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cyanobacterial false branching

traitmech:000675 · CLASS · PROPOSED

A morphological phenotype in which a filamentous cyanobacterium forms an apparent branch by trichome-bundle partitioning or lateral trichome protrusion without generating a branch-point cell connecting at least three neighboring cells at that junction.

Trait evidence (3)

  • DOI:10.1127/algol_stud/83/1996/303
    Two basic types of false branching (by bundle partitioning and by lateral trichome protrusion)

    Golubic et al. (1996), scientific abstract directly read on the publisher page https://www.schweizerbart.de/papers/algol_stud/detail/83/91090/Developmental_aspects_of_branching_in_filamentous_. Crossref confirms DOI, title and authors. The developmental analysis distinguishes false from true branching by branch-point cells contacting at least three neighbors. This terminology authority supports both listed modes, not only sheath rupture following necridium formation. Full article and figures were not inspected; no new experimental replication or universal molecular mechanism is inferred from the abstract.

  • DOI:10.5507/fot.2021.017
    initiation of branching after disintegrating of sheath at the site of a necridia cell

    Tawong et al. (2022), Figure 1k caption, article page 82 in https://fottea.czechphycology.cz/pdfs/fot/2022/01/05.pdf (PDF page 5); actual Figure 1 panels and Methods/Results read. Source grammar is retained. Results page 81 points to Figs 2e-k for false branching, but the microscopy is Figure 1e-k; Figure 2 is phylogeny. NUACC05/06 show single and binary false branches associated with separation, heterocytes and loop rupture. The captioned necridium route is not required for every branch or for bundle partitioning.

  • DOI:10.1111/jpy.13256
    False branches developed adjacent to necridic cells or heterocytes, or by separation of vegetative cells at compression folds in the trichome.

    Masumoto and Sanders (2022), scientific abstract directly read at https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13256. Microscopy of lichen cyanobionts reports multiple branching modes within a strain, so false and true branching are not disjoint organism-level traits. Secondary attachment of freed apical segments is separately described as pseudo-branching; that term is not imported as an exact synonym. Full text, figures and supplements were not inspected.

Provenance

Identifier source
TraitMech local identifier
Definition source
DOI:10.1127/algol_stud/83/1996/303

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.

  • Scytonema foetidum NCBITaxon:2929979 DOI:10.5507/fot.2021.017 Example restricted to false-branched filaments of natural isolate NUACC06, not every cell or stage. Methods describe single-filament isolation from wet Khek River bank soil, Thailand, April 2019, followed by CT/2 liquid culture at 25 degrees C with a 12:12 light-dark cycle. Live NCBI Taxonomy efetch https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=taxonomy&id=2929979 confirms this current species name, rank species and NUACC06 type material; it is not a strain-rank accession. Taxonomy supports identity, not independent phenotype evidence.

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 closer multicellular morphology parent and branching terminology.

CURATION TODO OPEN false-branching-scope · raised by codex · 2026-10-08

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 below quality METPO:1000188. Branched shaped METPO:1000687 concerns lateral branches in cell shape, not necessarily this arrangement of trichomes; no subclass or equivalence is asserted. The Golubic 1996 definition authority includes bundle partitioning as well as lateral protrusion. The Scytonema example demonstrates the latter and must not narrow the whole class. Necridium formation traitmech:000674 describes a separation cell, not all false branches. Hormogonium formation traitmech:000651 describes dispersal filaments, not the branching topology. Obsolete cell-arrangement METPO terms redirect to flagellar arrangement, which is not a suitable parent here. No exact synonyms, xrefs, SSSOM mappings or organism-level disjointness are asserted; historical pseudo-branch usages need review. The label is qualified as cyanobacterial false branching because the directly read English scientific abstract of Nesterenko et al. (1980), PMID:6782438 (https://pubmed.ncbi.nlm.nih.gov/6782438/), uses false branching for growth of separated cell ends in the organism historically named Brevibacterium helvolum ATCC 19239. That distinct usage is not evidence for cyanobacterial trichome development. Its full text and modern taxonomic identity were not inspected. No unqualified exact synonym or cross-taxon mechanism is asserted. See review issue #1821.

Resolve mechanisms separately for each developmental mode.

KNOWLEDGE GAP OPEN false-branching-mechanism · raised by codex · 2026-10-08

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 inspected microscopy supports a phenotype and cellular developmental routes, not an accession-resolved protein mechanism. Taxonomic sequence markers do not establish causality. Do not require necridia, heterocytes, a fixed branch count, one division plane, a universal trigger or a fitness benefit. No causal graph is proposed pending direct mechanistic evidence and verified protein examples; a mechanism is not claimed biologically absent.

Curation history

  1. · MINTED_TRAITMECH_ID · codex

    Added cyanobacterial false branching with three DOI sources, verbatim snippets and a source-qualified NUACC06 example. Ignored-and-hidden searches of current main, worktrees and complete open-PR curation snapshots support 000675 and v551 block 1062800-1062899. Preserved both developmental modes, local branch-point scope and uncertainty about protein mechanisms. Existing traits unchanged. Timestamp is observed UTC curation time.

  2. · QUALIFY_TRAIT_LABEL · codex

    Addressed #1821: qualified the label to its cyanobacterial scope after directly checking the non-cyanobacterial usage in PMID:6782438. Preserved definition, evidence, example, identifier, proposal block and original curation event. Added source-qualified terminology discussion without an unqualified exact synonym.

Recorded curation sessions

  • · codex
    • CREATE — Add source-qualified cyanobacterial false branching

      Mint traitmech:000675 and reserve v551 METPO:1062800-1062899. Three DOI references with verbatim snippets support both developmental modes and a natural NUACC06 example at verified species rank. Defer closer-parent and protein-mechanism questions; preserve existing records.

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  • · codex
    • EDIT — Qualify cyanobacterial false branching after adversarial review

      Address #1821 after directly reading PMID:6782438: qualify the label, document the non-cyanobacterial terminology boundary, and keep the original definition, evidence, example and ID reservation. Preserve 2026-10-08T063135Z-codex-0b8330.yaml and the original per-record event unchanged; append a correction event and regenerate artifacts.

    Read this curation session