thermotaxis

traitmech:000580 · CLASS · PROPOSED

A motile phenotype in which an organism biases its active movement in response to a temperature gradient.

Trait evidence (2)

DOI:10.7554/eLife.26607
detect and follow environmental temperature gradients

Paulick et al., Introduction; version 2, Version of Record dated 2017-08-31, https://cdn.elifesciences.org/articles/26607/elife-26607-v2.pdf. Figures 1-3 and their figure supplements distinguish behavioral gradients from FRET reporters and chemical adaptation. Temperature preference for movement is not a growth-temperature class.
DOI:10.1073/pnas.0709903105
responds to changes in temperature by modifying its motor behavior

Paster and Ryu, Abstract and Results: thermal pulses changed tethered-cell motor bias. Their inversion temperatures are assay-specific, not universal trait thresholds. This assay measures motor output rather than spatial accumulation.

Tar-mediated control of thermal migration

A receptor-modification-dependent thermal response changes swimming bias and realizes thermotaxis.

MECHANISTIC · The E. coli Tar-mediated arm, not a universal microbial mechanism or a complete Tar/Tsr accumulation model. Engineered receptor experiments establish the Tar transitions. Interplay with Tsr and chemical adaptation changes the intact-cell response.

Edge evidence

temperature change during movement modulates Tar aspartate chemoreceptor RO:0002211
Temperature changes elicit a Tar response when its modification state permits thermosensing.
- DOI:10.1074/jbc.271.30.17932 Tar comes to function as a thermoreceptor Abstract: deamidation enables the thermal response; the primary translational product is not a thermoreceptor.
Tar covalent modification state modulates Tar aspartate chemoreceptor RO:0002211
Covalent modification changes the receptor's warm, cold or null response state.
- DOI:10.1128/jb.179.21.6573-6580.1997 thermosensing function that is modulated by covalent modification of its four methylation sites Abstract: the mutational study distinguishes deamidation from methylation and tests receptor thermosensing, not a universal preferred temperature.
Tar aspartate chemoreceptor regulates thermal control of run-and-tumble bias RO:0002211
Tar-mediated signaling changes swimming bias, with the response sign depending on receptor modification.
- DOI:10.1074/jbc.271.30.17932 eliciting a smooth-swimming signal upon increase of temperature Abstract: this warm response applies to deamidated, unmethylated Tar; the heavily methylated form instead signals smooth swimming on cooling. Intermediate phosphorelay steps are compressed, not bypassed.
thermal control of run-and-tumble bias contributes to thermotaxis RO:0002326
Temperature-dependent run-and-tumble statistics bias migration along a thermal gradient.
- DOI:10.1073/pnas.0709903105 This stochastic strategy biases the cell's random walk Introduction: temporal temperature sensing biases runs and tumbles, giving net movement along spatial gradients. The separate motor assay is not itself a migration measurement.
thermotaxis confers thermotaxis METPO:2007700
Temperature-guided migration realizes the organismal thermotaxis phenotype.
- DOI:10.7554/eLife.26607 cells accumulated towards the warmer side of the gradient Results, Figure 1C: buffer-adapted swimming cells; chemical adaptation can alter the direction (Figure 2).

Protein and taxon examples

Graph node Protein Taxon UniProt status Role and evidence

Tar aspartate chemoreceptor

Graph node	Protein	Taxon	UniProt status	Role and evidence
Tar aspartate chemoreceptor	`UniProtKB:P07017` Methyl-accepting chemotaxis protein II (tar)	Escherichia coli K-12 `NCBITaxon:83333`	`REVIEWED` retrieved 2026-10-03 · entry v208 · sequence v2	Tar component of the K-12 thermal response; not the entire receptor array. `DOI:10.7554/eLife.26607` both Tar- and Tsr-only cells exhibited thermophilic responses Results, Figure 3A and Methods identify K-12 Tar-only receptor experiments; UniProt verifies protein identity.

UniProtKB:P07017
Methyl-accepting chemotaxis protein II (tar)

Escherichia coli K-12
NCBITaxon:83333

REVIEWED
retrieved 2026-10-03 · entry v208 · sequence v2

Tar component of the K-12 thermal response; not the entire receptor array.

DOI:10.7554/eLife.26607 both Tar- and Tsr-only cells exhibited thermophilic responses Results, Figure 3A and Methods identify K-12 Tar-only receptor experiments; UniProt verifies protein identity.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.7554/eLife.26607

Parent traits (1)

motile METPO:1000702

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.

Escherichia coli K-12 NCBITaxon:83333 DOI:10.7554/eLife.26607 AW405, a K-12 derivative carrying a GFP marker, showed thermal migration in microfluidic gradients (Figures 1C and 2D-E; Methods: Strains and plasmids). It is not the engineered VS223 FRET reporter or the MG1655 growth assay.

Discussions and Knowledge Gaps (1)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Resolve assay-dependent response inversion without imposing a universal temperature threshold.

KNOWLEDGE GAP OPEN thermotaxis-context-and-mapping-boundaries · raised by codex · 2026-10-03

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.

DOI:10.1073/pnas.0709903105 reports thermal-response inversion under its tethered-cell conditions. DOI:10.7554/eLife.26607 instead finds continued warm-seeking in buffer under flow; its Discussion suggests residual chemical stimulation as one explanation of earlier results, not a proven correction. Retain medium, adaptation, strain and assay context. Growth optima, passive thermophoresis and temperature-dependent speed alone do not establish thermotaxis. GO:0043052 is a biological process (QuickGO checked 2026-10-03), so it grounds the process node rather than an equivalent xref on the disposition. The Tar arm does not describe every thermotactic microbe.

Curation history

2026-10-03T22:20:00Z · MINTED_TRAITMECH_ID · codex
Added thermotaxis with four primary DOI sources, exact snippets, a K-12 behavioral example and a Tar-mediated causal graph. Verified P07017, NCBITaxon:83333 and GO:0043052 at authorities. Ignored-and-hidden searches found no exact record or METPO term; reserved METPO:1053400 in proposal v457. Kept assay-dependent inversion separate from growth-temperature preference.