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Poupin N, Bos C, Mariotti F, Huneau JF, Tomé D, Fouillet H. The nature of the dietary protein impacts the tissue-to-diet 15N discrimination factors in laboratory rats. PLoS One 2011; 6:e28046. [PMID: 22132207 PMCID: PMC3222673 DOI: 10.1371/journal.pone.0028046] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 10/31/2011] [Indexed: 11/18/2022] Open
Abstract
Due to the existence of isotope effects on some metabolic pathways of amino acid and protein metabolism, animal tissues are 15N-enriched relative to their dietary nitrogen sources and this 15N enrichment varies among different tissues and metabolic pools. The magnitude of the tissue-to-diet discrimination (Δ15N) has also been shown to depend on dietary factors. Since dietary protein sources affect amino acid and protein metabolism, we hypothesized that they would impact this discrimination factor, with selective effects at the tissue level. To test this hypothesis, we investigated in rats the influence of a milk or soy protein-based diet on Δ15N in various nitrogen fractions (urea, protein and non-protein fractions) of blood and tissues, focusing on visceral tissues. Regardless of the diet, the different protein fractions of blood and tissues were generally 15N-enriched relative to their non-protein fraction and to the diet (Δ15N>0), with large variations in the Δ15N between tissue proteins. Δ15N values were markedly lower in tissue proteins of rats fed milk proteins compared to those fed soy proteins, in all sampled tissues except in the intestine, and the amplitude of Δ15N differences between diets differed between tissues. Both between-tissue and between-diet Δ15N differences are probably related to modulations of the relative orientation of dietary and endogenous amino acids in the different metabolic pathways. More specifically, the smaller Δ15N values observed in tissue proteins with milk than soy dietary protein may be due to a slightly more direct channeling of dietary amino acids for tissue protein renewal and to a lower recycling of amino acids through fractionating pathways. In conclusion, the present data indicate that natural Δ15N of tissue are sensitive markers of the specific subtle regional modifications of the protein and amino acid metabolism induced by the protein dietary source.
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Affiliation(s)
- Nathalie Poupin
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Cécile Bos
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - François Mariotti
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Jean-François Huneau
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Daniel Tomé
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
| | - Hélène Fouillet
- INRA, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- AgroParisTech, CRNH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France
- * E-mail:
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Stable nitrogen and carbon isotope discrimination between juveniles and adults in an income-breeding small mammal (Peromyscus maniculatus). Mamm Biol 2011. [DOI: 10.1016/j.mambio.2011.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Shaner PJL, Macko SA. Trophic shifts of a generalist consumer in response to resource pulses. PLoS One 2011; 6:e17970. [PMID: 21437248 PMCID: PMC3060883 DOI: 10.1371/journal.pone.0017970] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 02/17/2011] [Indexed: 11/29/2022] Open
Abstract
Trophic shifts of generalist consumers can have broad food-web and biodiversity consequences through altered trophic flows and vertical diversity. Previous studies have used trophic shifts as indicators of food-web responses to perturbations, such as species invasion, and spatial or temporal subsidies. Resource pulses, as a form of temporal subsidies, have been found to be quite common among various ecosystems, affecting organisms at multiple trophic levels. Although diet switching of generalist consumers in response to resource pulses is well documented, few studies have examined if the switch involves trophic shifts, and if so, the directions and magnitudes of the shifts. In this study, we used stable carbon and nitrogen isotopes with a Bayesian multi-source mixing model to estimate proportional contributions of three trophic groups (i.e. producer, consumer, and fungus-detritivore) to the diets of the White-footed mouse (Peromyscus leucopus) receiving an artificial seed pulse or a naturally-occurring cicadas pulse. Our results demonstrated that resource pulses can drive trophic shifts in the mice. Specifically, the producer contribution to the mouse diets was increased by 32% with the seed pulse at both sites examined. The consumer contribution to the mouse diets was also increased by 29% with the cicadas pulse in one of the two grids examined. However, the pattern was reversed in the second grid, with a 13% decrease in the consumer contribution with the cicadas pulse. These findings suggest that generalist consumers may play different functional roles in food webs under perturbations of resource pulses. This study provides one of the few highly quantitative descriptions on dietary and trophic shifts of a key consumer in forest food webs, which may help future studies to form specific predictions on changes in trophic interactions following resource pulses.
