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Unravelling the Nitrogen Isotope Signal of Skeletal Collagen for Palaeodeitary Reconstruction: The Origin of the Nitrogen Isotope Trophic Level Effect

解开用于古生殖重建的骨骼胶原蛋白的氮同位素信号：氮同位素营养水平效应的起源

基本信息

批准号：
NE/J010510/1
负责人：
Richard Evershed
金额：
$ 42.56万
依托单位：
University of Bristol
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ010510%2F1
关键词：
Unravelling Nitrogen Isotope Signal Skeletal

项目摘要

When an organism eats it digests the biochemical components of the food to either grow new tissues or derive energy to sustain itself. In doing this the major elements, e.g. C and N, from the different parts of the diet are incorporated into the tissues of the consumer organism. This has given rise to the adage "you are what you eat". More than 30 years ago researchers realised that the stable isotopic compositions of the major elements making up the nutrients in the diet namely, 13C/12C and 15N/14N, vary between different plants and animals as a result of such factors as the differing biosynthetic and metabolic pathways giving rise to different biochemical components or the differing stable isotope compositions of the C and N sources at the base of food chains. The above phenomena gave rise to an ingenious new way of studying the diets of fossil organisms, including prehistoric humans. Stable C and N isotope signatures of preserved biochemicals in skeletal remains from archaeological sites were compared with the stable isotope values of potential foods, allowing the diet of the consumer to be inferred. The new discipline has the title "palaeodietary reconstruction". A major reason for the success of this new field was the fact that the major structural skeletal protein, collagen, has been found to be widely preserved in ancient skeletal remains many 1000s of years old. A major observation is that the N isotope value of an organism is higher than its diet. This phenomenon is termed the "trophic level effect". Thus, the N isotope value of herbivores are higher than that of the plants they eat, and the N isotope value of a carnivore is higher than that of the herbivores it eats. Hence, N isotope value of a human, will lie somewhere in between the values of the plants and animals he or she eats. Remarkably, although this effect has been used in research reported in several thousand publications, the underlying mechanics of N trophic enrichment within the amino acids (AAs) that comprise the major body proteins are unknown. The aim of our research is to bridge this knowledge gap. Until recently the same problem existed for C isotopes but this gap in knowledge has begun to be filled as a result of us exploiting a range of new analytical techniques which allow the C isotope compositions of individual compounds to be recorded at high precision. In the case of the structural protein collagen this involves breaking it down to its constituent AAs, from which their C isotope compositions can be determined, revealing the origin of the collagen C isotope signal. Through this approach we have revealed how C is incorporated from different dietary macronutrients and identified dietary components which would not have been seen using whole collagen measurements. The aim of this new project is to undertake analogous analyses of the N isotope compositions of the AAs that make up structural proteins. N isotope analyses are technically very difficult to perform; however, we recently published the first systematic determinations of AA N isotopes for prehistoric humans and their diets. We will apply this approach to provide the necessary understanding of the N tropic effect by analysing the AA components of the proteins in various tissues of animals and their diets, including those derived from: (i) a unique controlled pig feeding experiment (pigs being accepted as excellent animal models for humans) in which the animals were raised on both plant and animal protein based diets, (ii) tissue culture experiments which will allow cellular and whole organism effects to be resolved for the first time, (iii) key organisms sampled from marine food webs, which are particularly interesting as they express the N trophic effect most strongly, and (iiv) a range of archaeological human and animal skeletal remains from regions where varying amounts of marine and terrestrial foods would have been consumed, to reveal population level variation.

