How do animals cope with stress in different environments? (Ref 4595)

项目背景我们知道，所有生物体都有一个应激反应系统来科普环境挑战，但其精确形式在个体内部和个体之间存在巨大差异。从本质上讲，压力反应系统应该能够对压力源做出反应（战斗，逃跑），但同时它应该尽量减少对动物其他生理系统的干扰。最近，我们发现压力源的可预测性可能是压力反应变化的主要驱动力。本项目进一步验证了这一假设。您将接受计算机编程和建模技术（如控制理论）的培训，以预测压力反应系统在不同环境中发展的关键特征和限制。然后，我们把这些模型的压力预测性的测试，通过使用实验室实验和实地工作在地中海场蟋蟀Gryllus bimaculatus.Project的目的和MethodsBelow我们建议这个博士项目的三个潜在的组成部分，研究动物的压力反应的演变。当然，我们鼓励您考虑更接近您兴趣的不同组件，因为我们认为博士生应该领导他们项目的设计。1.压力反应系统的进化模型在项目的这一部分，您将接受生物学数学建模的培训，在那里您将学习如何使用控制理论来开发压力反应的进化模型。然后，你可以使用这些技能来分析压力反应系统的特征，这些特征会在压力源发生时经历波动。然后，这些模型允许人们预测压力反应系统的关键特征（例如，鲁棒性、损伤累积）随不同环境而变化。此外，它们还可以告诉我们条件的变化（例如，医疗干预，慢性压力）影响压力反应。实验测量压力源的可预测性如何影响压力反应蟋蟀是研究压力反应的一个很好的模式生物，因为潜在的压力反应途径开始被发现，其基因组最近已经测序。我们将使蟋蟀暴露于表明捕食的信号（例如，捕食者的气味，如普通蟾蜍）。应激反应是通过诸如章鱼胺的激素来测量的，章鱼胺是昆虫应激激素途径的关键组分。现有的模型表明，可预测与随机发生的压力源应影响的压力反应的大小。在该项目的这一部分中，我们的目标是通过比较不同的治疗组来测试这一预测，这些治疗组在发育过程中压力源发生与不存在的可预测性方面存在差异。3.在葡萄牙的蟋蟀种群中自然发生的压力源的实地工作我们的目的是比较在葡萄牙的Gryllus bimaculatus，不同的组成和密度的捕食者的实地种群的压力反应。此外，我们还可以通过使用保护笼来实验性地操纵压力源的发生，这些保护笼可以阻止关键的捕食者，如蛇，蟾蜍和老鼠。

Project BackgroundWe know that all organisms have a stress response system to cope with environmental challenges, yet its precise form varies hugely within and between individuals. At its heart, a stress response system should be able to throw everything at responding to a stressor (fighting, fleeing), but at the same time it should minimise disruption to the animal's other physiological systems. Recently, we have identified that stressor predictability is likely to be a major driver of variation in stress responses. This project further examine this hypothesis. You will be trained in computer programming and modelling techniques (such as control theory) to predict what key features and limitations of stress response systems evolve across different environments. We then put these models on stressor predictability to the test by using lab experiments and field work in the Mediterranean field cricket Gryllus bimaculatus.Project Aims and MethodsBelow we suggest three potential components of this PhD project to study the evolution of stress responses in animals. Of course, we encourage you to think about different components that are closer to your interests, as we believe that PhD students should lead the design of their projects. 1. Evolutionary models of stress response systems In this part of the project you will receive training in mathematical modelling in biology, where you will learn how to use control theory to develop an evolutionary model of a stress response. You can then use these skills to analyze what features characterize stress response systems that experience fluctuations in stressor occurrence. These models then allow one to predict how key features of stress response systems (e.g., robustness, damage accumulation) vary with different environments. Moreover, they also can inform us how changes in condition (e.g., medical interventions, chronic stress) affect the stress response.2. Experimentally measure how stressor predictability affects the stress response Crickets are a great model organism to the study of stress responses as the underlying stress response pathways are starting to be discovered and its genome has recently been sequenced. We will expose crickets to signals that indicate predation (e.g., scent of predators like the common toad). Stress responses are measured through hormones such as octopamine, which is a key component of the insect stress hormone pathway. Existing models made by us show that predictable vs random occurrences of stressors should affect the magnitude of the stress response. In this part of the project we aim to test this prediction by comparing different treatment groups that vary in the predictability of stressor occurrence vs absence during development.3. Field work on naturally occurring stressors in cricket populations in Portugal We aim to compare stress responses in field populations of Gryllus bimaculatus across Portugal, which differ in composition and density of predators. Moreover, we can also experimentally manipulate stressor occurrence by using protective cages that keep out key predators such as snakes, toads and mice.