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Affiliation(s)
- Pei-Jen L Shaner
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
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Yeung EH, Saudek CD, Jahren AH, Kao WHL, Islas M, Kraft R, Coresh J, Anderson CAM. Evaluation of a novel isotope biomarker for dietary consumption of sweets. Am J Epidemiol 2010; 172:1045-52. [PMID: 20817784 DOI: 10.1093/aje/kwq247] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Carbon isotopic signatures ("δ¹³C") might reflect consumption of corn- and cane-based sweeteners. The authors hypothesized that the δ¹³C value of human serum is higher for individuals with high versus low intakes of corn- and cane-based sweeteners (measured as sweetened beverage intake). They conducted a cross-sectional study within the Atherosclerosis Risk in Communities Magnetic Resonance Imaging study (Maryland, 2005-2006). Diet was assessed by food frequency questionnaire, and blinded serum samples were assayed by natural abundance stable isotope mass spectroscopy. Studied were 186 participants (53% male; mean age, 71 years; mean body mass index, 30 kg/m²). Serum δ¹³C values for individuals with high sweetened beverage intakes were significantly higher than for those with low intakes (-19.15‰ vs. -19.47‰, P < 0.001). Serum δ¹³C value increased 0.20‰ for every serving/day of sweetened beverages (P < 0.01). The association between sweetened beverages and serum δ¹³C value remained significant after adjustment for confounding by corn-based product intake (P < 0.001). Serum δ¹³C values were also associated with waist circumference, body mass index, and waist-to-hip ratio. This study provides the first known evidence that the δ¹³C value of human serum differs between persons consuming low and high amounts of sweets. Within the proper framework, serum δ¹³C value could be developed into an objective biomarker promoting more reliable assessment of dietary sweets intake.
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Affiliation(s)
- Edwina H Yeung
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
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55
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Warne RW, Gilman CA, Wolf BO. Tissue-carbon incorporation rates in lizards: implications for ecological studies using stable isotopes in terrestrial ectotherms. Physiol Biochem Zool 2010; 83:608-17. [PMID: 20441446 DOI: 10.1086/651585] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Carbon stable isotope (delta(13)C) analysis can be used to infer the origin and to estimate the flow of nutrient resources through animals and across ecological compartments. These applications require knowledge of the rates at which carbon is incorporated into animal tissues and diet-to-tissue discrimination factors (Delta(13)C). Studies of carbon dynamics in terrestrial vertebrates to date have focused almost solely on endothermic animals; ectotherms such as reptiles have received little attention. Here we determined carbon incorporation rates and Delta(13)C in tissues of prairie lizards (Sceloporus undulatus consobrinus) and collared lizards (Crotaphytus collaris). The smaller lizard, S. undulatus, had carbon retention times of 25 and 61 d in plasma and red blood cells (RBC), respectively, compared with 44 and 311 d for the larger C. collaris. Liver, muscle, and skin carbon retention times for S. undulatus were 21, 81, and 94 d. Growth contributed 9%-19% of the carbon incorporated into these tissues. This contribution is similar to endotherms measured at comparable developmental stages. Mean Delta(13)C for plasma (-0.2 per thousand +/- 0.4 per thousand Vienna Pee Dee Belemnite Standard) and RBCs (-1.3 per thousand +/- 0.8 per thousand) were similar to values reported for other vertebrates. Carbon incorporation rates for these ectotherms, however, are seven times slower than in similarly sized adult endotherms. Although a limited comparison with data for warm-water fishes suggests comparable incorporation rates between aquatic and terrestrial ectotherms, this study highlights the lack of experimental data for isotope dynamics in ectotherms across a range of temperatures, body sizes, and developmental stages.
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Affiliation(s)
- Robin W Warne
- Biology Department, University of New Mexico, Albuquerque, NM 87131-0001, USA.
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DeMots RL, Novak JM, Gaines KF, Gregor AJ, Romanek CS, Soluk DA. Tissue–diet discrimination factors and turnover of stable carbon and nitrogen isotopes in white-footed mice (Peromyscus leucopus). CAN J ZOOL 2010. [DOI: 10.1139/z10-063] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stable isotope analysis has become an increasingly valuable tool in investigating animal ecology. Here we document the turnover rates for carbon in the liver, muscle, and whole blood tissue, as well as the tissue–diet discrimination values for carbon and nitrogen isotopes in the liver, whole blood, muscle, and hair, of the white-footed mouse ( Peromyscus leucopus (Rafinesque, 1818)). A 168-day diet-switching experiment was conducted with a laboratory population of white-footed mice. The δ13C values for all tissues deviated less than 1‰ from those of the diet except for whole blood, which had a slightly higher tissue–diet discrimination factor of 1.8‰. All tissues were enriched in 15N by approximately 3‰ relative to the diet except for liver tissue, which was 4.5‰ higher than the dietary δ15N value. Turnover rates for tissues of white-footed mice were ranked liver > whole blood > muscle. The half-lives calculated for liver tissue differed significantly between the two diet switches performed in this experiment. We demonstrate that there is potential for variation in tissue–diet discrimination values and tissue turnover rates between even closely related species. These findings highlight the importance of determining species-specific estimates of these parameters prior to the use of stable isotope analysis in field investigations of animal ecology.
