TraitMech

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rosette cell arrangement

traitmech:000652 · CLASS · PROPOSED

A morphological phenotype in which cells form multicellular clusters organized around a shared central region, with corresponding cell poles directed inward.

Trait evidence (2)

  • DOI:10.7554/eLife.41482
    all cells are oriented with their basal poles toward the rosette center and their apical flagella extending out from the rosette surface

    Wetzel et al. (2018), PMID:30556809, PMC6322860, first Results subsection; full-text XML and Figure 1 directly inspected. Wild-type Salpingoeca rosetta rosettes have organized polarity, unlike disordered clumps in the four Class C mutants. Methods identify wild type as SrEpac and use Algoriphagus-derived rosette-inducing factors. The three-cell minimum after vortexing is this study's scoring rule, not a universal definition. Clonal development rather than aggregation is specific to S. rosetta here. The Results quote is not the scientific abstract or editorial digest.

  • DOI:10.1128/jb.00064-19
    form multicellular rosettes by adhering to each other through the polar polysaccharide, or holdfast.

    Fiebig (2019), PMID:31010900, PMC6707911, Results subsection Holdfasts are prominent in the pellicle. Publisher HTML, growth/sampling/microscopy Methods, and Figure 4 were directly inspected. Static CB15 cultures form rosettes with holdfast-rich cores. The Results describe both radial and oblong rosettes; not every core is a single attachment point. Supplemental Figure S2's text was accessible but its image was not verified. Pellicle dependence on holdfast is not a universal rosette mechanism. The Discussion leaves the field relevance of thick Caulobacter pellicles unresolved; laboratory observations are not evidence that these structures occur in every habitat.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.7554/eLife.41482

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.

  • Salpingoeca rosetta NCBITaxon:946362 DOI:10.7554/eLife.41482 Wild-type SrEpac (ATCC PRA-390) in rosette-inducing-factor cultures, not every life stage. Natural-isolate provenance was checked in Levin and King's Experimental Procedures: https://doi.org/10.1016/j.cub.2013.08.061. SrEpac is isolate C, derived from Px1 by feeder replacement, antibiotic treatment and clonal isolation; Px1 derives from environmental rosette isolate ATCC 50818. It is not the EMS-mutagenized isolate B. The provenance citation is not counted as independent trait evidence. NCBI Taxonomy resolves the species ID 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 multicellular arrangement parent and exact external mappings.

CURATION TODO OPEN rosette-cell-arrangement-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. Cell shape METPO:1000666 describes an individual cell, while colony morphology METPO:1007062 and colony shape METPO:1007063 describe macroscopic colonies on solid medium. Neither is the genus of this microscopic multicellular arrangement. Obsolete cell arrangement METPO:1000046 is not a usable active parent. Star shaped METPO:1000685 is one cell with radiating projections; staphylococcus arrangement traitmech:000118 is an irregular coccal cluster. Holdfast traitmech:000184 is a polar adhesin phenotype, not a rosette, and biofilm formation traitmech:000053 does not define this arrangement. Co-occurrence is not organism-level disjointness. No unqualified synonym, external equivalence, perfect spherical symmetry, fixed cell count or single central attachment point is asserted. Irregular clumping alone is insufficient.

Keep organism-specific developmental and adhesion mechanisms separate.

KNOWLEDGE GAP OPEN rosette-cell-arrangement-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.

The two primary studies support a shared morphological description, not one homologous developmental program. Wetzel et al.'s exclusion of aggregation concerns S. rosetta rosettes, whereas Fiebig describes polar adhesion in Caulobacter. Do not require clonal division or a bacterial holdfast for all rosettes. A causal graph is deferred pending separate organism-scoped perturbation and accession reviews, not because mechanisms are unknown. Holdfast-associated genes or predicted glycosyltransferases alone do not establish the observed arrangement. Quantitative shear, growth and cell-number thresholds are assay-specific. Additional bacterial canonical examples require strain-provenance and taxon verification; the CB15 evidence is retained without an unverified taxon row.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added rosette cell arrangement with two DOI-backed Results snippets, a provenance-qualified S. rosetta example, and explicit arrangement/mechanism boundaries. Ignored-and-hidden novelty searches and structured METPO review found no exact record. Reserved METPO:1060500 in v528; existing records unchanged.

Recorded curation sessions

  • · codex
    • CREATE — Add evidence-backed rosette cell arrangement

      Added traitmech:000652 as PROPOSED MORPHOLOGY with DOI:10.7554/eLife.41482 and DOI:10.1128/jb.00064-19 Results snippets, a provenance-qualified Salpingoeca rosetta NCBITaxon:946362 example, and two OPEN scope/mechanism discussions. SrEpac provenance was directly checked in DOI:10.1016/j.cub.2013.08.061; this is not counted as independent trait evidence. Ignored-and-hidden novelty and identifier searches plus fresh seed, release/review, RDF and pinned-template audits found no exact record or collision. Reserved METPO:1060500 in v528. Writer dry run and 20 focused tests passed; full validation, artifact generation and PR review were pending at this event. No existing trait was edited.

    Read this curation session