Collaborative Research: Keystone chemicals: Identifying general and universal molecules of fear

许多被捕食的物种利用捕食者尿液中释放的化学物质来检测迫在眉睫的危险并做出适当的反应，但这些“恐惧分子”的身份在很大程度上仍然未知。 该建议探讨是否猎物检测不同的河口捕食者使用相同的化学品或化学信号的身份是否不同。 实验重点是常见和重要的河口猎物，泥蟹和牡蛎，以及它们的捕食者，包括鱼类，甲壳类动物和海洋蜗牛。生物活性分子正在从捕食者和猎物中收集并表征。其目标是确定是否有预测之间的关系，无论是组成的猎物肉或捕食分类群和信号分子。了解这些线索的分子性质可以确定是否有一般规则管理可能的信号分子。一旦确定，研究人员将有能力在生态学或其他类型的研究中精确操纵或控制这些分子。牡蛎对河口的健康至关重要，是重要的社会、文化和经济资源。该项目的更广泛影响包括培训来自不同背景的本科生和研究生，并与水产养殖设施和保护管理人员合作，以改善牡蛎的生长和生存。对捕食者暗示的一种反应是制造更坚固的外壳来阻止捕食。确定牡蛎用来检测捕食者的线索的身份可以提供管理选择，以生产生长更快或更能抵抗捕食者的牡蛎。项目人员正在与牡蛎养殖者合作，通过管理化学线索来提高养殖牡蛎的产量。对于海洋猎物来说，水生化学线索是关于捕食威胁的重要信息来源，因此，在许多系统中调节捕食的非消耗性影响。通常，当捕食者吃掉猎物的肉时，就会产生这样的线索。在几乎所有的情况下，负责调节这些相互作用的特定生物活性分子都是未知的，这就提出了一个问题，即是否存在一种普遍的恐惧分子，猎物会对此做出反应。因此，该项目的重点是确定恐惧诱导代谢物释放的捕食者和猎物在河口食物网的一般性。该项目将饮食来源的尿液代谢物的代谢组学分析与生物测定相结合，以确定在来自不同分类组和营养级的两种猎物物种（牡蛎、泥蟹）中产生反应的生物活性分子。从三种类型的捕食者，鱼类，腹足类或甲壳类动物中取样。该项目旨在：1）确定生物活性分子产生的几个常见的河口捕食者从不同的类群; 2）比较线索，从捕食者诱导防御猎物与猎物行为的变化;和3）对比的身份和影响的捕食者释放的线索与恐惧诱导分子从受伤的同种。通过识别和对比水性分子的影响，诱导猎物的反应，从六个捕食者和受伤的猎物，这个项目产生的见解介导非致命的捕食者的影响的机制，同时解决长期存在的问题与捕食者-猎物的相互作用。除了寻找一个普遍的恐惧分子，实验正在探索的作用，互补的和独特的化学信息的特异性猎物的反应，不同类型的predator.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

Many prey species use chemicals released in predator urine to detect imminent danger and respond appropriately, but the identity of these ‘molecules of fear’ remains largely unknown. This proposal examines whether prey detect different estuarine predators using the same chemical or whether the identity of the chemical signals varies. Experiments focus on common and important estuarine prey, mud crabs and oysters, and their predators including fishes, crustaceans and marine snails. Bioactive molecules are being collected from predators and prey and characterized. The goal is to determine if there are predictive relationships between either the composition of prey flesh or the predator taxon and the signal molecule. Understanding the molecular nature of these cues can determine if there are general rules governing likely signal molecules. Once identified, investigators will have the ability to precisely manipulate or control these molecules in ecological or other types of studies. Oysters are critical to estuarine health, and they are important social, cultural and economic resources. Broader impacts of the project include training of undergraduate and graduate students from diverse backgrounds and working with aquaculture facilities and conservation managers to improve growth and survival of oysters. One response to predator cues involves creating stronger shells to deter predation. Determining the identity of cues used by oysters to detect predators can provide management options to produce oysters that either grow faster or are more resistant to predators. Project personnel is working with oystermen to increase yields of farmed oysters by managing chemical cues.For marine prey, waterborne chemical cues are important sources of information regarding the threat of predation, thus, modulating non-consumptive effects of predation in many systems. Often such cues are produced when the predators consume the flesh of that prey. In nearly all cases, the specific bioactive molecules responsible for modulating these interactions are unknown, raising the question whether there is a universal molecule of fear that prey respond to. Thus, the focus of the project is to determine the generality of fear-inducing metabolites released by predators and prey in estuarine food webs. The project combines metabolomics analysis of diet-derived urinary metabolites with bioassays to identify the bioactive molecules producing responses in two prey species from different taxonomic groups and trophic levels (oysters, mud crabs). Metabolites are sampled from three types of predators, fish, gastropods or crustaceans. This project aims to: 1) identify bioactive molecules produced by several common estuarine predators from different taxa; 2) compare cues from predators that induce defenses in prey vs. changes in prey behavior; and 3) contrast the identities and effects of predator-released cues with fear-inducing molecules from injured conspecifics. By identifying and contrasting the effects of waterborne molecules that induce prey responses from six predators and injured prey, this project is yielding insights into the mechanisms that mediate non-lethal predator effects, while addressing long-standing questions related to predator-prey interactions. In addition to the search of a universal molecule of fear, the experiments are exploring the role of complementary and distinct chemical information on the specificity of prey responses to different types of predators.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.