identifier: METPO:1000679 label: pleomorphic shaped definition: A cell shape characterized by variable and irregular morphology, where individual cells within a population exhibit multiple distinct shapes. definition_source: DOI:10.1146/annurev-cellbio-101011-155745 trait_category: MORPHOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000666 synonyms: - synonym_text: S_star_dumbbell_pleomorphic synonym_type: RELATED_SYNONYM source: metpo.owl - synonym_text: pleomorphic synonym_type: RELATED_SYNONYM source: metpo.owl - synonym_text: pleomorphic-shaped synonym_type: RELATED_SYNONYM source: metpo.owl created_by: Jed Dongjin Kim-Ozaeta evidence: - reference: DOI:10.1146/annurev-cellbio-101011-155745 snippet: cell shape is genetically determined notes: Cell-shape review establishes pleomorphism as a phenotype of relaxed or absent cytoskeletal/wall shape control. - reference: DOI:10.1126/science.1170701 snippet: cell-wall-deficient L-forms notes: L-form review supports pleomorphism in wall-deficient or wall-less cells. canonical_examples: - taxon_id: NCBITaxon:2093 taxon_label: Mycoplasma note: "Cell-wall-less, pleomorphic bacteria; the textbook genus for variable cell shape." reference: PMID:9841667 causal_graphs: - graph_id: pleomorphic_shaped_relaxed_shape_control title: Pleomorphic-shape relaxed shape control description: DOI-backed graph linking loss or weakening of cytoskeletal and cell-wall shape control to multi-morphology populations. nodes: - node_id: pleomorphic_shaped_trait label: pleomorphic shaped node_type: TRAIT grounding: METPO:1000679 description: Population exhibiting multiple cell shapes. - node_id: weak_cytoskeleton label: weak/absent shape-determining cytoskeleton node_type: GENE_OR_PROTEIN description: Reduced MreB or analogous shape-determining cytoskeletal activity. - node_id: weak_cell_wall label: weak or absent peptidoglycan wall node_type: CELLULAR_LOCALIZATION description: Cell wall reduced (L-form/Mycoplasma) or compromised. grounding: GO:0009274 - node_id: variable_geometry label: variable cell geometry node_type: BIOLOGICAL_PROCESS description: Population-level variability in cell shape. - node_id: pg_synthesis_inhibition label: inhibition of peptidoglycan precursor synthesis node_type: BIOLOGICAL_PROCESS description: Repression or inhibition of cell-wall precursor synthesis. - node_id: lform_wall_deficient_state label: L-form / wall-deficient state node_type: STATE description: Wall-deficient cellular state with pleomorphic morphology. - node_id: excess_membrane_synthesis label: excess membrane synthesis node_type: BIOLOGICAL_PROCESS description: Increased membrane synthesis raising surface area-to-volume ratio. - node_id: blebbing_scission_proliferation label: blebbing-tubulation-scission proliferation node_type: BIOLOGICAL_PROCESS description: FtsZ-independent proliferation of wall-deficient cells via membrane blebbing and scission. - node_id: oxidative_stress_ros label: oxidative stress / ROS from respiratory chain node_type: BIOLOGICAL_PROCESS description: Reactive oxygen species generated by respiratory chain causing oxidative stress. - node_id: loss_of_cell_wall label: loss of cell wall node_type: BIOLOGICAL_PROCESS description: Loss of the peptidoglycan cell wall in walled bacteria. edges: - subject: weak_cytoskeleton predicate: relaxes object: variable_geometry description: Weak shape-determining cytoskeleton permits multiple geometries. evidence: - reference: DOI:10.1146/annurev-cellbio-101011-155745 snippet: cell shape is genetically determined notes: Supports cytoskeletal loss as a driver of multi-shape populations. - subject: weak_cell_wall predicate: enables object: variable_geometry description: Reduced or absent cell wall enables membrane-driven shape variability. evidence: - reference: DOI:10.1126/science.1170701 snippet: cell-wall-deficient L-forms notes: Supports wall deficiency as a basis for L-form pleomorphism. predicate_id: RO:0002327 - subject: variable_geometry predicate: manifests as object: pleomorphic_shaped_trait description: Variable geometry across cells manifests pleomorphism. evidence: - reference: DOI:10.1146/annurev-cellbio-101011-155745 snippet: cell shape is genetically determined notes: Supports the trait endpoint. predicate_id: METPO:2007400 - subject: pg_synthesis_inhibition predicate: causes transition to object: lform_wall_deficient_state description: Inhibition of cell-wall precursor synthesis stimulates the L-form transition. evidence: - reference: DOI:10.1098/rstb.2015.0494 notes: Repression or inhibition of cell wall precursor synthesis can stimulate the L-form transition in a wide range of bacteria. - subject: lform_wall_deficient_state predicate: manifests as object: pleomorphic_shaped_trait description: The wall-deficient L-form state presents as pleomorphic morphology. evidence: - reference: DOI:10.1098/rstb.2015.0494 notes: Wall-deficient L-form state is characterized by pleomorphic morphology across diverse bacteria. predicate_id: METPO:2007400 - subject: excess_membrane_synthesis predicate: drives proliferation of object: lform_wall_deficient_state description: Increased membrane synthesis drives proliferation of wall-free pleomorphic L-forms. evidence: - reference: DOI:10.1098/rstb.2015.0494 notes: Increasing membrane synthesis promotes the unusual form of proliferation used by L-forms, involving disorganized membrane blebbing/vesiculation. - subject: excess_membrane_synthesis predicate: enables object: blebbing_scission_proliferation description: Increased membrane synthesis / elevated surface area-to-volume ratio enables blebbing-scission proliferation. evidence: - reference: DOI:10.1042/bst20160435 notes: Proliferation appears to require only an increased rate of membrane synthesis, producing an increased surface area-to-volume ratio. predicate_id: RO:0002327 - subject: oxidative_stress_ros predicate: limits or kills object: lform_wall_deficient_state description: ROS-driven oxidative stress constrains survival of wall-deficient cells. evidence: - reference: DOI:10.1016/j.tim.2019.07.008 notes: Reactive oxygen species are formed, causing oxidative stress and ultimately killing the wall-deficient cells. - subject: loss_of_cell_wall predicate: causes object: pleomorphic_shaped_trait description: Loss of the cell wall causes spherical or pleomorphic morphology in rod-shaped bacteria. evidence: - reference: DOI:10.3390/bioengineering11010081 notes: Rod-shaped bacteria (e.g., E. coli, B. subtilis) exhibit spherical or pleomorphic shapes due to the lack of cell walls. predicate_id: biolink:causes curation_history: - timestamp: '2026-05-05T01:35:46.892214+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-11T22:45:00-07:00' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added DOI-backed causal graph linking weak shape-determining cytoskeleton and reduced cell wall to pleomorphic populations. llm_assisted: true - timestamp: '2026-05-20T03:35:31Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002327×1). llm_assisted: true - timestamp: '2026-05-23T21:30:07Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2007400×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 6 evidence-backed generic edges (6 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:13Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2007400×1, RO:0002327×1, biolink:causes×1). llm_assisted: true