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tetrapolar mating system

traitmech:000615 · CLASS · PROPOSED

A fungal mating phenotype in which compatibility between partners is governed by two independently segregating mating-type factors and requires different specificities at both factors.

Trait evidence (2)

  • DOI:10.1371/journal.pgen.1002528
    None of these MAT recombinant progeny mated with either parent, further confirming that C. amylolentus possesses a tetrapolar mating system

    Findley et al. (2012), PMID:22359516, PMC3280970. Exact Results s2g clause, not an abstract quote. The preceding sentences report interfertility of complementary recombinants; parent sterility alone is insufficient. Introduction defines the two unlinked factors and differences at both. Actual Figures 8/9 were inspected: sexual structures and the mating matrix support the functional phenotype. Figure 9A is a conceptual model, not an observed equal-ratio result. Results s2b/s2e, direct prose of s2f/s2g and Methods s4a/s4m were read. Mixed F1 progeny include blastospores; frequent infertility and biased mating types make this a modified tetrapolar cycle. Complete Text S1 was text-extracted, not page-rendered: filamentation is not successful mating. Its description of F1S2 #16 as sterile must not override s2g's successful crosses with some partners. Tables 1/2, other figures and other supplements remain uninspected. Physical MAT separation alone in T. wingfieldii does not establish its reproductive phenotype.

  • DOI:10.1534/genetics.115.177717
    independent assortment of MAT alleles was observed in the meiotic progeny of a test cross.

    Maia et al. (2015), PMID:26178967, PMC4566278. Exact scientific abstract clause, directly retrieved from Europe PMC core metadata and checked against NCBI efetch front matter. Leucosporidium scottii has physically unlinked HD and P/R regions; the reported meiotic segregation supports functional tetrapolarity independently of sequence annotation. Natural population linkage disequilibrium does not contradict the test-cross result. The abstract reports fertile progeny of four mating types but approximately two thirds nonhaploid; do not impose universal haploidy or equal ratios. Full-text XML/PDF endpoints failed with HTTP 500/403 and NCBI returned no body. Methods, figures, supplements and natural strain provenance remain uninspected; no canonical example is inferred.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1371/journal.pgen.1002528

Parent traits (1)

kg-microbe context

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

Canonical examples (1)

Organisms cited as exemplars of this trait. Taxon ids are NCBITaxon and link out to the NCBI record.

  • Cryptococcus amylolentus NCBITaxon:104669 DOI:10.1371/journal.pgen.1002528 Qualified to the CBS6039 x CBS6273 cross, not every strain or laboratory-derived progeny. Natural provenance: Methods Strains and media at https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1002528 reports both isolates from insect frass in South Africa. Mating used V8 pH 5 in the dark at 24 C; actual Figure 8 shows two-week sexual structures and Figure 9 compares complementary mating combinations. Recombinant fertility, not hyphae alone, supports the modified tetrapolar classification. NCBI taxonomy 104669 resolves to this species on 2026-10-05.

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 mating compatibility separate from partner dependence and MAT inventory.

CURATION TODO OPEN tetrapolar-mating-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.

This is a functional compatibility phenotype, not possession of two loci or exactly four mating types throughout a species. Factors can be multiallelic; different specificities are necessary, not a guarantee of fertile progeny in every cross. Findley describes the observed C. amylolentus cycle as heterothallic, but that example does not make the broader compatibility axis equivalent to obligatory separate-partner dependence in traitmech:000610. The latter already separates nuclear recognition from organism-level self-fertility. Use released phenotype METPO:1000059 in both record and proposal rather than infer universal self-sterility. Do not assert disjointness with homothallism, fixed segregation ratios, universal A/B naming or identical recognition architectures. Resolve bifactorial terminology and external mappings before adding synonyms or xrefs. PHYSIOLOGY is a filesystem category, not a narrower ontology parent.

Resolve native mechanisms and unread experiments before extending the graph.

CURATION TODO OPEN tetrapolar-mating-mechanism-and-readouts · 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.

Complete the unread Maia full text and Findley tables and supplements before finer mechanistic or strain claims. Distinguish MAT-locus separation, genetic segregation, compatibility, filamentation and fertile sexual progeny. An unsuccessful cross alone does not establish trait absence; source-specific sterility can be relative to particular partners. Resolve native protein accessions and experimentally tested dependencies before causal edges. No NONMECHANISTIC graph is used to bypass protein grounding. Manual full-text matches do not replace the abstract resolver's actual verdict.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added tetrapolar mating system with two independent DOI-backed sources and verbatim snippets, a qualified natural CBS6039 x CBS6273 example and verified NCBI taxonomy. Kept mating evidence distinct from MAT sequence inventory, universal fertility and partner dependence. Ignored-and-hidden novelty and allocation searches found no exact record or ID collision. Reserved METPO:1056900 in v492 under released phenotype. Deferred lexical mappings, protein mechanisms and explicitly unread source material.