deep fiber

GO:0032123 · Cytoskeleton · Filament · Proposed

Inward projections of the cytoskeletal structures of the oral apparatus, which form a fiber that extends past the cytostome into the cytoplasm. [GO:0032123]

Synonyms: deep fibre

Part of: oral apparatus (GO:0031912); GO:0005856 — cytoskeleton (no local record)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Canonical examples

NCBITaxon:5911 Tetrahymena thermophila — Ciliate model covered by Frankel's Methods in Cell Biology review that supplied the GO deep-fiber definition. [DOI:10.1016/S0091-679X(08)61528-9]

Mechanism graphs

Deep fibers project through the oral apparatus (FUNCTION)

Deep fibers are cytoskeletal oral-apparatus substructures that form inward fibers extending past the cytostome.

Subject	Predicate	Object	Evidence
deep fiber	is part of	oral apparatus	`GO:0032123` GO:0032123 defines deep fibers as inward projections of the cytoskeletal structures of the oral apparatus.
deep fiber	extends past	cytostome	`GO:0032123` GO:0032123 defines deep fibers as oral-apparatus fibers that extend past the cytostome into the cytoplasm.

Discussions

INTERPRETATION (RESOLVED): Keep the deep fiber distinct from the whole oral apparatus and the cytostome. GO:0032123 denotes a narrow cytoskeletal fiber of the oral apparatus. GO:0031912 denotes the whole feeding apparatus, and GO:0031910 denotes the cytostome that the deep fiber extends past.
CURATION_TODO (OPEN): Resolve the exact molecular constituents of the deep fiber before adding components. GO:0032123 identifies the deep fiber as a cytoskeletal oral-apparatus fiber, but this GO-backed pass did not verify exact source-neutral InterPro, Pfam, NCBIfam or UniProtKB component groundings.

Evidence

GO:0032123 Gene Ontology cellular-component term for the ciliate oral-apparatus deep fiber.
GO:0005856 — cytoskeleton Gene Ontology relates GO:0032123 deep fiber to GO:0005856 cytoskeleton by part_of (BFO:0000050), not by is-a.
GO:0031912 OLS reports GO:0032123 deep fiber as part of the oral apparatus.
DOI:10.1016/S0091-679X(08)61528-9 Frankel 2000, Cell biology of Tetrahymena thermophila, Methods in Cell Biology.

Curation history

2026-09-30T20:50:25Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-30T20:51:55Z codex · EXPANDED_RECORD — Added GO synonymy, cytoskeleton parentage, oral-apparatus parthood, a Tetrahymena canonical example, GO-backed topology evidence, a nonmechanistic deep-fiber topology graph, and boundary and component grounding discussions.
2026-10-12T00:29:11Z codex · ADDRESS_SAVED_REVIEW — Addressed #2272: represented cytoskeleton as a containing whole via part_of, corrected relationship evidence, and preserved exact structure identity and all existing biological claims.

Source: data/structures/cytoskeleton/deep_fiber.yaml