identifier: traitmech:000687
label: kinetocyst discharge
definition: A physiological phenotype in which a microbial cell releases material
  from kinetocysts to the cell exterior.
definition_source: DOI:10.1078/0932-4739-00847
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1078/0932-4739-00847
  snippet: By electron microscopy, we show evidence that the kinetocyst is an extrusive
    organelle that discharges its contents upon food capture.
  notes: Sakaguchi et al. 2002, scientific Abstract directly read on 2026-10-10 at
    https://www.researchgate.net/publication/222864147. Electron microscopy of Raphidiophrys
    contractilis supports release during food capture, with the posterior remaining
    cell-attached and the anterior directed toward prey. The proposed scaffold role
    is not demonstrated causality. Crossref identifies the 2002 publication; ResearchGate's
    date and automatically linked author profile are not used as authority. Publisher
    access returned 403; full Methods and figures were not inspected. No universal
    toxin, prey-killing requirement or trigger is inferred.
- reference: DOI:10.1515/znc-1976-3-418
  snippet: Freeze-fracture studies reveal that extrusive organelles displaying saltatory
    particle movements in centrohelidian axopod are attached to highly ordered domains
    within the plasma membrane.
  notes: Bardele 1976, PMID:134561. Scientific abstract and primary full-text OCR
    directly read on 2026-10-10 at https://www.researchgate.net/publication/22999924.
    The snippet supports organelle identity and membrane attachment, not discharge
    alone. Printed pp191-193 describe formaldehyde-fume-induced release in living
    whole mounts and negative-stained expelled jacket material. Methods name Acanthocystis
    erinaceoides and Raphidiophrys ambigua; this observation is not assigned here
    to just one species. The author interprets kinetocysts as compound motile mucocysts.
    Food-trapping and movement models remain hypotheses. PDF images were unavailable;
    no visual audit or OCR-normalized quotation is claimed. The article year is 1976,
    not the later upload date.
- reference: https://protistology.jp/journal/congress_ab/53th_kobe/Abstract%20Book%20Kobe2020
  snippet: In this study, we used Tetrahymena thermophila as food and examined the
    process of food capturing and kinetocyst discharge by electron microscopy.
  notes: Wan and Suzaki, JSP/KSOP joint meeting, 22-23 November 2020, O-BPA06/P-1A01,
    printed pp11-12 (PDF indices 10-11). Primary conference abstract, not a peer-reviewed
    full paper. Both pages were visually inspected on 2026-10-10. The snippet establishes
    assay context in Raphidiophrys contractilis, not the outcome alone. Following
    results describe stretched filamentous contents and expansion of the ring structure
    after discharge. Immuno-EM MVP localization suggests a prey-recognition role but
    does not establish causal necessity or a conserved release mechanism. Tetrahymena
    is prey here, not the kinetocyst-bearing organism.
discussions:
- discussion_id: kinetocyst-discharge-scope-and-parent
  prompt: Resolve historical mucocyst terminology and exocytosis placement.
  kind: CURATION_TODO
  status: OPEN
  rationale: Retain phenotype METPO:1000059 pending hierarchy review. Bardele 1976
    interprets kinetocysts as compound motile mucocysts; preserve that attribution
    rather than asserting separation from every historical mucocyst umbrella. Existing
    mucocyst discharge traitmech:000684 uses a membrane-fusion release definition
    supported in Tetrahymena and explicitly defers terminology reconciliation. Neither
    exact equivalence nor a mucocyst parent is established here. The fusion-pore differentia
    of exocytosis traitmech:000637 also needs class-wide scope review; placement is
    unresolved, not excluded. Possession, docking, axopodial movement or contraction,
    prey adhesion, ingestion and nonspecific cell lysis alone do not demonstrate discharge.
    Complete emptying, prey death and one universal trigger are not required. Historical
    conicyst organelle terminology does not automatically establish an exact phenotype
    synonym. No equivalence to haptocyst discharge traitmech:000686, homology, disjointness,
    exact synonyms or xrefs are asserted.
  posed_by: codex
  posed_date: '2026-10-10'
- discussion_id: kinetocyst-discharge-exemplars-and-mechanism
  prompt: Resolve assay-strain provenance and release-specific molecular evidence.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: 'No canonical examples are assigned: full primary assay Methods and their
    relation to the deposited natural culture need joint verification. The evidence
    items have different scopes, not three equivalent discharge replications. Organelle
    ultrastructure and protein localization alone do not establish a causal release
    pathway. Separate assembly, movement, triggering, extrusion, attachment and ingestion
    before adding graph edges. A protein mechanism needs direct functional evidence
    and taxon-paired accessions; sequence features alone cannot provide that support.
    Mechanism is deferred, not claimed absent.'
  posed_by: codex
  posed_date: '2026-10-10'
curation_history:
- timestamp: '2026-10-10T04:04:55Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added kinetocyst discharge with two primary DOI citations and a primary
    conference abstract, source-checked snippets and explicit access limits. Ignored-and-hidden
    main/worktree/open-PR reservation checks support 000687 and v563 block 1064000-1064099.
    Historical mucocyst scope, exocytosis placement, canonical exemplars and protein
    mechanism remain unresolved. Existing records unchanged. Timestamp records the
    observed UTC curation decision.
  llm_assisted: true