Testing the ecological relevance of the heat dissipation limit hypothesis in a small mammal

测试小型哺乳动物散热极限假说的生态相关性

• 批准号: NE/C004159/1
• 负责人: John Speakman
• 金额: $ 41.61万
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FC004159%2F1
• 关键词: Testing; ecological; relevance; heat; dissipation

Everything that animals do behaviourally and physiologically requires energy. However, while there are lots of things energy can be expended on, there is only one source of that energy / food intake. If animals could eat process and expend unlimited quantities of energy there would be no problem, but of course they can't, which leads to leading to important trade-offs between competing demands within the total available budget. The maximal rate at which energy can be ingested is called the Sustained energy intake or SusEI. I have been working on the limits to SusEI and its wider ramifications for about 10 years and we have recently made a significant breakthrough in our understanding these limits. The current proposal builds on this important advance. To set this advance in context it is necessary to provide some background to the research area. Two ideas were proposed in the early 1990s concerning how limits to SusEI might be mediated. Limits might be imposed by the capacity of the alimentary tract and associated organs (the central limits hypothesis) or imposed at sites where the energy is utilised (the peripheral limits hypothesis). Over the past two years we have been working on a radically different idea, and our findings were published last year in a series of three papers in the Journal of Experimental Biology. Our hypothesis draws on agricultural observations that the performance of dairy cows is significantly affected by their capacity to dissipate heat generated during lactation. Observations we have made in laboratory mice are consistent with the hypothesis that mice similarly constrained in their capacity to dissipate heat / the heat dissipation limit hypothesis. There is, however, a problem. Laboratory mice have been selected for unusually high offspring productivity. Although the heat dissipation limitation hypothesis explains our observations in this model system, for wild small mammals, which have smaller litters, this limitation may never be reached. Establishing the ecological relevance of our observations is therefore critical before we can explore the wider ramifications of this finding. The current proposal involves work that will establish the ecological relevance of this breakthrough in our understanding of limits on SusEI of laboratory mice, therefore potentially enabling a broad spectrum of future studies. Because of the pivotal importance of SusEI, we have been able in the past to use studies of it to provide significant insights into a range of fundamentally important ecological questions. For example, understanding how climate changes influence animal distributions (Thomas, Blondell and Speakman 2001; Science; Humphries, Thomas and Speakman, 2002 Nature) and why kleptoparasitism has such an important effect on the population biology of African wild-dogs (Gorman et al 2001: Nature). The implications of understanding what limits SusEI also stretch to many other areas, including understanding the evolution of endothermy (Bennett and Ruben, 1989; Science Hayes and Garland,1996; Physiol Zool.) and the regulation of energy balance and obesity (eg Speakman et al 2002: Proc Nut Soc).

动物在行为上和生理上所做的一切都需要能量。然而，虽然有很多东西可以消耗能量，但只有一种能量来源/食物摄入。如果动物可以食用加工过程并消耗无限量的能量，那就没有问题，但它们当然不能，这就导致了在总可用预算内竞争需求之间的重要权衡。能量可以被摄入的最大速率被称为持续能量摄入或SusEI。10年来，我一直在研究SusEI的限制及其更广泛的影响，最近我们在理解这些限制方面取得了重大突破。目前的提案建立在这一重要进展的基础上。为了将这一进展置于背景中，有必要为研究领域提供一些背景。20世纪90年代初，关于如何调解对SusEI的限制，提出了两个想法。限制可能是由消化道和相关器官的容量施加的（中心限制假说），也可能是在能量被利用的部位施加的（外围限制假说）。在过去的两年里，我们一直在研究一个完全不同的想法，我们的发现去年发表在《实验生物学杂志》（Journal of Experimental Biology）上的三篇系列论文中。我们的假设借鉴了农业观察，奶牛的生产性能受到它们在哺乳期间产生的热量的耗散能力的显著影响。我们在实验室老鼠身上所做的观察与老鼠同样受到散热能力限制的假设一致/散热极限假设。然而，这里有一个问题。选择实验室老鼠是因为它们的后代繁殖能力非常高。尽管散热限制假说解释了我们在这个模型系统中的观察结果，但对于产仔较少的野生小型哺乳动物来说，这个限制可能永远不会达到。因此，在我们探索这一发现的更广泛影响之前，建立我们观察结果的生态相关性至关重要。目前的提案涉及的工作将建立我们对实验室小鼠SusEI限制的理解的这一突破的生态相关性，因此可能会使未来的研究范围更广。由于SusEI的关键重要性，我们过去已经能够通过对它的研究，为一系列根本性的重要生态问题提供重要的见解。例如，了解气候变化如何影响动物分布（Thomas, Blondell and Speakman 2001; Science; Humphries, Thomas and Speakman, 2002 Nature），以及为什么盗寄生对非洲野狗的种群生物学有如此重要的影响（Gorman et al 2001: Nature）。了解限制SusEI的含义也延伸到许多其他领域，包括了解恒温动物的进化（Bennett和Ruben, 1989； Science Hayes和Garland,1996; Physiol Zool.）和能量平衡和肥胖的调节（例如Speakman等人2002:Proc Nut Soc）。

项目成果

Limits to sustained energy intake XXIV: impact of suckling behaviour on the body temperatures of lactating female mice.

• DOI: 10.1038/srep25665
• 发表时间: 2016-05-09
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Gamo Y;Bernard A;Troup C;Munro F;Derrer K;Jeannesson N;Campbell A;Gray H;Miller J;Dixon J;Mitchell SE;Hambly C;Vaanholt LM;Speakman JR
• 通讯作者: Speakman JR

A trade-off between current and future sex allocation revealed by maternal energy budget in a small mammal.

小型哺乳动物的母体能量预算揭示了当前和未来性别分配之间的权衡。

• DOI: 10.1098/rspb.2010.2654
• 发表时间: 2011
• 期刊: Proceedings. Biological sciences
• 作者: Rutkowska J