Nitric Oxide and Responses to Hypoxia in Drosophila

描述(申请人提供)：1995年获得诺贝尔奖的一氧化氮作为血压调节剂的发现，引发了对其在人类健康中作用的深入研究。认识到一氧化氮作用的多样性、复杂性和保守性，在模型生物体中进行研究似乎是相关和必要的。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(低氧)的保守作用一致。在哺乳动物中寻找其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。我们开发了可靠的分析方法，其中标记的转基因报告了幼虫或培养细胞(S2细胞)对一氧化氮、细菌或低氧的免疫诱导。通过RNA干扰(RNAi)使特定基因失活，可阻断S2细胞的反应。为了利用这一强大的遗传解剖途径，我们构建了一个包含7200个代表果蝇保守基因的RNA的文库。我们建议高通量的RNAi筛选有助于免疫诱导的基因。在前期工作中，我们确定了参与细菌成分反应的基因，并将对参与一氧化氮和低氧反应的基因进行同样的识别。我们将进一步利用我们的分析来定义基因作用的序列，从而描绘出转导这些信号的途径中的区别和共性。利用体内遗传学和培养测试，我们将把信号通路放在它们的生物学背景下。功能的定位将基因的作用定位在一个级联中，将免疫反应从感染部位传递到远处的组织。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.