ReviewOecologia2017
'Trophic' and 'source' amino acids in trophic estimation: a likely metabolic explanation.
Review in Oecologia, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 56 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
56 citing papers in PubMed.
- Amino Acid Nitrogen Isotope Ratios Respond to Fish and Meat Intake in a 12-Week Inpatient Feeding Study of Men.The Journal of nutrition · 2022Trial
- Marine heatwaves suppress nutrient utilization and reproductive flexibility in humpback whales.iScience · 2026Article
- Advancing Amino Acid Isotope-Inferred Trophic Ecology in an Apex Predator: Insights From a Data-Rich Killer Whale Population.Ecology and evolution · 2026Article
- Nutritional adaptations to early maize cultivation: Earliest isotopic evidence of maize-based animal provisioning in the Neotropics.Science advances · 2026Article
- Mixotrophy emerges as an optimal strategy in mature waters of the Amazon River plume.Communications biology · 2026Article
- Article
- Repeated migration informs amino acid nitrogen isotope incorporation in the African elephant Loxodonta africana.Oecologia · 2026Article
- Microbially derived essential amino acids compensate for dietary deficiencies in an ecologically relevant mammalian host.The ISME journal · 2026Article
- Reliance on blue, green, and brown energy channels drives a shift in the trophic position of riparian spiders.Ecology · 2026Article
- Investigating human paleodiet at Mesolithic Yuzhniy Oleniy Ostrov, Karelia using a multi-proxy stable isotope approach.PloS one · 2026Article
- Stable Carbon Isotope Analysis of Perfluorooctanoic Acid (PFOA) by Microflow-High Pressure Liquid Chromatography-Orbitrap Mass Spectrometry.Rapid communications in mass spectrometry : RCM · 2025Article
- Article
- Exploring Early Childhood Diet, Stress, Trophic Position and Dietary Protein Quality Using Amino Acid Nitrogen Isotope Compositions of Fingernail Keratin.American journal of biological anthropology · 2025Article
- Trophic dynamics and metabolic pathways in host parasite interactions revealed by nitrogen isotope analysis of amino acids in multiple tissues.Scientific reports · 2025Article
- Compound-Specific and Intramolecular δAnalytical chemistry · 2025Article
- Investigating long-term trophic stability in North Atlantic cod (Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2025Article
- High-resolution isotope dietary analysis of Mesolithic and Neolithic humans from Franchthi Cave, Greece.PloS one · 2025Article
- Comparison of δScientific reports · 2024Article
- Multi-Omics Study on Molecular Mechanisms of Single-Atom Fe-Doped Two-Dimensional Conjugated Phthalocyanine Framework for Photocatalytic Antibacterial Performance.Molecules (Basel, Switzerland) · 2024Article
- The Effects of Composite Alkali-Stored SpentAnimals : an open access journal from MDPI · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
1 author.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Amino acid nitrogen isotopic analysis is a relatively new method for estimating trophic position. It uses the isotopic difference between an individual's 'trophic' and 'source' amino acids to determine its trophic position. So far, there is no accepted explanation for the mechanism by which the isotopic signals in 'trophic' and 'source' amino acids arise. Yet without a metabolic understanding, the utility of nitrogen isotopic analyses as a method for probing trophic relations, at either bulk tissue or amino acid level, is limited. I draw on isotopic tracer studies of protein metabolism, together with a consideration of amino acid metabolic pathways, to suggest that the 'trophic'/'source' groupings have a fundamental metabolic origin, to do with the cycling of amino-nitrogen between amino acids. 'Trophic' amino acids are those whose amino-nitrogens are interchangeable, part of a metabolic amino-nitrogen pool, and 'source' amino acids are those whose amino-nitrogens are not interchangeable with the metabolic pool. Nitrogen isotopic values of 'trophic' amino acids will reflect an averaged isotopic signal of all such dietary amino acids, offset by the integrated effect of isotopic fractionation from nitrogen cycling, and modulated by metabolic and physiological effects. Isotopic values of 'source' amino acids will be more closely linked to those of equivalent dietary amino acids, but also modulated by metabolism and physiology. The complexity of nitrogen cycling suggests that a single identifiable value for 'trophic discrimination factors' is unlikely to exist. Greater consideration of physiology and metabolism should help in better understanding observed patterns in nitrogen isotopic values.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.