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haptocyst discharge

traitmech:000686 · CLASS · PROPOSED

A physiological phenotype in which a microbial cell releases material from haptocysts to the cell exterior.

Trait evidence (2)

  • DOI:10.1515/znc-1984-7-821
    The fine structure of haptocysts, characteristic organelles of most suctorians, is described during the resting state and the discharge after contact with the prey.

    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.

  • DOI:10.1007/BF00331480
    By these haptocysts the tentacle is attached to the prey.

    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.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1515/znc-1984-7-821

Parent traits (1)

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Resolve the exocytosis placement and historical extrusome terminology.

CURATION TODO OPEN haptocyst-discharge-scope-and-parent · raised by codex · 2026-10-10

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

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.

Verify natural exemplars and separate release from attachment and ingestion.

KNOWLEDGE GAP OPEN haptocyst-discharge-provenance-and-mechanism · raised by codex · 2026-10-10

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

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.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    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.

Recorded curation sessions

  • · codex
    • CREATE — Add source-bounded haptocyst discharge phenotype

      Added PROPOSED traitmech:000686 with Benwitz 1984 DOI:10.1515/znc-1984-7-821 discharge evidence and Bardele and Grell 1967 DOI:10.1007/BF00331480 organelle identity and attachment evidence, using directly read abstract/Summary snippets. Distinguishes organelle-plasma-membrane continuity from predator-prey fusion. Leaves the exocytosis hierarchy, natural canonical exemplars and protein mechanism unresolved. Ignored-and-hidden searches across main, all 22 existing worktrees, CommunityMech and exact open PR heads support novelty and the v562 block METPO:1063900-1063999. The guarded writer validates before explicit apply; no existing trait was changed. No causal graph, xref, synonym, taxon or protein accession is asserted.

    Read this curation session