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synnema formation

traitmech:000656 · CLASS · PROPOSED

A morphological phenotype in which fungal hyphae aggregate into an erect, stalk-like asexual reproductive structure, with conidiogenous elements borne from the stalk in its fertile form.

Trait evidence (3)

  • DOI:10.1016/j.simyco.2017.09.001
    Hyphae of stipe parallel, 2–2.5 μm wide, pale-brown, slightly thick-walled.

    Woudenberg et al. (2017), PMID:29158610, PMC5679026. Direct full-text Taxonomy, Cephalotrichum lignatile description; the snippet describes this species, not universal dimensions or pigmentation. Actual Figure 7D-F shows synnemata, G the stalk apex, and H-I conidiophores and conidiogenous cells. Methods describes microscopic structures from SNA cultures after 14 days at 25 C in darkness; Figure 7A-C instead shows colonies on OA, MEA and DG18. The paper also reports loosely attached stipe hyphae in C. domesticum, so tight fusion is not imposed on the class.

  • DOI:10.3390/ijms21186660
    deletion of the brlA gene blocked conidiation but not the formation of synnemata formed by aggregation of hyphal mycelia.

    Zetina-Serrano et al. (2020), PMID:32932988, PMC7555563, Introduction's summary of the authors' experiment. Direct Results 2.2.3 and actual Figure 4 were also inspected: after 30 days on apples at 25 C in darkness, the engineered Penicillium expansum brlA-null strain formed sporeless hyphal stalks lacking mature conidiophores; the wild-type strain formed conidiophores in coremia. This supports separating stalk formation from completed conidiation, not a universal BrlA requirement for synnemata. The mutant is qualified evidence, not a natural canonical example.

  • DOI:10.1099/00221287-87-2-292
    Coremia of Penicillium claviforme develop in three stages; primordium formation, elongation, and sporulation.

    Watkinson (1975), PMID:1141857, scientific abstract retrieved directly from Europe PMC. The publisher abstract agrees on the three stages but uses a colon where this indexed version has a semicolon. Only abstract-level developmental evidence is used; full text and figures were not inspected. Nutrient responses in this study do not define all synnemata. The historical species name is retained without a new taxon mapping or exact coremium/synnema synonym assertion.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1016/j.simyco.2017.09.001

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.

  • Cephalotrichum lignatile NCBITaxon:2041050 DOI:10.1016/j.simyco.2017.09.001 Ex-type culture CBS 209.63. The primary taxonomic description and Figure 7 directly document synnemata; microscopic descriptions use SNA after 14 days at 25 C in darkness. Specimen examined and Table 1 at https://pmc.ncbi.nlm.nih.gov/articles/PMC5679026/ identify Hennebert's 1959 isolate from timber in a cave at Han-sur-Lesse, Belgium. This is primary isolate provenance, not an inferred wild-type or GMO status. Synnemata production can vary with culture history; it is not asserted for every life stage or growth condition.

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 a fungal reproductive morphology parent and terminology.

CURATION TODO OPEN synnema-formation-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.

Retain phenotype METPO:1000059. Sporulation METPO:1000870 and spore forming METPO:1000871 explicitly concern bacterial endospores; mycelial growth traitmech:000074 explicitly concerns bacterial hyphae. Hyphal anastomosis traitmech:000605 requires cytoplasmic continuity, not mere bundling. Pseudohyphal growth traitmech:000653 concerns chains of budding yeast cells. None is an exact duplicate or appropriate parent. Zetina-Serrano uses coremia for conidiophore clusters and synnemata for sporeless hyphal stalks; Watkinson uses coremia across developmental stages. Do not force these usages into an exact synonym. No exact external mapping or organism-level disjointness is asserted.

Resolve stage-specific mechanisms before adding a causal graph.

KNOWLEDGE GAP OPEN synnema-formation-development-and-mechanism · 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 fertile-form qualifier preserves the documented sporeless synnemata of the brlA-null P. expansum strain. Formation does not require already mature conidiophores or conidia, a universal shape, size, color, spore wetness, growth medium or nutritional trigger. BrlA perturbation separates developmental stages in that experiment; it does not establish a universal stalk-formation gene or a mechanism in Cephalotrichum. Defer a causal graph pending organism-specific perturbations and accession-level review. Gene possession alone does not establish this phenotype. Use the 2017 paper's directly examined CBS 209.63 material, not older sequences attributed to CBS 159.66 that the authors identify as erroneous.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added synnema formation with three DOI-backed snippets, a qualified Cephalotrichum lignatile example and developmental scope boundaries. Ignored-and-hidden searches and structured METPO review found no exact record. Reserved METPO:1060900 in v532; existing records unchanged.

Recorded curation sessions

  • · codex
    • CREATE — Add evidence-backed synnema formation phenotype

      Minted traitmech:000656 with three DOI-backed snippets, a strain-qualified Cephalotrichum lignatile CBS 209.63 canonical example, and two open scope/mechanism discussions. Reserved METPO:1060900 in proposal v532. Distinguish stalk aggregation from completed conidiation and hyphal fusion. Existing records unchanged; causal graph deferred.

    Read this curation session