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Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis

Compound specific isotopic analysis (CSIA) of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and spec...

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Autores principales: Bradley, Christina J., Madigan, Daniel J., Block, Barbara A., Popp, Brian N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3899081/
https://www.ncbi.nlm.nih.gov/pubmed/24465724
http://dx.doi.org/10.1371/journal.pone.0085818
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author Bradley, Christina J.
Madigan, Daniel J.
Block, Barbara A.
Popp, Brian N.
author_facet Bradley, Christina J.
Madigan, Daniel J.
Block, Barbara A.
Popp, Brian N.
author_sort Bradley, Christina J.
collection PubMed
description Compound specific isotopic analysis (CSIA) of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and specific trophic discrimination factors (TDFs) are largely unknown, limiting the application of CSIA to trophic studies. We determined nitrogen turnover rates of individual amino acids from a long-term (up to 1054 days) laboratory experiment using captive Pacific bluefin tuna, Thunnus orientalis (PBFT), a large endothermic pelagic fish fed a controlled diet. Small PBFT (white muscle δ(15)N∼11.5‰) were collected in San Diego, CA and transported to the Tuna Research and Conservation Center (TRCC) where they were fed a controlled diet with high δ(15)N values relative to PBFT white muscle (diet δ(15)N∼13.9‰). Half-lives of trophic and source amino acids ranged from 28.6 to 305.4 days and 67.5 to 136.2 days, respectively. The TDF for the weighted mean values of amino acids was 3.0 ‰, ranging from 2.2 to 15.8 ‰ for individual combinations of 6 trophic and 5 source amino acids. Changes in the δ(15)N values of amino acids across trophic levels are the underlying drivers of the trophic (15)N enrichment. Nearly all amino acid δ(15)N values in this experiment changed exponentially and could be described by a single compartment model. Significant differences in the rate of (15)N incorporation were found for source and trophic amino acids both within and between these groups. Varying half-lives of individual amino acids can be applied to migratory organisms as isotopic clocks, determining the length of time an individual has spent in a new environment. These results greatly enhance the ability to interpret compound specific isotope analyses in trophic studies.
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spelling pubmed-38990812014-01-24 Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis Bradley, Christina J. Madigan, Daniel J. Block, Barbara A. Popp, Brian N. PLoS One Research Article Compound specific isotopic analysis (CSIA) of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and specific trophic discrimination factors (TDFs) are largely unknown, limiting the application of CSIA to trophic studies. We determined nitrogen turnover rates of individual amino acids from a long-term (up to 1054 days) laboratory experiment using captive Pacific bluefin tuna, Thunnus orientalis (PBFT), a large endothermic pelagic fish fed a controlled diet. Small PBFT (white muscle δ(15)N∼11.5‰) were collected in San Diego, CA and transported to the Tuna Research and Conservation Center (TRCC) where they were fed a controlled diet with high δ(15)N values relative to PBFT white muscle (diet δ(15)N∼13.9‰). Half-lives of trophic and source amino acids ranged from 28.6 to 305.4 days and 67.5 to 136.2 days, respectively. The TDF for the weighted mean values of amino acids was 3.0 ‰, ranging from 2.2 to 15.8 ‰ for individual combinations of 6 trophic and 5 source amino acids. Changes in the δ(15)N values of amino acids across trophic levels are the underlying drivers of the trophic (15)N enrichment. Nearly all amino acid δ(15)N values in this experiment changed exponentially and could be described by a single compartment model. Significant differences in the rate of (15)N incorporation were found for source and trophic amino acids both within and between these groups. Varying half-lives of individual amino acids can be applied to migratory organisms as isotopic clocks, determining the length of time an individual has spent in a new environment. These results greatly enhance the ability to interpret compound specific isotope analyses in trophic studies. Public Library of Science 2014-01-22 /pmc/articles/PMC3899081/ /pubmed/24465724 http://dx.doi.org/10.1371/journal.pone.0085818 Text en © 2014 Bradley et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Bradley, Christina J.
Madigan, Daniel J.
Block, Barbara A.
Popp, Brian N.
Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title_full Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title_fullStr Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title_full_unstemmed Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title_short Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis
title_sort amino acid isotope incorporation and enrichment factors in pacific bluefin tuna, thunnus orientalis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3899081/
https://www.ncbi.nlm.nih.gov/pubmed/24465724
http://dx.doi.org/10.1371/journal.pone.0085818
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