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Affiliation(s)
- Rachel L. DeMots
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
| | - James M. Novak
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
| | - Karen F. Gaines
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
| | - Aaron J. Gregor
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
| | - Christopher S. Romanek
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
| | - Daniel A. Soluk
- University of South Dakota, Department of Biology, 414 East Clark Street, Vermillion, SD 57069, USA
- Eastern Illinois University, Department of Biological Sciences, 600 Lincoln Avenue, Charleston, IL 61920-3099, USA
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
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Halley DJ, Minagawa M, Nieminen M, Gaare E. Diet: tissue stable isotope fractionation of carbon and nitrogen in blood plasma and whole blood of male reindeer Rangifer tarandus. Polar Biol 2010. [DOI: 10.1007/s00300-010-0817-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bauchinger U, McWilliams S. Carbon turnover in tissues of a passerine bird: allometry, isotopic clocks, and phenotypic flexibility in organ size. Physiol Biochem Zool 2010; 82:787-97. [PMID: 19785542 DOI: 10.1086/605548] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Stable isotopes are an important tool for physiological and behavioral ecologists, although their usefulness depends on a thorough understanding of the dynamics of isotope incorporation into tissue(s) over time. In contrast to hair, claws, and feathers, most animal tissues continuously incorporate carbon (and other elements), and so carbon isotope values may change over time, depending on resource use and tissue-specific metabolic rates. Here we report the carbon turnover rate for 12 tissues from a passerine bird, the zebra finch (Taeniopygia guttata). We measured average carbon retention time (tau) for 8 d for small intestine; 10-13 d for gizzard, kidney, liver, pancreas, and proventriculus; 17-21 d for heart, brain, blood, and flight muscle; and 26-28 d for leg muscle and skin. We used these data, along with the few other published estimates, to confirm that the fractional rate of isotopic turnover for red blood cells, whole blood, liver, and leg muscle scales with body mass to approximately the -1/4 power. Our data also support several key assumptions of the "isotopic-clock" model, which uses differences in isotope value between tissues, along with estimates of turnover rate of these tissues, to predict time elapsed since a diet shift. Finally, we show that between-tissues differences in turnover rate largely, but not entirely, explain the extent of phenotypic flexibility in organs of garden warblers during their long-distance flight across the Sahara Desert during spring. More studies that measure tissue-specific protein synthesis, metabolic rate, and elemental turnover in many tissues from a variety of animals are needed.
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Affiliation(s)
- Ulf Bauchinger
- Department Biologie II, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany.
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59
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Bauchinger U, Keil J, McKinney RA, Starck JM, McWilliams SR. Exposure to cold but not exercise increases carbon turnover rates in specific tissues of a passerine. J Exp Biol 2010; 213:526-34. [DOI: 10.1242/jeb.037408] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Carbon turnover differs between tissues within an animal, but the extent to which ecologically relevant increases in metabolism affect carbon turnover rates is largely unknown. We tested the energy expenditure and protein turnover hypotheses that predict increased carbon turnover, either in association with increased daily energy expenditure, or in concert with tissue-specific increased protein metabolism. We used stable-isotope-labeled diets to quantify the rate of carbon turnover in 12 different tissues for three groups of zebra finches (Taeniopygia guttata): cold-exposed birds kept at ambient temperatures below their thermoneutral zone, exercised birds that were flown for 2 h per day in a flight arena, and control birds that were kept at ambient temperatures within their thermoneutral zone and that were not exercised. We found that increases in metabolism associated with cold-exposure but not exercise produced measurable increases in carbon turnover rate of, on average, 2.4±0.3 days for pectoral muscle, gizzard, pancreas and heart, even though daily energy intake was similar for exercised and cold-exposed birds. This evidence does not support the energy expenditure hypothesis, and we invoke two physiological processes related to protein metabolism that can explain these treatment effects: organ mass increase and tissue-specific increase in activity. Such changes in carbon turnover rate associated with cold temperatures translate into substantial variation in the estimated time window for which resource use is estimated and this has important ecological relevance.
