The function of alpha-spectrin in the Drosophila nervous system

α-血影蛋白在果蝇神经系统中的功能

• 批准号: 5331982
• 负责人: Professor Dr. Christian Klämbt
• 金额: --
• 依托单位: Institut für Neuro- und Verhaltensbiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2001
• 资助国家: 德国
• 起止时间: 2000-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5331982?language=en
• 关键词: function; alpha; spectrin; Drosophila; nervous

Within the developing nervous system cell polarity is mostly evident in neuronal cells which form dendrites and axons with strictly separate membrane domains. We are interested in the role of cell polarity for the developing glial cells. In the Drosophila CNS the midline glial cells show a pronounced initial apico-basal polarity. During later developmental stages, the glial cells form basal cell processes that migrate towards commissural axons and concomitantly retract their apical cell processes. This polar cell organization is disturbed in klötzchen mutants that we have previously identified in a phenotypic screen. Klötzchen fails to complement alpha-spectrin and the mutant klötzchen phenotype can be rescued by expression of aspectrin using the ubiquitin promoter. Furthermore, klötzchen mutant cell clones lack alpha-spectrin expression. However, the alpha-spectrin null phenotype differs from the phenotype of the 8 independent klötzchen alleles that we have identified. In addition, the Drosophila alpha-spectrin gene is unusual as it encodes a second gene within its first intron that shares the first noncoding exon with the alpha-spectrin transcript. In the next two years we propose to molecularly identify the klötzchen mutation in either the alpha-spectrin gene or the intron-based gene. We want to address the question how the loss of alpha-spectrin leads to a disruption of the polar glial cells phenotype. Using other mutations affecting cell polarity we will determine whether glial cell polarity is required for later differentiation / function. In addition to further detailed phenotypic analyses, we will perform structure function studies of a-spectrin as well as we will perform genetic screens aimed to identify genes interacting with klötzchen. Our experiments will contribute to the understanding how alpha-spectrin regulates cell polarity and how this polarity is required for subsequent glial cell function.

在发育中的神经系统中，细胞极性在神经元细胞中最为明显，神经元细胞形成具有严格分离的膜域的树突和轴突。我们对细胞极性对于发育中的神经胶质细胞的作用感兴趣。在果蝇中枢神经系统中，中线神经胶质细胞显示出明显的初始顶端-基底极性。在后期发育阶段，神经胶质细胞形成基底细胞突起，向连合轴突迁移并同时缩回其顶端细胞突起。这种极性细胞组织在我们之前在表型筛选中鉴定出的 klötzchen 突变体中受到干扰。 Klötzchen 无法补充 α-血影蛋白，突变的 klötzchen 表型可以通过使用泛素启动子表达方面蛋白来挽救。此外，klötzchen 突变细胞克隆缺乏 α-血影蛋白表达。然而，α-血影蛋白无效表型与我们已鉴定的 8 个独立 klötzchen 等位基因的表型不同。此外，果蝇α-血影蛋白基因很不寻常，因为它在其第一个内含子内编码第二个基因，该内含子与α-血影蛋白转录物共享第一个非编码外显子。在接下来的两年中，我们建议从分子水平上鉴定α-血影蛋白基因或基于内含子的基因中的klötzchen突变。我们想要解决α-血影蛋白的缺失如何导致极胶质细胞表型破坏的问题。使用影响细胞极性的其他突变，我们将确定胶质细胞极性是否是以后分化/功能所必需的。除了进一步详细的表型分析之外，我们还将进行 a-血影蛋白的结构功能研究，并将进行旨在识别与 klötzchen 相互作用的基因的遗传筛选。我们的实验将有助于理解α-血影蛋白如何调节细胞极性以及后续神经胶质细胞功能如何需要这种极性。