-discharge-scope-and-parent
  prompt: Resolve the exocytosis placement and historical extrusome terminology.
  kind: CURATION_TODO
  status: OPEN
  rationale: Retain phenotype METPO:1000059 pending broader hierarchy review. Benwitz
    supports organelle-plasma-membrane continuity in Ephelota, not predator-prey membrane
    fusion. This supports an exocytotic interpretation in that system but does not
    establish the fusion-pore differentia of exocytosis traitmech:000637 throughout
    the unqualified class. That placement is unresolved, not excluded. Mere possession,
    docking, prey attachment, ingestion or nonspecific cell lysis alone does not demonstrate
    discharge. Do not require prey death, complete emptying or a universal natural
    trigger. Toxicyst discharge traitmech:000685 explicitly leaves haptocyst terminology
    unresolved; this organelle-specific record does not settle whether historical
    toxicyst umbrellas include haptocysts. Do not equate haptocysts with kinetocysts,
    trichocysts or mucocysts, or assert homology or organism-level disjointness. No
    exact synonyms or xrefs are assigned.
  posed_by: codex
  posed_date: '2026-10-10'
- discussion_id: haptocyst-discharge-provenance-and-mechanism
  prompt: Verify natural exemplars and separate release from attachment and ingestion.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: Experimental culture provenance and current strain-level taxonomy remain
    unchecked; no canonical examples are assigned. The two citations support different
    claims and are not replicate discharge assays. Tentacular ultrastructure does
    not establish a conserved protein mechanism, toxin composition or signaling pathway.
    A future graph needs direct perturbation evidence and taxon-paired accessions,
    separating assembly, triggering, extrusion, attachment and ingestion. Mechanism
    is deferred, not claimed absent. Sequence features alone would not establish any
    of these causal transitions.
  posed_by: codex
  posed_date: '2026-10-10'
curation_history:
- timestamp: '2026-10-10T01:50:07Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added haptocyst discharge with two primary DOI sources and directly checked
    abstract/Summary snippets, distinguishing discharge evidence from organelle identity
    and attachment. Ignored-and-hidden main/worktree/open-PR checks support 000686
    and v562 block 1063900-1063999. Exocytosis hierarchy, natural exemplars and protein
    mechanisms remain unresolved. Existing records unchanged. Timestamp records the
    observed UTC curation decision.
  llm_assisted: true