Study of Neuropeptide F Function in Drosophila

描述(申请人摘要)：最新的分子和遗传学研究 提示神经肽Y(NPY)介导的信号通路，即 在包括蠕虫和人类在内的动物中保守，参与调节 进食行为。然而，其监管机制尚不清楚。 这项提议的长期目标是了解果蝇的作用 神经肽F(NPF)是一种人类NPY同系物，在调节摄食行为中发挥作用。 潜在机制(S)，及其与脊椎动物的功能关系 神经肽Y家族分子。果蝇是唯一的无脊椎动物模型 神经肽Y及其受体的同源物已被鉴定的有机体。vbl.使用 整体原位RNA杂交和免疫细胞化学结果显示 DNPF在幼虫中枢神经系统和肠道中均有表达，幼虫中枢神经系统的dNPF能神经元 大脑支配食道下神经节、胸神经节和腹部神经节，因此 作为神经递质，调节大脑对摄食行为的控制。我们 还发现糖对味觉的刺激诱导了dNPF在两个 幼虫食道下神经节的附加神经元。表达式保持不变 长时间停糖后表现强劲，暗示dNPF参与碳水化合物的调节 苍蝇中枢神经系统的条件反射。食物摄取增强了dNPF中肠的表达， 并因饥饿而减少。其中一个可能的dNPF受体表达于 幼虫的肠道，大脑，可能还有唾液腺。因此，dNPF还可以作为 一种胃肠激素，协调各种不同的摄食相关活动 纸巾。在此应用程序中，我们建议直接测试 通过解决以下特定目标在转基因果蝇中进行dNPF：1) 用可控方法构建功能获得型转基因果蝇幼虫 异位表达dNPF并分析其取食行为；2)克隆和 利用UAStauGFP报告基因对dNPF顺式调控元件的表征 3)靶向构建功能丧失转基因幼虫 DNPF的功能敲除和确定大脑的特定角色， 食道下神经节和中肠dNPF在摄食行为中的作用这些研究 应提供对摄食的信号机制的一般见解 对无脊椎动物以及包括人类在内的高等动物的监管。

DESCRIPTION (applicant's abstract): Recent molecular and genetic studies indicate that a neuropeptide Y (NPY) mediated signaling pathway, which is conserved among animals including worms and humans, is involved in regulating feeding behavior. However, the mechanism for its regulation is not understood. The long term goal of this proposal is to understand the role of Drosophila neuropeptide F(NPF), a human NPY homolog, in modulating feeding behavior, the underlying mechanism(s), and its functional relationship to vertebrate neuropeptide Y family molecules. Drosophila is the only invertebrate model organism where homologs of NPY and its receptors have been identified. Using whole mount in situ RNA hybridization and immunocytochemistry, we showed that dNPF is expressed in both CNS and gut In larval CNS, dNPFergic neurons of the brain innervate subesophageal, thoracic, and abdominal ganglia, and may thereby act as neurotransmitters for mediating brain control of feeding behavior. We also found that gustatory stimulation by sugars induces dNPF expression in two additional neurons of larval subesophageal ganglion. The expression remains strong long after sugar withdrawl, implicating dNPF in mediating carbohydrate conditioning of fly CNS. The dNPF midgut expression is enhanced by food uptake, and reduced by starvation. One of the putative dNPF receptors is expressed in larval gut, brain and possibly salivary glands. Thus, dNPF may also function as a gut hormone that coordinates feeding associated activities in diverse tissues. In this application, we propose to directly test the specific roles of dNPF in transgenic flies by addressing the following specific aims: 1) Constructing gain-of-function transgenic Drosophila larvae through controlled ectopic dNPF expression and analyzing their feeding behaviors; 2) Cloning and characterization of cis regulatory elements of dNPF using UAStauGFP reporter system; 3) constructing loss-of-function transgenic larvae through targeted functional knockout of dNPF and determining the specific roles of brain, subesophageal ganglion and midgut dNPF in feeding behavior. These studies should provide general insights into the signaling mechanism for feeding regulation in invertebrates as well as higher animals including humans.