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cytogamy

traitmech:000623 · CLASS · PROPOSED

A sexual-reproduction phenotype in which a paired cell self-fertilizes by fusion of its own gametic nuclei without exchanging gametic nuclei with its partner.

Trait evidence (3)

  • DOI:10.1017/S0016672300010740
    Cytogamy is a process of internal self-fertilization in animals which appear to conjugate, but which in fact do not exchange nuclei

    Nobili and Luporini (1967), PMID:4964874, p.39 parenthetical before the Wichterman citation, checked in the typeset PDF. This directly read definition supports paired-cell internal self-fertilization without nuclear exchange. The surrounding Results and Table 2 offer cytogamy as an explanation for three mating-type outlier clones; they do not directly demonstrate cytogamy in those clones. The paper's primary experiments concern autogamy in Euplotes minuta. Do not count this terminology passage as independent experimental replication or turn its proposed explanation into a canonical taxon example. The cited 1940 original was not read beyond bibliographic metadata.

  • DOI:10.1111/j.1550-7408.1958.tb02567.x
    In fact, the conjugation process seems to be one of double autogamy (cytogamy), rather than of reciprocal gametic interchange.

    Diller (1958), scientific abstract directly read on the Wiley publisher page. The qualifier seems is retained. Paired Paramecium polycaryum cultures collected at Annamalainagar, South India, showed nuclear behavior resembling autogamy in singles. Breakdown of the paroral cones permitting micronuclear passage was not observed; this is not a genetic exclusion of exchange. The abstract also describes fertilization and postzygotic nuclear reorganization. Double autogamy is source-attributed terminology, not equivalence with our unpaired-cell autogamy class. Full text, actual figures and tables were not inspected; the tentative observation is not an unqualified canonical example.

  • DOI:10.1093/genetics/91.4.657
    cytogamy generates exconjugant clones that derive their entire genetic information from a single meiotic product of their cytoplasmic parent.

    Orias and Hamilton (1979), PMID:17248904, PMC1216858, scientific abstract clause after By analogy to Paramecium, directly checked in Europe PMC core metadata and NCBI PMC EFetch front-matter XML. The abstract reports hyperosmotic-shock-induced cytogamy in tested Tetrahymena thermophila strains and high fertility in most progeny. Its whole-genome-homozygote interpretation is source-specific, not a universal definition requirement or a genome-sequencing result established here. Other rare transmission abnormalities were not characterized in that abstract. The full text, Methods, actual figures and tables remain unread: PMC EFetch withholds body XML, and attempted public PDF retrieval did not yield a readable PDF. Strain provenance is unresolved; no natural canonical example or protein-level causal mechanism is inferred from this abstract.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1017/S0016672300010740

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.

Distinguish paired-cell self-fertilization from unpaired autogamy.

CURATION TODO OPEN cytogamy-scope-and-hierarchy · raised by codex · 2026-10-05

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.

Pairing with internal gametic-nuclear fusion and no gametic-nuclear exchange distinguishes this class from ordinary conjugation with exchange and from operationally unpaired autogamy traitmech:000622. Diller (1958) calls the tentative observation double autogamy; preserve that broader source usage without silently making cytogamy a child or exact synonym of the unpaired class. This is not all selfing or a literal mating locus. No universal hyperosmotic trigger, whole-genome homozygosity, nuclear count or inability to outcross is imposed. Do not infer species-level disjointness between reproductive modes. The parent gap is resolved by automixis traitmech:000625, whose single-meiotic-cell nuclear origin includes this operational scope. The broader terminology and mapping questions keep this discussion OPEN. Verify external equivalences and synonym scope before adding mappings.

Resolve original cytology, strain provenance and molecular mechanisms.

CURATION TODO OPEN cytogamy-mechanism-and-provenance · raised by codex · 2026-10-05

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.

The 1967 definitional passage is not a direct cytogamy experiment, the 1958 observation is tentative, and the 1979 evidence here is limited to its scientific abstract. Retrieve the original primary study DOI:10.1002/jmor.1050660303 (Wichterman, 1940) and the remaining experimental material before stronger cytological or natural-strain claims. That 1940 DOI is a metadata-verified research lead, not counted trait evidence. No canonical example is assigned from unresolved provenance or tentative marker explanations. Induced transmission outcomes do not identify a molecular causal pathway; graphs and protein accessions remain deferred. Retain actual snippet-resolver outcomes separately from direct source checks.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added cytogamy with three DOI-backed snippets and paired-cell self-fertilization scope. Ignored-and-hidden novelty/allocation checks found no exact record or collision. Reserved METPO:1057600 in v499 under phenotype, not operational unpaired autogamy. Preserved tentative observations, induced-system and source-access limits; deferred canonical examples, mappings and causal graphs.

  2. · QUALIFIED_TRAIT_SCOPE · codex

    Addressed #1717: replaced without reciprocal exchange with no gametic-nuclear exchange with the partner, excluding one-way transfer as well. Used an individual paired-cell formulation without requiring the same outcome in both partners. Preserved all evidence, source qualifiers and the phenotype parent.

  3. · RESOLVED_PARENT_GAP · codex

    Reparented below automixis traitmech:000625 and documented the resolved parent gap while retaining other open terminology and mapping questions. Preserved definition, evidence, examples and prior history. v501 carries the existing proposed METPO ID with this hierarchy; earlier standalone templates remain historical.