Collaborative Research: The evolution of phenotypic plasticity in sleep across variable environments

虽然睡眠在动物王国中几乎是普遍存在的，但不同物种之间的睡眠模式和睡眠时间却存在巨大差异。此外，个人会根据环境改变睡眠时间。虽然调节睡眠对于动物的生存可能很重要，但人们对睡眠行为的可塑性如何演变知之甚少。影响动物睡眠时间的生态因素之一是食物供应。有些物种为了应对食物匮乏的环境而减少睡眠，大概是为了增加觅食的时间。然而，其他人在这些条件下会增加睡眠，这可能是在没有食物的情况下节省能量的策略。这被称为睡眠可塑性。这项工作以墨西哥盲眼洞穴鱼为焦点物种，研究了睡眠可塑性的演变。通过量化不同季节洞穴鱼在自然栖息地的睡眠，研究人员将自然发生的、可变的环境条件与动物的睡眠时间联系起来。此外，还将在洞穴鱼与其表层鱼类对应物的杂交中检查睡眠可塑性，从而检查睡眠可塑性的遗传基础。总之，这些研究将为睡眠可塑性如何以及为何进化、环境变量如何影响睡眠可塑性以及睡眠可塑性的潜在遗传影响提供前所未有的见解。迷人的洞穴鱼系统将通过开发本科生研究密集型课程和高中生暑期研究指导项目来吸引学生。最后，与佛罗里达州立大学奥舍终身学习研究所的合作将促进退休公民对科学研究的理解，并为当地退休人员提供研究机会。生物体根据环境因素调节睡眠，表现出睡眠可塑性。 睡眠可塑性的一个引人注目的例子是在不同营养可用性条件下观察到的睡眠变化。该项目旨在了解墨西哥穴居鱼 Astyanax mexicanus 睡眠可塑性进化的遗传基础。在随意喂食的实验室条件下，洞穴鱼的睡眠时间比同种地表鱼少。当饥饿时，水面鱼和洞穴鱼有相反的反应：水面鱼减少睡眠，而洞穴鱼增加睡眠。该研究计划将检验以下假设：洞穴鱼进化出了睡眠不足并改变了睡眠可塑性，以应对不同季节食物供应量差异很大的洞穴环境。使用三种方法检查可变环境中的睡眠可塑性和进化之间的关系：1）将评估由多个洞穴种群产生的地表洞穴杂交和洞穴洞穴杂交，以阐明睡眠可塑性的遗传结构，并识别该性状进化的候选基因，2）将在三个不同的洞穴鱼洞穴中跨季节测量睡眠、进食和食物可用性，以定义自然栖息地中的这些行为，并确定这些行为发生的环境条件。 3）将对同一洞穴内不同水池中食物供应量不同的鱼类进行基因组和行为分析，以揭示单个洞穴内行为进化的遗传基础。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

While sleep is almost universal across the animal kingdom, sleep patterns and amount vary drastically between species. Further, individuals alter how much they sleep in response to their environments. While modulating sleep is likely important for an animal's survival, little is known about how this plasticity in sleeping behavior evolves. One ecological factor that affects how much an animal sleeps is food availability. Some species reduce sleep in response to a food-poor environment, presumably to increase the time available for foraging. However, others increase sleep under these conditions, which is likely a strategy to conserve energy when food is not available. This is referred to as sleep plasticity. This work examines the evolution of sleep plasticity using the blind Mexican cavefish as a focal species. By quantifying sleep in cavefish in their natural habitats across seasons, the researchers will connect naturally occurring, variable environmental conditions to the amount animals sleep. Further, sleep plasticity will be examined in crosses derived from cavefish and their surface fish counterparts, allowing for examination of the genetic basis of sleep plasticity. Together, these studies will provide unprecedented insight into how and why sleep plasticity has evolved, how sleep plasticity is impacted by environmental variables, and the underlying genetic influences on sleep plasticity. The captivating cavefish system will be leveraged to engage students through the development of a research-intensive course for undergraduates and a summer research mentoring program for high school students. Finally, a collaboration with FAU's Osher Lifelong Learning Institute will promote understanding of scientific research for retired citizens and provide research opportunities for local retirees.Organisms regulate sleep in response to environmental factors, displaying sleep plasticity. One striking example of sleep plasticity is the change in sleep observed under different nutrient availability conditions. This project aims to understand the genetic basis of the evolution of sleep plasticity in the Mexican cavefish, Astyanax mexicanus. Cavefish sleep less than conspecific surface fish under ad libitum fed laboratory conditions. When starved, surface and cavefish have opposite responses: surface fish reduce sleep whereas cavefish increase sleep. This research program will test the hypothesis that cavefish have evolved sleep loss and altered sleep plasticity in response to a cave environment that strongly varies in food availability across seasons. The relationship between sleep plasticity and evolution in a variable environment are examined using three approaches: 1) surface-cave hybrids and cave-cave hybrids generated from multiple cave populations will be evaluated to elucidate the genetic architecture underlying sleep plasticity and to identify candidate genes for the evolution of this trait, 2) sleep, feeding, and food availability will be measured in the field across seasons in three different cavefish-containing caves to define these behaviors in natural habitats, and to determine the environmental conditions under which these behaviors have evolved, and 3) genomic and behavioral analyses will be performed on fish from different pools within the same cave that vary in food availability to uncover the genetic underpinnings of behavioral evolution within a single cave.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.