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，但不同物种的睡眠模式和睡眠时间却大相径庭。此外，个体还会根据环境改变睡眠时间。虽然调节睡眠可能对动物的生存很重要，但人们对睡眠行为的可塑性是如何进化的知之甚少。影响动物睡眠时间的一个生态因素是食物的可获得性。一些物种减少睡眠是为了应对食物匮乏的环境，大概是为了增加觅食的时间。然而，在这种情况下，其他人会增加睡眠时间，这可能是一种在没有食物时保存能量的策略。这被称为睡眠可塑性。这项工作研究了睡眠可塑性的进化，使用失明的墨西哥洞穴鱼作为焦点物种。通过量化洞穴鱼在不同季节的自然栖息地的睡眠，研究人员将把自然发生的、可变的环境条件与动物的睡眠量联系起来。此外，睡眠可塑性将在洞穴鱼和表层鱼的杂交中进行研究，从而研究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什么进化，睡眠可塑性如何受到环境变量的影响，以及潜在的遗传影响睡眠可塑性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计划来吸引学生。最后，与FAU的Osher终身学习研究所合作，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。生物体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条件下观察到的睡眠变化。该项目旨在了解墨西哥洞穴鱼（Astyanax mexicanus）睡眠可塑性进化的遗传基础。在实验室条件下，洞穴鱼的睡眠少于同类型的表层鱼。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。这个研究项目将测试洞穴鱼已经进化出睡眠不足和改变睡眠可塑性的假设，以应对洞穴环境在不同季节食物供应的强烈变化。在可变环境下，睡眠可塑性和进化之间的关系通过三种方法进行了检验：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，并确定这一特征进化的候选基因；2)将在三个不同的洞穴中测量不同季节的睡眠、摄食和食物供应，以定义自然栖息地中的这些行为；为了确定这些行为进化的环境条件，3)基因组和行为分析将对同一洞穴中食物供应不同的不同池中的鱼进行分析，以揭示单个洞穴中行为进化的遗传基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.