The causes and consequences of intraspecific variation in standard metabolic rate

标准代谢率种内变异的原因和后果

• 批准号: NE/F019165/1
• 负责人: Neil Metcalfe
• 金额: $ 41.56万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF019165%2F1
• 关键词: causes; consequences; intraspecific; variation; standard

Why does substantial variation between individuals in their physiology persist, when it appears to have a significant effect on viability? One explanation for the maintenance of individual variation in a key trait is that it is non-genetic in origin and is created by environmental or maternal influences, but the direct evidence for this is often weak. This project will investigate the causes / and also the consequences / of variation between individuals in their minimal rate of metabolism, generally termed basal or standard metabolic rate (SMR). SMR varies considerably between (but is consistent within) individual animals and has major effects on performance: in salmonid fish, for example, an individual's SMR when a fry is a significant predictor of its dominance status, future growth and survival rate, as well as being a major influence on the efficiency of growth. However, the heritability of SMR is low. Why, then, is there so much phenotypic variation in SMR? Here we put forward the hypotheses that different environments favour different rates of metabolism, and that rates of metabolism are programmed by embryonic exposure to maternal steroid hormones (testosterone and cortisol) in the egg. Using trout as a study system, we will test novel predictions that arise from this hypothesis by means of experiments on both breeding adults and their offspring in a range of rearing conditions. We will test by means of hormone manipulations whether a mother's hormone levels at the time of spawning affect metabolic rates in her fry and whether eggs from different parts of the ovary receive different levels of hormone, so generating variation in metabolic rate (and aggression) within the offspring. We will also test whether the best metabolic rate (high or low) depends on the microhabitat in which the fish is living, so providing an explanation for the persistence of this variation. The information gathered will provide an understanding of the causes and consequences of variation in this basic physiological trait and of the role that hormones play as a maternal tool for adjusting offspring to the environment, so linking endocrinology, ecophysiology, behaviour and populations. The results will have relevance for studies of local adaptation and population structure, but also fish welfare and the design of husbandry regimes.

为什么个体之间在生理上的巨大差异会持续存在，当它似乎对生存能力有重大影响时？一个关键性状的个体变异得以维持的解释是，它的起源不是遗传的，而是由环境或母体影响造成的，但这方面的直接证据往往很薄弱。该项目将调查个体之间最低代谢率（通常称为基础或标准代谢率（SMR））变化的原因和后果。SMR在个体动物之间变化很大（但在个体动物内部是一致的），并对性能产生重大影响：例如，在鲑鱼中，当鱼苗时，个体的SMR是其优势地位，未来生长和存活率的重要预测因素，并且对生长效率产生重大影响。然而，SMR的遗传力较低。那么，为什么SMR中有如此多的表型变异呢？在这里，我们提出的假设，不同的环境有利于不同的代谢率，代谢率是由胚胎暴露于母体类固醇激素（睾酮和皮质醇）在鸡蛋。使用鳟鱼作为一个研究系统，我们将测试新的预测，从这个假设所产生的繁殖成人和他们的后代在一系列饲养条件下的实验手段。我们将通过激素操作来测试母亲在产卵时的激素水平是否会影响她的鱼苗的代谢率，以及卵巢不同部位的卵子是否会接受不同水平的激素，从而在后代中产生代谢率（和侵略性）的变化。我们还将测试最佳代谢率（高或低）是否取决于鱼所生活的微生境，从而为这种变化的持续性提供解释。所收集的信息将有助于了解这一基本生理特征变化的原因和后果，以及激素作为母亲调整后代适应环境的工具所发挥的作用，从而将内分泌学、生态生理学、行为学和种群联系起来。研究结果将与当地适应性和种群结构的研究有关，也与鱼类福利和畜牧业制度的设计有关。

项目成果

Relationship between oxidative stress and circulating testosterone and cortisol in pre-spawning female brown trout.

产卵前雌性褐鳟氧化应激与循环睾酮和皮质醇的关系。

• DOI: 10.1016/j.cbpa.2012.07.002
• 发表时间: 2012
• 期刊: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology
• 作者: Hoogenboom MO