identifier: traitmech:000610
label: heterothallism
definition: A fungal phenotype in which sexual reproduction requires a separate, compatible
  mating partner.
definition_source: DOI:10.1038/nature07528
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1038/nature07528
  snippet: The species has a heterothallic breeding system; isolates of complementary
    mating types are required for sex to occur.
  notes: O'Gorman et al. (2009), PMID:19043401. Exact scientific-abstract sentence
    retrieved from Europe PMC core metadata; the publisher abstract was also read.
    Aspergillus fumigatus produced cleistothecia and ascospores, with recombination
    between mating type and DNA fingerprint markers in progeny from an Irish environmental
    subpopulation. This is observed sexual-cycle evidence, not an inference from MAT
    genes alone. Full methods, figures, supplements and individual isolate provenance
    remain uninspected; no canonical strain or universal compatibility is asserted.
    The historical teleomorph name in this abstract is not used as a current taxonomy
    mapping.
- reference: DOI:10.1534/genetics.111.136358
  snippet: Coexpression of pre-2 and ccg-4 in the mat A background leads to self-attraction
    and development of barren perithecia without ascospores.
  notes: Kim et al. (2012), PMID:22298702. Exact scientific-abstract sentence directly
    retrieved from Europe PMC core metadata. Neurospora crassa experiments distinguish
    receptor/pheromone identity from completion of sexual reproduction. The quoted
    engineered coexpression phenotype is not self-fertility; attraction and fruiting-body
    initiation alone are insufficient readouts. Forced heterokaryon experiments require
    mating-type genes in different nuclei for meiosis and sexual sporulation in this
    study, not a universal fungal architecture. Full text, figures, strain provenance
    and supplements remain uninspected after PMC access challenges and a full-text
    API error. This citation supports readout limits, not an independent natural canonical
    example or a protein-resolved causal graph.
- reference: DOI:10.1371/journal.pgen.1006981
  snippet: Heterothallic progeny can mate only with homothallic strains, and progeny
    also segregate 50% homothallic, 50% heterothallic.
  notes: 'Yun et al. (2017), PMID:28892488. Exact sentence of scientific abstract
    abstract1 in PMC5608430 full-text XML, distinct from the author summary. Chromocrea
    spinulosa includes self-fertile and partner-dependent strains: self-sterile here
    does not mean unable to reproduce sexually with a compatible partner. The stated
    compatibility and segregation are source-specific, not requirements for all heterothallic
    fungi. Strain/culture Methods and Conclusions were also read. Cs23 and Cs27 natural
    provenance, most experiments, actual figures and supplements remain unverified.
    Nuclear-level heterothallic recognition within a self-fertile organism is not
    organism-level partner dependence. No canonical example is inferred from unstable
    Cs27-derived MAT transformants or from reference-strain labels.'
discussions:
- discussion_id: heterothallism-trait-scope
  prompt: Keep partner dependence distinct from sterility and nuclear recognition.
  kind: CURATION_TODO
  status: OPEN
  rationale: This is an organism-level reproductive phenotype, not a sequence feature
    or MAT-gene inventory. It requires a compatible partner, not exactly two mating
    types throughout fungi or compatibility with every other isolate. Self-sterility
    alone can also denote general infertility; resolve lexical scope before adding
    exact synonyms or external xrefs. Homothallism, heterokaryosis, ploidy, hyphal
    fusion and parasexuality are not is-a parents. Nuclear recognition within a self-fertile
    individual does not establish partner dependence at the organism level. PHYSIOLOGY
    is a filesystem category, not an ontology parent. Do not infer absence from an
    unsuccessful cross under one set of culture conditions.
  posed_by: codex
  posed_date: '2026-10-04'
- discussion_id: heterothallism-examples-and-mechanism
  prompt: Verify natural isolates and complete-cycle evidence before expanding the
    record.
  kind: CURATION_TODO
  status: OPEN
  rationale: Read the uninspected methods, figures and supplements and resolve natural
    strain provenance and active taxonomy before adding canonical examples. Separate
    completed meiosis and sexual progeny from attraction, hyphal fusion, fruiting-body
    initiation and MAT sequence content. Resolve native protein accessions and experimental
    dependencies before adding mechanistic edges; do not use a NONMECHANISTIC graph
    to bypass unresolved grounding. Preserve actual abstract-resolver verdicts separately
    from manual source-section checks.
  posed_by: codex
  posed_date: '2026-10-04'
curation_history:
- timestamp: '2026-10-05T02:09:00Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added heterothallism with three primary DOI-backed sources and exact scientific-abstract
    snippets. Separated partner dependence from general infertility, MAT content and
    incomplete sexual readouts. Ignored-and-hidden novelty searches and structured
    METPO review found no exact record. Reserved METPO:1056400 in v487 under released
    phenotype. Deferred natural canonical examples, lexical mappings and protein-resolved
    graphs.
  llm_assisted: true