当有机体进食时，它会消化食物中的生化成分，以生长新的组织或获取能量来维持自身。在此过程中，主要要素，例如来自饮食不同部分的 C 和 N 被纳入消费者有机体的组织中。这就产生了“你吃什么就是什么”这句格言。 30多年前，研究人员认识到，构成饮食中营养素的主要元素（13C/12C和15N/14N）的稳定同位素组成在不同植物和动物之间存在差异，这是由于不同的生物合成和代谢途径导致不同的生化成分或食物链底部的C和N源的稳定同位素组成不同等因素造成的。上述现象催生了一种研究化石生物（包括史前人类）饮食的巧妙新方法。将考古遗址骨骼遗骸中保存的生化物质的稳定 C 和 N 同位素特征与潜在食物的稳定同位素值进行比较，从而推断消费者的饮食。新学科的名称是“古饮食重建”。这一新领域成功的一个主要原因是，人们发现主要的结构骨骼蛋白——胶原蛋白广泛保存在数千年前的古代骨骼遗骸中。一个主要观察结果是生物体的 N 同位素值高于其饮食。这种现象被称为“营养级效应”。因此，食草动物的N同位素值高于其所吃的植物的N同位素值，而食肉动物的N同位素值则高于其所吃的草食动物的N同位素值。因此，人类的 N 同位素值将介于他或她所吃的植物和动物的值之间。值得注意的是，尽管这种效应已在数千篇出版物中报道的研究中得到应用，但组成主要身体蛋白质的氨基酸 (AA) 内氮营养富集的基本机制尚不清楚。我们研究的目的是弥合这一知识差距。直到最近，C 同位素也存在同样的问题，但由于我们开发了一系列新的分析技术，可以高精度记录单个化合物的 C 同位素组成，这一知识空白已开始得到填补。就结构蛋白胶原而言，这涉及将其分解为其成分 AA，从中可以确定其 C 同位素组成，从而揭示胶原 C 同位素信号的起源。通过这种方法，我们揭示了如何从不同的膳食常量营养素中吸收碳，并确定了使用全胶原蛋白测量无法看到的膳食成分。这个新项目的目的是对构成结构蛋白的 AA 的 N 同位素组成进行类似分析。 N 同位素分析在技术上很难进行；然而，我们最近发表了对史前人类及其饮食的 AA N 同位素的首次系统测定。我们将应用这种方法，通过分析动物不同组织及其饮食中蛋白质的 AA 成分，来提供对 N 热带效应的必要了解，包括源自：(i) 独特的受控猪饲养实验（猪被认为是人类优秀的动物模型），其中动物以植物和动物蛋白为基础的饮食饲养，(ii) 组织培养实验，该实验将允许解决细胞和整个有机体的影响首次，（iii）从海洋食物网中采样的关键生物体，它们特别有趣，因为它们最强烈地表达氮营养效应，以及（iii）来自不同数量的海洋和陆地食物消耗地区的一系列考古人类和动物骨骼遗骸，以揭示种群水平的变化。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The influence of varying proportions of terrestrial and marine dietary protein on the stable carbon-isotope compositions of pig tissues from a controlled feeding experiment

控制饲养实验中不同比例的陆地和海洋膳食蛋白质对猪组织稳定碳同位素组成的影响

DOI：
10.1080/20548923.2016.1275477
发表时间：
2017
期刊：
Science & Technology of Archaeological Research
影响因子：
3.5
作者：
Webb E
通讯作者：
Webb E

Compound-specific amino acid isotopic proxies for distinguishing between terrestrial and aquatic resource consumption

DOI：
10.1007/s12520-015-0309-5
发表时间：
2018-02
期刊：
Archaeological and Anthropological Sciences
影响因子：
2.2
作者：
E. Webb;Noah V. Honch;P. Dunn;Anna Linderholm;Gunilla Eriksson;K. Lidén;R. Evershed
通讯作者：
E. Webb;Noah V. Honch;P. Dunn;Anna Linderholm;Gunilla Eriksson;K. Lidén;R. Evershed

Age effects and the influence of varying proportions of terrestrial and marine dietary protein on the stable nitrogen-isotope compositions of pig bone collagen and soft tissues from a controlled feeding experiment

受控饲养实验的年龄效应以及不同比例的陆地和海洋膳食蛋白质对猪骨胶原和软组织稳定氮同位素组成的影响