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Affiliation(s)
- U. Bauchinger
- Department Biology II, University of Munich (LMU), Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
- University of Rhode Island (URI), Kingston, RI 02881, USA
| | - J. Keil
- Department Biology II, University of Munich (LMU), Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
| | - R. A. McKinney
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Lab, Atlantic Ecology Division, Narragansett, RI 02882, USA
| | - J. M. Starck
- Department Biology II, University of Munich (LMU), Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
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Smith JJ, Millar JS, Longstaffe FJ, Boonstra R. The effect of metabolic rate on stable carbon and nitrogen isotope compositions in deer mice, Peromyscus maniculatus. CAN J ZOOL 2010. [DOI: 10.1139/z09-116] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The stable isotopic compositions of nitrogen and carbon in animal tissues reflect diet. However, factors other than diet can also affect these stable isotope ratios, leading to misinterpretations of diet composition. To test the hypothesis that variation in metabolic rate alters the isotopic compositions of tissues, deer mice ( Peromyscus maniculatus (Wagner, 1845)) were kept at three temperatures (thermoneutral (23 °C), cool (5 °C), and cold (–10 °C)) and fed ad libitum. The changes in carbon and nitrogen isotope compositions of liver associated with the thermoneutral versus cool and cold conditions were very small in comparison with those arising from differences in diet. We conclude that temperature-induced variations in metabolic rate are insufficient to produce differences in the stable carbon or nitrogen isotope compositions that could be mistaken for changes in diet.
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Affiliation(s)
- J. J. Smith
- Department of Biology, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Department of Earth Sciences, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
| | - J. S. Millar
- Department of Biology, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Department of Earth Sciences, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
| | - F. J. Longstaffe
- Department of Biology, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Department of Earth Sciences, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
| | - R. Boonstra
- Department of Biology, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Department of Earth Sciences, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
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del Rio CM, Wolf N, Carleton SA, Gannes LZ. Isotopic ecology ten years after a call for more laboratory experiments. Biol Rev Camb Philos Soc 2008; 84:91-111. [PMID: 19046398 DOI: 10.1111/j.1469-185x.2008.00064.x] [Citation(s) in RCA: 420] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
About 10 years ago, reviews of the use of stable isotopes in animal ecology predicted explosive growth in this field and called for laboratory experiments to provide a mechanistic foundation to this growth. They identified four major areas of inquiry: (1) the dynamics of isotopic incorporation, (2) mixing models, (3) the problem of routing, and (4) trophic discrimination factors. Because these areas remain central to isotopic ecology, we use them as organising foci to review the experimental results that isotopic ecologists have collected in the intervening 10 years since the call for laboratory experiments. We also review the models that have been built to explain and organise experimental results in these areas.
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Kraft RA, Jahren AH, Saudek CD. Clinical-scale investigation of stable isotopes in human blood: delta13C and delta15N from 406 patients at the Johns Hopkins Medical Institutions. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:3683-3692. [PMID: 18951415 DOI: 10.1002/rcm.3780] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Objective chemical biomarkers are needed in clinical studies of diet-related diseases to supplement subjective self-reporting methods. We report on several critical experiments for the development of clinically legitimate dietary stable isotope biomarkers within human blood. Our examination of human blood revealed the following: (1) Within blood clot and serum from anonymous individuals (201 males, 205 females) we observed: mean serum delta13C = -19.1 +/- 0.8 per thousand (standard deviation, SD); clot, -19.3 +/- 0.8 per thousand (SD); range = -15.8 per thousand to -23.4 per thousand. Highly statistically significant differences are observed between clot and serum, males and females for both clot and serum. For 15N (n = 206), mean serum = +8.8 +/- 0.5 per thousand (SD); clot +7.4 +/- 0.4 per thousand (SD); range = +6.3 per thousand to +10.5 per thousand. Blood serum is enriched in 15N relative to blood clot by +1.4 per thousand on average, which may reflect differing protein amino acid content. Serum nitrogen is statistically significantly different for males and females, however, clot shows no statistical difference. (2) Relative to clot, capillary blood is marginally different for 13C, but not 15N. Clot 13C is not significantly different from serum; however, it is depleted in 15N by 1.5 per thousand relative to serum. (3) We assessed the effect of blood additives (sodium fluoride and polymerized acrylamide resin) and laboratory process (autoclaving, freeze drying) commonly used to preserve or prepare venous blood. On average, no alteration in delta13C or delta15N is detected compared with unadulterated blood from the same individual. (4) Storage of blood with and without the additives described above for a period of up to 115 days exhibits statistically significant differences for 13C and 15N for sodium fluoride. However, storage for unadulterated blood and blood preserved with polymerized acrylamide resin does not change the delta13C or delta15N isotopic composition of the blood in a significant way. With these experiments, we gain a clinical context for future development of a stable isotope based dietary biomarker.
