TraitMech

TraitMech › PHYSIOLOGY

unisexual reproduction

traitmech:000613 · CLASS · PROPOSED

A fungal phenotype enabling sexual or parasexual reproduction with genetic contribution from only one mating type.

Trait evidence (4)

  • DOI:10.1371/journal.pgen.1003688
    Sexual reproduction involves cells of either opposite (bisexual) or one (unisexual) mating type.

    Feretzaki and Heitman (2013), PMID:23966871, PMC3744442. Exact sentence of the directly retrieved scientific abstract (abstract1), not the separate Author Summary. Introduction s1 also includes Candida unisexual reproduction and helper-cell stimulation. Results s2g/s2h and Methods s4a/s4f were read in XML: reduced sporulation in Spo11/Ubc5 mutants is distinct from hyphal growth, and Ubc5's precise role remains unresolved. Do not universalize one diploidization route or timing. Actual figures, complete tables, supplements and other experimental sections remain uninspected; no protein-level dependency is asserted here. Species names follow the paper.

  • DOI:10.1038/nature03448
    Furthermore, fusion and meiosis can occur between non-isogenic alpha strains, enabling genetic exchange.

    Lin, Hull and Heitman (2005), PMID:15846346. Exact sentence from the scientific abstract directly retrieved through Europe PMC core metadata. The API uses the word alpha. Cryptococcus same-type partners need not be genetically identical: this supports outcrossing within a mating type, not obligatory clonal selfing. Diploidization and meiosis distinguish the reported fruiting from purely mitotic growth. Full text, methods, figures, supplements and natural strain provenance remain uninspected; no canonical example is inferred.

  • DOI:10.1038/nature08252
    could be induced to undergo chromosome loss to produce diploid cells, thereby completing a parasexual mating cycle

    Alby et al. (2009), PMID:19675652, PMC2866515. Exact main-text clause retrieved via NCBI PMC efetch after Europe PMC full-text failure, not an abstract quote. All main-text paragraphs and Methods Summary were read; Figures 3/4 and Supplementary Figure 7 were visually inspected. Marked opaque Candida a-a partners form tetraploids. Supplement pp. 6-7/15 reports sorbose-induced ploidy reduction, including near-diploid and intermediate progeny, not uniform restoration of euploidy. Bar1-deletion assays and helper-stimulated wild-type mating are distinct: opposite-type pheromone helpers need not contribute genomes. Other figures and supplement sections remain uninspected. Engineered or marked strains are not promoted to natural canonical examples.

  • DOI:10.1371/journal.pbio.1001653
    generates abundant hyphae, homozygous diploid intermediates, and haploid meiotic spores when grown on mating-inducing media all by itself.

    Ni et al. (2013), PMID:24058295, PMC3769227. Exact Results s2a clause, not an abstract quote; its subject is XL280alpha. Scientific abstract, author summary, Results s2a and Methods s4b were read directly in XML. Solo culture on V8 or filament agar followed by spore isolation supports selfing in this laboratory F1 derivative of B3501alpha and JEC20a. Natural ancestral isolates do not make XL280 a natural exemplar. The paper does not resolve cell fusion versus endoreplication into one obligatory route. Actual figures, supplements including Table S4, and other experimental sections remain uninspected. Aneuploidy and adaptive benefit are not defining requirements of the whole trait.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1371/journal.pgen.1003688

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 mating-type contribution distinct from selfing, helper cells and MAT inventory.

CURATION TODO OPEN unisexual-reproduction-scope-and-hierarchy · 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.

One mating type does not mean one strain: non-isogenic same-type partners can exchange genetic material. Solo selfing overlaps homothallism (traitmech:000609), but the whole class is not restricted to single-isolate self-fertility. It is not a subclass of parasexuality (traitmech:000607), because meiotic cycles are also included. Pheromone-producing opposite-type helper cells are not necessarily genetic contributors, so do not require their physical absence. Use released phenotype METPO:1000059 in both record and proposal; PHYSIOLOGY is only a filesystem category. MAT sequence content, population mating-type bias or hyphae alone do not establish reproductive completion. Do not require universal meiosis, spores, cell fusion, clonality or absence of outcrossing. Resolve context-dependent same-sex mating terminology and external phenotype/process mappings before adding synonyms or xrefs. The existing homothallism evidence note, citing DOI:10.5598/imafungus.2015.06.01.13, groups unisexual reproduction within a homothallism umbrella. That wording conflicts with interpreting the current single-isolate self-fertility definition as a universal superclass here. Our scope decision interprets the umbrella as including unisexual selfing, not as evidence that every same-type outcrossing partner is independently self-fertile. Preserve the older source attribution and retain phenotype while the operational and umbrella scopes await curator reconciliation; issue #1703 records this explicit distinction.

Resolve native examples and taxon-specific reproductive mechanisms before graphing.

CURATION TODO OPEN unisexual-reproduction-mechanism-and-examples · 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.

Complete unread primary experiments and supplements before expanding mechanistic claims. Keep solo meiosis, non-isogenic same-type fusion and parasexual chromosome loss separate. Hyphal growth, cell fusion, ploidy change and viable progeny are different readouts, not interchangeable proof of a completed cycle. XL280 is a laboratory-cross derivative; Candida deletion and marked strains also do not establish natural canonical provenance. Verify natural strains and current taxonomic authority before adding examples, and native protein accessions before causal edges. No graph or unverified taxon/protein CURIE is asserted. Manual full-text matching is not an abstract-resolver VERIFIED verdict.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added unisexual reproduction with four DOI-backed exact source snippets after scientific-abstract, full-text and selected Candida figure/supplement checks. Distinguished mating-type contribution from selfing and pheromone helpers; included meiotic and parasexual cycles. Ignored-and-hidden novelty searches and structured METPO review found no exact record. Reserved METPO:1056700 in v490 under released phenotype. Deferred natural canonical examples, lexical mappings and protein-resolved causal graphs.

  2. · CLARIFIED_HIERARCHY_SCOPE · codex

    Addressed adversarial review issue #1703 by explicitly naming the existing homothallism umbrella wording and distinguishing it from the operational single-isolate self-fertility definition. Retained phenotype parent, source attribution and open curator reconciliation.