Carbon, nitrogen, and sulfur diet–tissue discrimination in mouse tissues

Abstract

Stable-isotope ratios are increasingly being used to examine ecological questions pertaining to dietary choices, physiological status, and animal migration. It has been shown that animal tissues reflect the isotopic signature present in food, altered by a small reproducible fractionation value. The average diet–tissue discrimination for δ13C and δ15N is approximately 1‰ and 3‰, respectively, although the degree of diet–tissue discrimination may be affected by a range of factors and vary between organisms and tissue types. Although the average δ34S is approximately zero, the sulfur diet–tissue discrimination values have only been determined for a few organisms. It is necessary to determine accurate diet–tissue discrimination values between tissue and dietary components to have confidence in any food-web study or determination of diet quality. In this paper, we determine carbon, nitrogen, and sulfur diet–tissue discrimination values for whole blood, liver, skeletal muscle, heart, brain, and fat (carbon only) from adult mice (Mus musculus L., 1758) equilibrated on three diets with unique isotopic signatures for carbohydrate carbon and for protein carbon, nitrogen, and sulfur. These data will aid researchers in choosing tissues to be used to examine food-web changes over time.

Tissue–diet discrimination factors and turnover of stable carbon and nitrogen isotopes in white-footed mice (Peromyscus leucopus)

“…However, the mean d 15 N value of the liver was approximately 4.5% higher than that of the initial diet and significantly higher than the other tissues sampled. This increase in the d 15 N value of liver over other tissues has been reported by Arneson and MacAvoy (2005) and MacAvoy et al (2005), and suggests a differential fractionation of nitrogen occurring in liver tissue. Protein utilization exceeds dietary intake by approximately five times, because there is significant recycling of protein during synthesis of metabolically active tissues (Ayliffe et al 2004).…”

Sulphur-isotope compositions of pig tissues from a controlled feeding study

“…This technological improvement has resulted in an increase in the use of sulphur stable isotope analyses for palaeodietary reconstruction, migration, and ecological research. For example, δ 34 S values have been used to distinguish between marine and terrestrial resource consumption, assess the interaction between terrestrial and estuarine environments, disentangle terrestrial, freshwater and marine resource contributions to diet in complex ecosystems, and to elucidate migration and residential proximity to the sea (inter alia, Arneson and MacAvoy, 2005;Craig et al, 2006;Howcroft et al, 2012;Nehlich, 2015;Nehlich et al, 2010Nehlich et al, , 2011Oelze et al, 2012aOelze et al, , 2012bPrivat et al, 2007;Richards et al, 2001Richards et al, , 2003Sayle et al, 2013;Valenzuela et al, 2011;Wilson et al, 2007).…”

“…Studies using, for example, invertebrates (e.g., McCutchan et al, 2003), fish (e.g., Barnes and Jennings, 2007) and ruminants (e.g., Tanz and Schmidt, 2010) as animal models, although valuable in their field, are of limited use for human palaeodietary reconstruction. More relevant feeding experiments using pigs (Gonzalez-Martin et al, 2001), horses (Richards et al, 2003) and mice (Arneson and MacAvoy, 2005) have been hampered by small sample sizes or few replicates per dietary group, and have not included the investigation of archaeologically-relevant tissues (i.e., bone collagen). With the increasing use of sulphur isotopic analysis for palaeodiet reconstruction in complex ecosystems, further research using a larger sample sizes, a more appropriate animal model, and multiple consumer tissues and excreta is needed.…”

“…Arneson and MacAvoy (2005) observed inter-tissue differences in the degree of 34 S-enrichment or depletion relative to diet for mice, and Richards et al (2003) determined that tail hair keratin was 34 S-depleted relative to diet (∼−1.0 ‰) for horses (n=1). Arneson and MacAvoy (2005) also compared sulphur isotopic compositions for mice consuming a terrestrial protein-based diet (casein, beet sucrose and soybean oil) and mice consuming a marine protein-based diet (fish meal, cane sucrose and soybean oil). They determined that mice tissues were slightly 34 S-depleted relative to the terrestrial protein diet and slightly 34 S-enriched relative to the marine protein diet.…”

Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients

“…In life sciences, sulfur isotopic ratios are mainly used to trace animals' diet in wildlife (13) and in stockbreeding (14) contexts. To this date, one study reports on bodily sulfur isotopic systematics, which shows no significant variations relative to diet in a murine model (15).…”