ballistospore discharge

traitmech:000661 · CLASS · PROPOSED

A physiological phenotype in which a fungus forcibly discharges spores through coalescence of Buller's drop with liquid on the spore surface.

Trait evidence (3)

DOI:10.1371/journal.pone.0004163
At the moment of fusion, Buller's drop snaps from the hilar appendix onto the adjacent spore surface.

Stolze-Rybczynski et al. (2009), PMID:19129912, PMC2612744; Introduction, first paragraph, directly retrieved as publisher HTML and Europe PMC full-text XML. Abstract, Introduction, Results and Discussion, Table 1 and Methods were read. Seven basidiomycete species were analyzed by high-speed video; the yeast Sporobolomyces salmonicolor NPM01 had a measured mean launch speed of 1.42 +/- 0.12 m/s (s.e.m., six launches). Its 0.54 +/- 0.04 mm flight range is calculated, not a directly measured range. Drop geometry and flight range vary; a prominent lens-shaped adaxial drop is not universal. Figure captions were read, but image retrieval failed; actual figures, videos and supplements were not inspected.
DOI:10.1371/journal.pone.0105147
Ballistospores can be produced either asexually (ballistoconidia) or sexually (basidiospores).

Ianiri et al. (2014), PMID:25148260, PMC4141788; Introduction directly retrieved as full-text XML. This quotation supports terminology, not a new comparison of sexual and asexual development. Scientific abstract, strain table, mirror-assay Methods, initial mutant-screen Results and Discussion were also read. Of 18 mirror mutants, 17 had absent or reduced spore production; GI277 still formed abundant ballistospores but failed to release them. A failed mirror assay alone thus does not distinguish formation from discharge. PHS1 results concern delayed formation and broader cellular defects, not a demonstrated universal release motor. Actual figures, supplements and independent IAM 13481 provenance were not inspected; no canonical example is inferred from these mutants.
DOI:10.1242/jeb.029975
The fusion of the droplet onto the spore creates a momentum that propels the spore forward.

Noblin, Yang and Dumais (2009), PMID:19684219; scientific abstract retrieved directly through Europe PMC. The study reports high-speed observations in Auricularia auricula and Sporobolomyces yeasts, mechanical analysis and calibrated microcantilever measurements of detachment work. The artificial validation system is not a fungal exemplar. Predicted and observed velocities are distinct quantities. Full text, figures, supplements and strain provenance were not inspected; the abstract is not a complete mechanistic audit.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1371/journal.pone.0004163

Parent traits (1)

phenotype METPO:1000059

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.

Sporobolomyces salmonicolor NCBITaxon:5005 DOI:10.1371/journal.pone.0004163 Strain NPM01. Table 1 reports high-speed-video launch measurements from six spores, with mean initial speed 1.42 +/- 0.12 m/s (s.e.m.); the listed flight distance is modeled, not directly measured. Organisms and culture methods at https://doi.org/10.1371/journal.pone.0004163 identify NPM01 as isolated from a contaminated manufacturing facility and report spore formation on potato dextrose agar within 24 h. That primary provenance passage was read directly; no engineered-strain origin is inferred. NCBI Taxonomy resolves the species ID and label. This example concerns NPM01 under the reported conditions, not every strain or life stage.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Review dispersal hierarchy without equating formation and discharge.

CURATION TODO OPEN ballistospore-discharge-scope-and-hierarchy · raised by codex · 2026-10-07

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.

Use phenotype METPO:1000059. The sporulation and spore-forming records METPO:1000870 and METPO:1000871 concern endospores. Fungal conidiation traitmech:000657 concerns production of asexual propagules, whereas ballistospores include sexual and asexual forms and formation can persist without release. Discharge is also distinct from passive shedding, later wind transport and pressure-driven ascospore or sporangium ejection. Motility METPO:1000701 emphasizes independent locomotion; a closer dispersal parent and process-versus-phenotype mappings need review. Ballistospore and ballistoconidium name cells, not exact synonyms of this disposition; no exact synonyms or xrefs are asserted. Do not require a particular speed, distance, fruiting body or asexual developmental mode.

Keep measured discharge, formation defects and physical models distinct.

KNOWLEDGE GAP OPEN ballistospore-discharge-mechanism-and-readouts · raised by codex · 2026-10-07

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 cited studies support a surface-tension mechanism, not an unknown-mechanism claim. A causal graph is deferred until the full mechanical study and supplementary observations are inspected and the repository's protein-required MECHANISTIC graph convention is reconciled with a physical coalescence mechanism. Do not invent a protein motor or label a physical causal model NONMECHANISTIC merely to pass the audit. PHS1 possession or expression does not establish discharge; the 2014 formation-defect experiments do not isolate a universal ejection pathway. Negative mirror transfer can reflect impaired production, release or subsequent growth. The 2017 study at https://pmc.ncbi.nlm.nih.gov/articles/PMC5550963/ remains an unread research lead: PMC returned a challenge and two XML requests failed. It is not counted as verified evidence.

Curation history

2026-10-07T08:42:05Z · MINTED_TRAITMECH_ID · codex
Added ballistospore discharge with three directly checked DOI-backed snippets, a provenance-qualified NPM01 example and explicit formation/discharge and measured/modeled distinctions. Ignored-and-hidden searches and structured METPO review found no exact record. Reserved METPO:1061400 in v537; existing records unchanged. Physical mechanism evidence is retained; graph formalization is deferred.
2026-10-07T09:12:00Z · CORRECTED_EVIDENCE_SNIPPET · codex
Replaced the subjectless Results fragment with a complete, exact Introduction sentence describing Buller's-drop fusion (#1781). Updated the section locator; retained the original minting event and all experimental and source-access qualifications.

Recorded curation sessions

2026-10-07T08:44:44Z · codex
- CREATE — Add ballistospore discharge with source-bounded physical and developmental evidence
  Added PROPOSED traitmech:000661 under phenotype METPO:1000059 using DOI:10.1371/journal.pone.0004163, DOI:10.1371/journal.pone.0105147 and DOI:10.1242/jeb.029975. All three snippets were matched to directly retrieved source text. Retained a provenance-qualified Sporobolomyces salmonicolor NPM01 example, separated measured velocity from modeled range and formation from discharge, and documented source access limits and deferred graph formalization. Ignored-and-hidden searches and structured METPO/seed review found no exact prior trait. Reserved METPO:1061400 in proposal v537. Writer dry run and 20 focused tests passed before application; broader validation and generated-artifact review remain subsequent steps. Existing traits, including protected spore germination, were not edited.
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2026-10-07T09:12:32Z · codex
- EDIT — Replace subjectless discharge snippet with a complete source sentence
  Corrected issue #1781 from PR #1780. Replaced the first DOI:10.1371/journal.pone.0004163 snippet with a 21-word complete Introduction sentence, exact-matched to the directly retrieved XML. Updated its section locator and appended CORRECTED_EVIDENCE_SNIPPET without altering the initial minting event. All other evidence, definition, hierarchy, example and discussion content remains unchanged. The guarded writer now accepts only the exact initial or corrected record; 23 focused tests and dry run passed before application. Initial full regression suite passed 3062 tests before this correction; post-correction validation follows.
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2026-10-07T09:12:48Z · codex
- AUDIT — Correct replacement-snippet word count in history
  The EDIT history record 2026-10-07T091232Z-codex-0bfe38.yaml mistakenly says the replacement has 21 words. The exact Introduction sentence has 17 whitespace-delimited words, as confirmed by the source comparison immediately before application. The quote itself, source match, record and test results are unchanged. This append-only correction supersedes only that numerical history claim.
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