Phenotype association

Feature-level pathway inference before metabolite identification

Infer pathway and metabolic-network hypotheses from significant untargeted MS features before assigning every metabolite identity.

PLOS Computational Biology · 2013 · 10.1371/journal.pcbi.1003123

LC-MSUntargeted metabolomicsPhenotype association

What does this strategy enable?

The mummichog method connects ambiguous mass-to-metabolite matches to metabolic-network structure. Enrichment is evaluated against the measured feature background, allowing collective evidence to prioritize biological hypotheses for experimental follow-up.

Transferable workflow

Workflow

  1. 1

    Define significant and background features

    Prepare significant feature masses and the full measured feature list from the comparison.

  2. 2

    Map candidate metabolites to a network

    Use mass accuracy, ionization assumptions and a suitable metabolic model to retain plausible matches.

  3. 3

    Evaluate network and pathway enrichment

    Compare observed enrichment with permutations from the feature background.

  4. 4

    Validate prioritized hypotheses

    Follow up selected metabolites and pathways with independent measurements.

Connected resources

Tools used in this strategy

Strategy profile

Related objectives

Metabolite annotation

Components

Statistical analysis, Annotation or identification, Biological validation

Scope and considerations

Designed for

  • Functional interpretation when many significant features remain unidentified.

Important requirements

  • Feature statistics, measured background and a relevant metabolic model.

Considerations

  • Enrichment is a hypothesis, not confirmation of individual identities or a measurement of flux.
  • Background selection and ambiguous ion assignments influence results.

Reusable resources

✓ Published method available

Publication

Li S, Park Y, Duraisingham S, et al. Predicting Network Activity from High Throughput Metabolomics. PLOS Computational Biology 9, e1003123 (2013).

doi:10.1371/journal.pcbi.1003123