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heterokaryon incompatibility

traitmech:000606 · CLASS · PROPOSED

A fungal phenotype in which postfusion nonself recognition restricts the establishment or growth of viable vegetative heterokaryons.

Trait evidence (3)

  • DOI:10.1099/mic.0.032284-0
    Incompatible heterokaryons show a macroscopic phenotype of slow growth and diminished conidiation, and a microscopic phenotype of hyphal compartmentation and cell death.

    Hutchison et al. (2009), PMID:19696111. The directly retrieved Europe PMC abstract and publisher abstract identify nonself recognition during fusion between strains differing at het loci, with restricted growth and localized cell death. This supports postfusion heterokaryon incompatibility, not failure to approach or fuse. The study combines transcriptional profiling with functional analysis of het-c pin-c incompatibility in Neurospora crassa. Transcript associations do not establish causal edges; the abstract reports that tested caspase and AIF homologues were not required. Full text, figures and supplements were not retrieved, so no detailed assay or protein-dependency claim beyond the abstract is asserted.

  • DOI:10.1016/s1087-1845(03)00086-0
    Hyphal fusion cells in compatible self-pairings and hyphal cells in het-c compatible transformants were not compartmentalized and rarely showed TUNEL-positive nuclei.

    Marek et al. (2003), PMID:14516765; snippet exact-matched to the directly retrieved Europe PMC abstract. Incompatible Neurospora crassa pairings differing at mat, het-c and het-6 were compared with compatible self-pairings; separate transformant experiments tested incompatible het-c alleles. The abstract reports septal compartmentation and nuclear DNA degradation in incompatible cells, contrasted with the quoted controls. TUNEL and apoptosis-like morphology do not identify a conserved metazoan apoptosis pathway. Death also occurred in older hyphae, so death alone is not specific for this trait. Full text, figures, supplements and original strain provenance were not inspected; no natural canonical exemplar is inferred from the transformed assay.

  • DOI:10.3852/mycologia.98.1.43
    While clearly forming barrages in mycelial interactions, paired strains with different alleles at vic4 formed stable heterokaryons.

    2006 primary study, PMID:16800303; snippet exact-matched to the directly retrieved Europe PMC abstract. Hygromycin B- and benomyl-resistance forcing markers were used in Cryphonectria parasitica pairings. Differences at vic1, vic2, vic3, vic6 or vic7, but not vic4, produced heterokaryon incompatibility readouts of slow growth or abnormal morphology. The vic4 counterexample separates barrage formation from this trait; the abstract treats heterokaryon incompatibility as a component of a broader vegetative incompatibility system. Vegetative incompatibility is therefore not asserted as an exact synonym. Full text, figures, supplements and marker-strain provenance were not inspected. The DOI and any publisher alias identify one study, not independent replications.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1099/mic.0.032284-0

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.

Keep postfusion incompatibility distinct from broader vegetative barriers.

CURATION TODO OPEN heterokaryon-incompatibility-scope · raised by codex · 2026-10-04

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.

This organismal phenotype is not a het/vic locus, protein domain, sequence feature or individual pairing result. It requires nonself recognition, not merely slow growth or cell death. Barrage formation, prefusion avoidance, negative autotropism, sexual incompatibility and inability to fuse are not exact equivalents. Hyphal anastomosis can precede this response and is not an is-a parent. The definition does not require death of the whole colony, failure of every nonself pairing or a single conserved death pathway. The 2006 vic4 result prevents treating vegetative incompatibility as an unqualified exact synonym. Resolve organismal ontology equivalences at their issuing authorities before adding xrefs.

Read experimental details and resolve strain and protein anchors before enrichment.

CURATION TODO OPEN heterokaryon-incompatibility-mechanism-provenance · raised by codex · 2026-10-04

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.

Three primary abstracts support the phenotype and its boundary; full texts, figures and supplements remain unread. Separate natural pairing observations from transformants, forced heterokaryons and partial-diploid models when assessing canonical examples. Verify original strain provenance and current NCBI identities before adding taxon rows. Protein accessions, taxon pairing and native perturbation/rescue details must be checked before a causal graph is added. Transcript changes and TUNEL-positive nuclei are readouts, not proof of ROS necessity or canonical apoptosis. Do not use NONMECHANISTIC to hide unresolved protein mechanisms.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added heterokaryon incompatibility as a postfusion nonself recognition phenotype with three directly retrieved primary DOI-backed abstracts and exact snippets. Distinguished barrage formation and broader vegetative incompatibility; no exact synonyms, canonical examples or causal graph are asserted. Ignored-and-hidden repository searches and structured METPO review found no exact trait. Reserved METPO:1056000 in proposal v483 under released phenotype. Deferred unread full texts, strain provenance, protein grounding and external equivalences.