Nitric Oxide and Responses to Hypoxia in Drosophila

描述（由申请人提供）：一氧化氮作为血压调节剂的发现，于1995年获得诺贝尔奖，对其在人体健康中的作用展开了激烈的研究。认识到一氧化氮作用的多样性、复杂性和保守性，对模式生物的研究显得相关和必要。在我们对果蝇的研究中，一氧化氮诱导的行为和生理变化与适应低氧（缺氧）的保守作用一致。在寻找其在哺乳动物中功能的其他相似之处时，我们发现一氧化氮激活了果蝇的先天免疫反应。我们开发了强大的实验，标记转基因报告了幼虫或培养细胞（S2细胞）对一氧化氮、细菌或缺氧的免疫诱导。通过RNA干扰（RNAi）使特定基因失活，可以阻断S2细胞的应答。为了利用这一强大的基因解剖途径，我们构建了一个包含7200个rna的文库，这些rna代表了果蝇的保守基因。我们提出高通量RNAi筛选有助于免疫诱导的基因。在初步工作中，我们确定了参与对细菌成分反应的基因，并将对参与对一氧化氮和缺氧反应的基因进行同样的研究。我们将进一步利用我们的分析来定义基因作用的序列，从而描绘这些信号转导途径的区别和共同点。利用体内遗传学和培养试验，我们将把信号通路置于其生物学背景中。功能定位将基因作用置于级联反应中，将免疫反应从感染部位传递到远处组织。这些研究将为人类生理和健康的核心信号的作用提供新的模型。

DESCRIPTION (provided by applicant): The discovery of nitric oxide as a regulator of blood pressure, which was awarded the Nobel prize in 1995, launched intense investigation into its function in human health. Recognizing the diversity, complexity and conservation of nitric oxide actions, studies in model organisms appear relevant and needed. In our studies of Drosophila, nitric oxide induced behavioral and physiological changes consistent with a conserved role in adaptation to low oxygen (hypoxia). Seeking other parallels to its function in mammals, we found that nitric oxide activates innate immune responses in Drosophila. We developed robust assays in which tagged transgenes report immune induction in larvae or cultured cells (S2 cells) in response to nitric oxide, or to bacteria, or to hypoxia. The responses of S2 cells can be blocked by inactivation of specific genes by RNA interference (RNAi). To exploit this powerful avenue for genetic dissection, we constructed a library of 7,200 RNAs representing the conserved genes of Drosophila. We propose high-throughput RNAi screens for genes contributing to immune induction. In preliminary work, we identified the genes involved in the response to bacterial components and will do the same for genes involved in the responses to nitric oxide and hypoxia. We will further exploit our assays to define the sequence of gene action, thereby delineating distinctions and commonalities in the pathways transducing these signals. Using in vivo genetics and tests in culture, we will place the signaling pathways in their biological context. Localization of function will position gene action in a cascade that conveys immune responses from the site of infection to distant tissues. These studies will provide new models for the action of signals central to human physiology and health.