Genes, environment, and plasticity in C. elegans behaviour

环境在变化，为了生存，生物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，适应性可塑性机制在其运作的时间尺度上也必须是不同的。例如，生理变化可以帮助适应24小时昼夜循环中的温度波动，而温度的季节性波动可能与皮毛的生长或脱落有关，或者与冬眠等剧烈的代谢变化有关。当物种扩张或改变其活动范围或整体气候变化时，进化推动了种群的适应性变化。本研究项目主要研究秀丽隐杆线虫的觅食行为。我们研究秀丽隐杆线虫是因为它作为一个模型系统的优势，特别是用于分析行为的遗传和神经基础的扩展工具集。觅食行为在行为学和行为神经科学中特别有吸引力，因为有完善的概念模型，可以帮助预测在特定环境或一系列经历下，最佳觅食者应该如何表现。这个项目的目标是了解觅食策略的变化和可塑性是如何在不同的时间尺度上运作的。在秀丽隐杆线虫中，基于摄食状态和食物供应的短期觅食调节已被广泛研究。我们感兴趣的是长期形式的可塑性：整个生命的时间尺度（对线虫来说是几天）由适应性发育可塑性介导，在几周内通过跨代表观遗传，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。我们最近的工作确定了驯化相关的觅食行为变化的遗传基础，这种变化不同于野生分离株的直立变化。我们将使用一组测序菌株来确定在野生分离株中产生不同觅食策略的遗传和行为变异。目标2。季节适应和跨代可塑性。多个研究小组已经确定了小RNA遗传对行为和生理的跨代影响，所有这些影响都持续5-7代。我们将测试这一假设，即这是一种与温带气候的季节变化相关的环境变化机制。目标3。在自然环境中的探索、分散和适应。在最长的时间尺度上，进化推动了种群的适应性遗传变化。在这里，我们将使用大型设计环境来测试长期实验进化实验中关于适应性的分散和觅食的预测。

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.