Systematic analysis of cell death regulation in mosquitoes

标题：蚊子细胞死亡调控的系统分析。 细胞死亡（凋亡）是载体/宿主免疫应答的重要组成部分 机制它与多种病原体的感染性生命周期有关，例如： 疟疾寄生虫和西尼罗河病毒。然而，我们对细胞死亡的理解 由于缺乏一份完整的主要昆虫清单， 细胞死亡调节剂，即 *Reaper/Hid/Grim样IAP拮抗剂，在注释的蚊子中 基因组 IAPs（细胞凋亡蛋白抑制剂）是核心细胞死亡机制的重要制动器 在昆虫中。它们与半胱天冬酶结合并抑制这些致命酶的活性。遗传研究 在果蝇中已经显示，在发育过程中大多数程序性细胞死亡是通过 IAP拮抗剂如Reaper、HID和Grim（RHG）在注定死亡的细胞中的特异性表达。 这些IAP拮抗剂中的大多数也是介导细胞死亡所必需的，以响应环境条件。 应力主要疟疾媒介冈比亚按蚊的基因组计划显示， 与果蝇相比，IAP和caspase基因家族显著扩增。这是 假设反映了响应微调细胞死亡调节的功能要求 寄生虫和病毒感染。这也强烈暗示IAP拮抗剂？？IAP？？Caspases 在果蝇中，细胞死亡信号通路对于蚊子的细胞死亡调节至关重要。 然而，由于广泛的序列分歧，注释的完整An.冈比亚基因组 序列最初不包括RHG样IAP拮抗剂的任何直系同源物。使用系统 通过生物信息学方法，我们鉴定并随后表征了第一个RHG样IAP拮抗剂， michelob_x（mx），存在于按蚊和伊蚊基因组中。为了调查这些 促凋亡基因介导的载体-病原体相互作用，我们确定了在库蚊mx直系同源物 发现库尼核型多角体病毒（CuniNPV）感染奎氏库尼氏蚊（Cx.quinauifasciatus）可诱导其发生 （第4.5节; Zhou et al，in preparation）。此外，我们还鉴定了另一种IAP拮抗剂， IBMP 6是果蝇Hid.有趣的是，ibmp 6是由MIV感染诱导的。 Aag 2细胞（第4.6节）。这些数据表明，与果蝇一样， 蚊子细胞死亡调节所需的。此外，使用不同的IAP拮抗剂 针对不同的感染或不同的组织。 由于IAP拮抗基因在昆虫细胞死亡调控中起着关键作用， 揭示了它们参与病原体诱导的载体反应，充分阐明了这组 蚊子中的基因对于全面了解细胞死亡调控至关重要， 对病原体攻击的反应以及在正常的蚊子生命周期中。本拟议项目 目的是（1）系统鉴定和功能验证IAP-拮抗剂在主要 蚊子基因组（2）阐明这些IAP拮抗剂在介导媒介-病原体相互作用中的作用 使用CuniNPV，MIV和B. algerae的相互作用。(3)开发公共资源， 分析蚊子的细胞死亡调节。 细胞死亡（凋亡）与多种病原体的感染生命周期有关，例如疟疾 寄生虫和西尼罗河病毒。了解细胞死亡反应将有助于我们开发 控制蚊子传播疾病和控制蚊子数量的策略。

Title: Systematic analysis of cell death regulation in mosquitoes. Cell death (apoptosis) is an important component of the vector/host immuno-response mechanism. It has been implicated in the infectious life cycle of a variety of pathogens, such as the malaria parasite and the West Nile virus, in mosquitoes. However, our understanding of cell death regulation in mosquitoes has been hindered greatly by the lacking of a complete list of major insect cell death regulators, i.e. the *Reaper/Hid/Grim -like IAP-antagonists, in the annotated mosquito genomes. IAPs (Inhibitor of Apoptosis Proteins) are the essential ¿Brake¿ of the core cell death machinery in insects. They bind to caspases and inhibit the activity of these ¿deadly¿ enzymes. Genetic studies in Drosophila have shown that most programmed cell death during development is mediated through specific expression of IAP-antagonists such as reaper, hid, and grim (RHG) in cells destined to die. Most of these IAP-antagonists are also required for mediating cell death in response to environmental stress. The genome project for the primary malaria vector, Anopheles gambiae, revealed a significant expansion of the IAP and caspase gene families when compared to Drosophila. This was postulated to reflect the functional requirement of fine-tuning cell death regulation in response to parasite and virus infection. It also strongly implies that the IAP-antagonist ?? IAP ?? Caspases pathway, as is in Drosophila, is fundamentally important for cell death regulation in mosquitoes. However, due to extensive sequence divergence, the annotated complete An. gambiae genome sequence did not initially include any ortholog of RHG-like IAP-antagonist. Using a systematic bioinformatics approach, we identified and subsequently characterized the first RHG-like IAPantagonists, michelob_x (mx), in Anopheles and Aedes genomes. To probe the involvement of these pro-apoptotic genes in mediating vector-pathogen interaction, we identified the mx ortholog in Culex and found that it is induced by CuniNPV (a mosquito baculovirus) infection to Cx.quinauifasciatus (section 4.5; Zhou et al, in preparation). In addition, we have identified another IAP-antagonist, IBMP6, as the ortholog of Drosophila Hid. Interestingly, ibmp6 is induced by MIV infection of the Aag2 cells (section 4.6). These data indicate that like in Drosophila, multiple IAP-antagonist are required for cell death regulation in mosquito. Further more, distinct IAP-antagonists is(are) utilized against different infections or in different tissues. Since the IAP-antagonist genes play pivotal roles in insect cell death regulation and our work revealed that they are involved in pathogen-induced vector response, elucidating fully this group of genes in mosquitoes will be essential for the comprehensive understanding of cell death regulation in response to pathogen challenge as well as during normal mosquito life cycle. This proposed project aims at (1) Systematic identification and functional verification of the IAP-antagonists in major mosquito genomes. (2)Elucidating the role of these IAP-antagonists in mediating vector-pathogen interaction using CuniNPV, MIV, and B.algerae. (3) Developing public resources for systematic analysis of cell death regulation in mosquitoes. Cell death (apoptosis) is implicated in the infectious life cycle of a variety of pathogens, such as the malaria parasite and the West Nile virus, in mosquitoes. Understanding cell death response will help us to develop strategy for controlling mosquito transmitted disease and for controlling mosquito population.