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

虽然睡眠在整个动物界几乎是普遍存在的，但不同物种的睡眠模式和睡眠时间差异很大。此外，个体还会根据所处的环境改变他们的睡眠时间。虽然调节睡眠对动物的生存可能很重要，但人们对这种睡眠行为的可塑性是如何演变的知之甚少。影响动物睡眠时间长短的一个生态因素是食物供应。一些物种减少睡眠是为了应对食物匮乏的环境，估计是为了增加觅食的时间。然而，其他人在这些情况下增加睡眠，这可能是一种在没有食物时节省能量的策略。这被称为睡眠可塑性。这项研究以失明的墨西哥穴居鱼为研究对象，研究了睡眠可塑性的进化。通过量化洞穴鱼在自然栖息地的不同季节的睡眠，研究人员将把自然发生的、可变的环境条件与动物的睡眠数量联系起来。此外，还将在穴居鱼及其对应的表面鱼杂交后代中检查睡眠可塑性，从而检查睡眠可塑性的遗传基础。总之，这些研究将提供前所未有的见解，了解睡眠可塑性是如何以及为什么进化的，睡眠可塑性是如何受到环境变量影响的，以及潜在的基因对睡眠可塑性的影响。吸引人的洞穴鱼系统将通过为本科生开发研究密集型课程和为高中生开发暑期研究指导计划来吸引学生。最后，与FAU的Osher终身学习研究所的合作将促进退休公民对科学研究的了解，并为当地退休人员提供研究机会。组织根据环境因素调节睡眠，表现出睡眠的可塑性。睡眠可塑性的一个显著例子是在不同营养供应条件下观察到的睡眠变化。该项目旨在了解墨西哥洞穴鱼睡眠可塑性进化的遗传基础。在自由摄食的实验室条件下，穴居鱼的睡眠比同种的表层鱼要少。当饥饿时，表层鱼和洞穴鱼有相反的反应：表层鱼减少睡眠，而洞穴鱼增加睡眠。这项研究计划将检验这样一个假设，即洞穴鱼已经进化出睡眠不足并改变了睡眠可塑性，以应对洞穴环境的食物供应随季节的强烈变化。在不同的环境中，睡眠可塑性和进化之间的关系用三种方法来检验：1)将评估由多个洞穴种群产生的表面-洞穴杂交种和洞穴杂交种，以阐明睡眠可塑性背后的遗传结构，并确定这一特征进化的候选基因；2)将在三个不同的洞穴中进行跨季节的野外测量，以确定这些行为在自然栖息地中的行为，并确定这些行为进化的环境条件。3)将对同一洞穴内不同池塘中不同食物供应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。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.