identifier: METPO:1000306
label: temperature range
definition: A temperature phenotype with numerical limits that bounds the minimum
  and maximum ambient temperatures supporting growth of an organism.
definition_source: DOI:10.1016/s0300-9629(97)00003-0
trait_category: ENVIRONMENT
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- METPO:1000533
- METPO:1000535
evidence:
- reference: DOI:10.1016/s0300-9629(97)00003-0
  snippet: adapted to environments of high temperature
  notes: Thermophile-adaptation review supports the bounded ambient-temperature span
    over which membrane, enzyme, and bioenergetic adaptations sustain growth as the
    basis of the temperature-range phenotype.
- reference: DOI:10.1038/sj.embor.7400662
  snippet: decreased membrane fluidity
  notes: Psychrophile review supports cold-end membrane stress as a lower-bound growth
    constraint that low-temperature tolerance must overcome.
causal_graphs:
- graph_id: temperature_range_bounded_adaptation
  title: Temperature-range bounded thermal adaptation
  description: DOI-backed graph linking cold- and heat-tolerance to the bounded span
    of growth-supporting ambient temperatures.
  nodes:
  - node_id: temperature_range_trait
    label: temperature range
    node_type: TRAIT
    grounding: METPO:1000306
    description: Span of ambient temperatures supporting growth.
  - node_id: ambient_temperature
    label: ambient temperature
    node_type: ENVIRONMENTAL_FACTOR
    description: Ambient growth temperature imposed on the cell.
  - node_id: cold_tolerance
    label: cold tolerance
    node_type: BIOLOGICAL_PROCESS
    description: Capacity to maintain membrane fluidity and enzyme function at low
      ambient temperature.
  - node_id: heat_tolerance
    label: heat tolerance
    node_type: BIOLOGICAL_PROCESS
    description: Capacity to maintain protein folding and membrane integrity at high
      ambient temperature.
  - node_id: bounded_growth_window
    label: bounded temperature growth window
    node_type: BIOLOGICAL_PROCESS
    description: Span of ambient temperatures between the minimum and maximum that
      support growth.
  - node_id: membrane_lipid_unsaturation
    label: membrane lipid unsaturation
    node_type: BIOLOGICAL_PROCESS
    description: Increase in unsaturated fatty acids in membrane lipids in response
      to low temperature (homeoviscous adaptation).
  - node_id: lipid_desaturase_activity
    label: lipid desaturase activity
    node_type: MOLECULAR_FUNCTION
    description: Enzymatic introduction of double bonds into membrane fatty acids.
  - node_id: membrane_fluidity
    label: membrane fluidity
    node_type: QUALITY
    description: Physical fluidity of the cytoplasmic membrane that must be maintained
      for function at low temperature.
    grounding: METPO:1007505
  - node_id: chaperone_systems
    label: molecular chaperone systems
    node_type: BIOLOGICAL_PROCESS
    description: Heat-shock chaperone systems (e.g. DnaK/GroEL) that maintain protein
      folding at high temperature.
  - node_id: compatible_solutes
    label: compatible solutes
    node_type: CHEMICAL
    description: Cryoprotective osmolytes (e.g. glycine betaine, trehalose, glycerol)
      accumulated to protect against low-temperature stress.
    grounding: CHEBI:25728
  - node_id: two_component_cold_sensing
    label: two-component cold sensing
    node_type: BIOLOGICAL_PROCESS
    description: Two-component signal transduction triggered by changes in the liquid-crystalline
      membrane state at low temperature.
  edges:
  - subject: ambient_temperature
    predicate: defines
    object: bounded_growth_window
    description: Ambient temperature defines the axis over which the growth window
      is bounded.
    evidence:
    - reference: DOI:10.1016/s0300-9629(97)00003-0
      snippet: adapted to environments of high temperature
      notes: Supports ambient temperature as the axis bounding the growth window.
    predicate_id: METPO:2007500
  - subject: cold_tolerance
    predicate: defines
    object: bounded_growth_window
    description: Cold tolerance sets the lower bound of the temperature growth window.
    evidence:
    - reference: DOI:10.1038/sj.embor.7400662
      snippet: decreased membrane fluidity
      notes: Supports cold-end membrane and enzyme adaptation as the lower-bound mechanism.
    predicate_id: METPO:2007500
  - subject: heat_tolerance
    predicate: defines
    object: bounded_growth_window
    description: Heat tolerance sets the upper bound of the temperature growth window.
    evidence:
    - reference: DOI:10.1128/MMBR.65.1.1-43.2001
      snippet: resistant to irreversible inactivation at high temperatures
      notes: Supports protein-thermostability physiology as the upper-bound mechanism.
    predicate_id: METPO:2007500
  - subject: bounded_growth_window
    predicate: manifests as
    object: temperature_range_trait
    description: The bounded temperature growth window manifests the temperature-range
      phenotype.
