Molecular determinants of host-feeding manipulation and microbial colonization

项目摘要 所有动物都生活在微生物包围的环境中，然而细菌对神经的影响 对系统的研究相对较少。最近的数据表明，共生肠道细菌可能能够 调节寄主行为。肠道细菌从它们的宿主消耗的营养中受益，因为这些 细菌必须主要通过食物传播，控制宿主的取食行为是一种主要的方式 哪些寄生微生物可以影响肠道微生物群落。由于这样的动态特性， 相互作用，在大多数系统中，研究取食操纵要么是具有挑战性的，要么是不可能的。 首先，我们必须确定宿主和微生物都能接受基因操作的系统，以及 这使得能够对定义的和自然的条件做出高通量的行为筛选。在这里，我们 建议在任何实验系统中首次全面研究这一现象，使用 线虫-与其自然伴生细菌相结合-获得机械洞察力 转化为驱动宿主-微生物相互作用和决策的有机体间信号。线虫是一种细菌- 一种食性线虫，常见于腐烂的植物材料中，通常由微生物寄生。C。 在所有多细胞生物中，线虫拥有一些最广泛的分子、神经生物学和遗传工具 真核生物，再加上在这些蠕虫中易于进行灵知生物培养，代表了一种非常有吸引力的 研究微生物对寄主行为影响的系统。 我最近证明，在线虫体内，肠道细菌可以影响化学感觉决定--一种替代 在特定环境下的进食行为--导致人们对这些食物产生的气味偏好增加 肠道微生物。在平行的前期工作中，我发现嗅觉可塑性对肠道定植的影响 在自然主义环境中，不同的微生物与肠道定植模式相关。总而言之，这些发现 提示线虫天然肠道微生物区系可能通过以下方式影响微生物组的组装 影响进食行为。在这项提案中，我们的目标是建立线虫作为研究摄食的系统 通过开发工具来识别影响微生物群结构的行为参数进行操作 自然主义的背景。我们建议通过实验将摄取从运动行为中分离出来 新型微流控成像设备的开发。我们将在2-和3-中开发新的行为分析 展示模拟蠕虫自然环境的微生物群落的次元领域。到时候我们会的 利用天然微生物鉴定嗅觉行为微生物依赖性改变的分子基础 社区。总之，我们建议开发肠道微生物喂养操纵的新领域，C。 优雅的人以杰出的模特为中心。我们预计，我们在这项提案中确定的原则应该 推广到多个系统，我们识别的神经活性化合物可能会影响 神经系统在不同的宿主中起作用。

Project Summary All animals live in environments surrounded by microbes, yet the impact of bacteria on nervous systems has been relatively under-studied. Recent data suggests that commensal gut bacteria may be capable of modulating host behavior. Gut bacteria benefit from nutrients consumed by their host and because these bacteria must be transmitted largely via diet, manipulation of host feeding behavior is a principal mode by which resident microbes can influence the gut microbial community. Due to the dynamic nature of such an interaction, studying feeding manipulation has been either challenging or impossible to date in most systems. First, we must identify systems in which both host and microbe are amenable to genetic manipulation, and which enable high-throughput behavioral screening in response to defined and naturalistic conditions. Here, we propose to comprehensively study this phenomenon for the first time in any experimental system, using the roundworm C. elegans — in combination with its natural associated bacteria — to gain mechanistic insights into inter-organismal signals driving host-microbe interactions and decision making. C. elegans is a bacterial- feeding nematode that is often found in rotting plant material and is commonly colonized by microbes. C. elegans has some of the most extensive molecular, neurobiological and genetic tools of any multicellular eukaryote, and, coupled with the ease of gnotobiotic culture in these worms, represents a highly attractive system in which to study microbial influence on host behavior. I have recently shown that in C. elegans, gut bacteria can influence chemosensory decisions — a proxy for feeding behavior in certain contexts — resulting in increased preference for odors produced by these enteric microbes. In parallel preliminary work, I have found that olfactory plasticity upon gut colonization by diverse microbes correlates with gut colonization patterns in naturalistic settings. Together, these findings suggest that the C. elegans native gut microbiota may be capable of impacting microbiome assembly by influencing feeding behavior. In this proposal, we aim to establish C. elegans as a system to study feeding manipulation by developing tools to identify the behavioral parameters which influence microbiome structure in naturalistic settings. We propose to experimentally isolate ingestion from locomotory behavior through the development of novel microfluidics imaging devices. We will develop new behavioral assays in 2- and 3- dimensional arenas to present microbial communities mimicking the worms’ natural environment. We will then identify the molecular basis of microbial-dependent changes in olfactory behaviors using naturalistic microbial communities. Together, we propose to develop a new field of feeding manipulation by gut microbes, with C. elegans centered as a preeminent model. We anticipate that the principles we identify in this proposal should generalize to multiple systems and the neuroactive compounds we identify have the potential to impact nervous system function in diverse hosts.