Genes, environment, and plasticity in C. elegans behaviour

环境在变化，为了生存，有机体必须有适应这些变化的机制。由于环境条件在不同的时间尺度上是可变的，自适应塑性机制也必须在它们运行的时间尺度上有所不同。例如，生理变化有助于适应24小时昼夜循环中发生的温度波动，而温度的季节性波动可能与毛皮的生长或脱落有关，或与冬眠等戏剧性的新陈代谢变化有关。随着物种范围的扩大或改变或整体气候的变化，进化推动了种群的适应性变化。本研究计划重点研究线虫秀丽线虫的觅食行为。我们研究线虫是因为它作为模型系统的优势，特别是分析行为的遗传和神经基础的一套可扩展的工具。觅食行为在行为学和行为神经科学中特别有吸引力，因为有成熟的概念模型帮助预测给定特定环境或一组经验时，最佳觅食者应该如何行为。这个项目的目标是了解觅食策略的变异和可塑性是如何在不同的时间尺度上运作的。基于摄食状态和食物可获得性的短期觅食调节在线虫中得到了广泛的研究。我们感兴趣的是更长期的可塑性形式：由适应性发育可塑性调节的整个生命的时间尺度(对于线虫来说，数天)，通过跨代表观遗传在几周内的过程，以及适应不同当地条件的野生种群之间的差异。目的1.觅食可塑性的遗传基础。我们最近的工作发现了与驯化相关的觅食行为变化的遗传基础，这与野生分离物之间的站立变异不同。我们将使用一组测序的菌株来识别在野生分离株中产生不同觅食策略的遗传和行为变异。目的2.季节适应与跨代可塑性。多个小组已经确定了由小RNA遗传介导的对行为和生理的跨代影响，所有这些影响都持续到5-7代的数量级。我们将测试一种假设，即这是一种与温带气候中与季节性进展相关的环境变化相适应的机制。目标3.在自然环境中探索、分散和适应。在最长的时间尺度上，进化驱动种群的适应性遗传变化。在这里，我们将使用大型的、设计的环境来测试长期实验进化实验中关于扩散和觅食与适合性的预测。

Environments change, and in order to survive organisms must have mechanisms to adapt to these changes. Because environmental conditions are variable on different time scales, adaptive plasticity mechanisms must also vary in the time scales on which they operate. For example, physiological changes can help adjust to temperature fluctuations that occur over the 24-hour day/night cycle, while seasonal fluctuations in temperature might be associated with growing or losing fur, or dramatic metabolic changes like hibernation. As species expand or change their range or the overal climate shifts, evolution drives adaptive changes in populations. This research program focuses on foraging behaviour in the nematode Caenorhabditis elegans. We study C. elegans because of its advantages as a model system, particularly the expansive set of tools for analyzing the genetic and neural basis of behaviour. Foraging behaviours are especially attractive in ethology and behavioural neuroscience because there are well-developed conceptual models that help make predictions about how an optimal forager should behave given a particular environment or set of experiences. The goal of this program is to understand how variation and plasticity in foraging strategies operates across various time scales. Short-term regulation of foraging based on feeding state and food availability has eben extensively studied in C. elegans. Our interests are in longer-term forms of plasticity: the time scales of an entire life (days, for a nematode) mediated by adaptive developmental plasticity, over the course of weeks via transgenerational epigenetic inheritance, and variation between wild populations that have adapted to different local conditions. Aim 1. The genetic basis of foraging plasticity. Our recent work identified the genetic basis of domestication-associated changes in foraging behaviour, which differs from the standing variation among wild isolates. We will using a panel of sequenced strains to identify genetic and behavioural variation that produces different foraging strategies in wild isolates. Aim 2. Seasonal adaptation and transgenerational plasticity. Multiple groups have identified transgenerational effects on behaviour and physiology that are mediated by small RNA inheritance, all of which last on the order of 5-7 generations. We will test the hypothesis that this is a mechanism tuned to environmental changes associated with seasonal progression in temperate climates. Aim 3. Exploration, dispersal, and fitness in naturalistic environments. On the longest time scale, evolution drives adapative genetic changes in populations. Here, we will use large, designed environments to test predictions about dispersal and foraging with respect to fitness in long-term experimental evolution experiments.