pseudohyphal growth

traitmech:000653 · CLASS · PROPOSED

A morphological phenotype in which elongated budding yeast cells remain attached in chains with constrictions at the junctions between cells.

Trait evidence (2)

DOI:10.1590/S1517-83822013005000056
pseudohyphae formed branched chains of elongated blastoconidial cells retaining constrictions at the septal junctions

Staniszewska et al. (2013), PMID:24516422, PMC3910194, Results subsection Pseudohyphae. Full-text XML, strain/culture Methods, Table 1 and actual Figure 4 were inspected. Clinical isolate 82 forms pseudohyphae mixed with true hyphae after six hours in serum; later hyphal predominance is not a contradictory same-time observation. The quote is from Results, not the abstract. Numerical morphology indices and serum induction conditions are study-specific, not universal trait thresholds.
DOI:10.1016/0092-8674(92)90079-r
Cells become long and thin and form pseudohyphae that grow away from the colony and invade the agar medium.

Gimeno et al. (1992), PMID:1547504, scientific abstract directly retrieved through Europe PMC. Diploid Saccharomyces cerevisiae under nitrogen starvation changes morphology and budding pattern. The abstract also reports RAS2, SHR3 and RSR1/BUD1 perturbations. Full text and figures were not verified. Diploidy, nitrogen starvation and agar invasion describe this study, not necessary conditions for every pseudohyphal yeast.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1590/S1517-83822013005000056

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.

Candida albicans NCBITaxon:5476 DOI:10.1590/S1517-83822013005000056 Wild-type clinical bloodstream isolate 82, cultured in undiluted human serum for six hours at 37 C. Results and Figure 4A,C show pseudohyphae in a mixed population, not every cell or culture stage. Table 1 and Methods identify its clinical origin separately from the engineered comparison strains. This is an in-vitro morphology observation, not proof of pseudohyphae in the patient's bloodstream. NCBI Taxonomy resolves the species identifier and label.

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 yeast growth-form parent and exact external mappings.

CURATION TODO OPEN pseudohyphal-growth-scope-and-hierarchy · raised by codex · 2026-10-06

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. Mycelial growth traitmech:000074 is explicitly bacterial. Filament shaped METPO:1000674 has a broad hypha-like description but is classified under individual cell shape METPO:1000666; this record denotes attached budding-cell chains, not merely an elongated cell. Colony morphology METPO:1007062 concerns macroscopic colonies, not this microscopic growth form. Obsolete cell arrangement METPO:1000046 is not an active parent. Do not equate pseudohyphae with uninterrupted true hyphae, disordered aggregation, or every filamentous form. No exact synonym or xref is asserted. Different forms may coexist in one culture; this is not organism-level disjointness.

Resolve organism-specific morphogenesis mechanisms before graphing.

KNOWLEDGE GAP OPEN pseudohyphal-growth-mechanism-scope · raised by codex · 2026-10-06

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.

A causal graph is deferred pending full perturbation and protein-accession review, not because mechanisms are unknown. Do not transfer the 1992 budding-pattern or ploidy constraints to all yeasts, or treat the Candida comparison mutants as natural canonical examples. Gene possession alone does not establish pseudohyphal growth. Serum exposure, branching, agar invasion, numerical aspect-ratio cutoffs and virulence are not universal requirements. The 2013 study's bloodstream pathogenesis discussion does not directly demonstrate a pseudohypha-specific virulence mechanism. Additional Saccharomyces examples need direct strain-provenance review.

Curation history

2026-10-06T23:54:28Z · MINTED_TRAITMECH_ID · codex
Added pseudohyphal growth with two DOI-backed snippets, a condition-qualified clinical-isolate example, and explicit growth-form and mechanism limits. Ignored-and-hidden novelty searches and structured METPO review found no exact record. Reserved METPO:1060600 in v529; existing records unchanged.

Recorded curation sessions

2026-10-06T23:56:53Z · codex
- CREATE — Add evidence-backed pseudohyphal growth
  Created traitmech:000653 with DOI:10.1590/S1517-83822013005000056 and DOI:10.1016/0092-8674(92)90079-r, two directly checked snippets, and a condition-qualified Candida albicans clinical-isolate example resolved as NCBITaxon:5476. Ignored-and-hidden novelty searches and a fresh structured METPO frontier audit found no exact record. Added two scope/mechanism discussions and a v529 proposal reserving METPO:1060600. Existing records remain unchanged. The guarded writer dry run and 20 focused tests passed; corpus validation, generated artifacts and PR review remain pending at this event.
Read this curation session