    evidence:
    - reference: DOI:10.1016/s0300-9629(97)00003-0
      snippet: adapted to environments of high temperature
      notes: Supports the trait endpoint.
    predicate_id: METPO:2007400
  - subject: ambient_temperature
    predicate: increases
    object: membrane_lipid_unsaturation
    description: Decreased ambient temperature increases membrane lipid unsaturation
      via homeoviscous adaptation.
    evidence:
    - reference: DOI:10.1007/s12275-023-00031-x
      notes: E. coli increases unsaturated cis-vaccenic acid and decreases palmitic
        acid with cold; broad bacterial mechanism affecting the lower growth bound.
    predicate_id: RO:0002213
  - subject: lipid_desaturase_activity
    predicate: increases
    object: membrane_fluidity
    description: Lipid desaturase activity increases membrane fluidity at low temperature.
    evidence:
    - reference: DOI:10.37256/amtt.5220244537
      notes: Upregulation of genes for fatty acid synthesis/desaturation maintains
        membrane fluidity at low temperature.
    predicate_id: RO:0002213
  - subject: membrane_lipid_unsaturation
    predicate: increases
    object: membrane_fluidity
    description: Increased membrane lipid unsaturation maintains membrane fluidity
      at low temperature.
    evidence:
    - reference: DOI:10.37256/amtt.5220244537
      notes: Fatty acid desaturation maintains membrane fluidity, a broadly supported
        homeoviscous adaptation underpinning cold tolerance.
    predicate_id: RO:0002213
  - subject: membrane_fluidity
    predicate: enables
    object: cold_tolerance
    description: Maintenance of membrane fluidity enables cold tolerance at the lower
      temperature bound.
    evidence:
    - reference: DOI:10.37256/amtt.5220244537
      notes: Maintaining membrane fluidity at low temperature is a core mechanism
        supporting growth at the cold end of the range.
    predicate_id: RO:0002327
  - subject: ambient_temperature
    predicate: induces
    object: chaperone_systems
    description: Elevated ambient temperature induces molecular chaperone systems
      that support heat tolerance.
    evidence:
    - reference: DOI:10.1007/s12275-023-00031-x
      notes: Molecular chaperones DnaK/Hsp70 and GroEL are implicated in survival
        at high temperatures; broad across bacteria.
  - subject: chaperone_systems
    predicate: enables
    object: heat_tolerance
    description: Molecular chaperone systems enable heat tolerance at the upper temperature
      bound.
    evidence:
    - reference: DOI:10.1007/s12275-023-00031-x
      notes: Chaperone-mediated protein folding supports the upper-bound (Tmax) heat-tolerance
        mechanism.
    predicate_id: RO:0002327
  - subject: compatible_solutes
    predicate: protects against
    object: cold_tolerance
    description: Compatible solutes protect against low-temperature and freezing stress,
      supporting cold tolerance.
    evidence:
    - reference: DOI:10.37256/amtt.5220244537
      notes: Glycine, betaine, glycerol, and trehalose act as cryoprotectants and
        osmolytes; broad low-end mechanism.
  - subject: membrane_fluidity
    predicate: activates
    object: two_component_cold_sensing
    description: Changes in the liquid-crystalline membrane state activate two-component
      cold sensing.
    evidence:
    - reference: DOI:10.1007/s42770-023-01057-4
      notes: Cold sensing via changes in the liquid-crystalline membrane state that
        activate two-component signal transduction; generic edge linking membrane
        state to regulatory response.
    predicate_id: RO:0002213
curation_history:
- timestamp: '2026-05-05T01:35:46.814231+00:00'
  curator: seed_from_metpo
  action: SEEDED_FROM_METPO
  changes: imported from data/raw/metpo.owl (CLASS)
  llm_assisted: false
- timestamp: '2026-05-13T11:00:00-07:00'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added DOI-backed causal graph linking cold- and heat-tolerance to the bounded
    temperature-range phenotype.
  llm_assisted: true
- timestamp: '2026-05-23T21:30:06Z'
  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: '2026-05-24T07:37:39Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2007500×1).
  llm_assisted: true
- timestamp: '2026-05-26T05:00:47Z'
  curator: claude
  action: RENAME_PREDICATE_LABELS
  changes: 'Renamed 2 causal-edge predicate label(s) to align with existing groundings:
    sets → defines ×2.'
  llm_assisted: true
- timestamp: '2026-05-26T05:00:50Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2007500×2).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 8 evidence-backed generic edges (6 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:11Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 6 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (RO:0002213×4, RO:0002327×2).
  llm_assisted: true
- timestamp: '2026-06-24T17:21:18Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (METPO:1007505×1, CHEBI:25728×1).
  llm_assisted: true