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Affiliation(s)
- Rebecca A Kraft
- Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, MD, USA.
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Guelinckx J, Maes J, Geysen B, Ollevier F. Estuarine recruitment of a marine goby reconstructed with an isotopic clock. Oecologia 2008; 157:41-52. [DOI: 10.1007/s00442-008-1045-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 04/11/2008] [Indexed: 11/29/2022]
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Abstract
The depth of a cell of a multicellular organism is the number of cell divisions it underwent since the zygote, and knowing this basic cell property would help address fundamental problems in several areas of biology. At present, the depths of the vast majority of human and mouse cell types are unknown. Here, we show a method for estimating the depth of a cell by analyzing somatic mutations in its microsatellites, and provide to our knowledge for the first time reliable depth estimates for several cells types in mice. According to our estimates, the average depth of oocytes is 29, consistent with previous estimates. The average depth of B cells ranges from 34 to 79, linearly related to the mouse age, suggesting a rate of one cell division per day. In contrast, various types of adult stem cells underwent on average fewer cell divisions, supporting the notion that adult stem cells are relatively quiescent. Our method for depth estimation opens a window for revealing tissue turnover rates in animals, including humans, which has important implications for our knowledge of the body under physiological and pathological conditions. All the cells in our body are descendants of a single cell – the fertilized egg. Some cells are relatively close descendants, having undergone a small number of cell divisions, while other cells may be hundreds or even thousands of divisions deep. So far, science was unable to provide even gross estimates for the depths of the vast majority of human and mouse cells. In this study, we show that precise depth estimates of cells can be obtained from the analysis of non-hazardous mutations that spontaneously accumulate during normal development. The concept behind the method is simple: deeper cells tend to acquire more mutations and “drift away” from the original DNA sequence of the fertilized egg. Knowing how deep cells are is the key to many fundamental open questions in biology and medicine, such as whether neurons in our brain can regenerate, or whether new eggs are created in adult females.
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Stegall VK, Farley SD, Rea LD, Pitcher KW, Rye RO, Kester CL, Stricker CA, Bern CR. Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus). CAN J ZOOL 2008. [DOI: 10.1139/z07-115] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knowledge of diet–tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared δ13C and δ15Ν οf paired serum and vibrissal roots with those of ingested milk (n = 52) from free-ranging Steller sea lion ( Eumetopias jubatus (Schreber, 1776)) pups (1–11 months) and juveniles (14–27 months) to estimate diet–tissue discrimination. Mean 15N enrichment from ingested milk to serum was 2.1‰ ± 0.6‰ and δ15Ν at the root of the vibrissae (representing current growth) were not significantly different from serum values. Milk was enriched for mean 13C by 5.0‰ ± 1.0‰ and 7.3‰ ± 1.2‰ relative to serum and vibrissal roots, respectively, which was due to the presence of 13C-depleted lipids in milk. This was confirmed by lipid extraction from a subset of milk and serum samples, resulting in a 5.8‰ ± 1.0‰ change only in milk. This study established that vibrissal roots and serum are reflective of a milk diet with approximately 2.0‰ 15N enrichment, and vibrissal roots reflect serum and lipid-extracted milk values with approximately 2.0‰ 13C enrichment. These discrimination factors are important to establish for stable isotope studies assessing diet shifts.
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Affiliation(s)
- Vicki K. Stegall
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Sean D. Farley
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Lorrie D. Rea
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Kenneth W. Pitcher
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Robert O. Rye
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Cynthia L. Kester
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Craig A. Stricker
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
| | - Carleton R. Bern
- Alaska Department of Fish and Game, Division of Wildlife Conservation, P.O. Box 757220, Fairbanks, AK 99775, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518, USA
- Alaska Department of Fish and Game, Division of Wildlife Conservation, 525 West 67th Avenue, Anchorage, AK 99518, USA
- United States Geological Survey, Stable Isotope Laboratory, Denver Federal Center, Building 21, Mail Stop 963, Denver, CO 80225, USA
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CRAWFORD KERRY, MCDONALD ROBBIEA, BEARHOP STUART. Applications of stable isotope techniques to the ecology of mammals. Mamm Rev 2008. [DOI: 10.1111/j.1365-2907.2008.00120.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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