Cell Polarity and Cytoskeletal Transport in Drosophila

果蝇的细胞极性和细胞骨架运输

• 批准号: 6744150
• 负责人: Thomas S Hays
• 金额: $ 27.47万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6744150
• 关键词: Drosophilidae; cell differentiation; cellular polarity; cytoskeleton; dynein ATPase; gene mutation; green fluorescent proteins; immunoprecipitation; in situ hybridization; intracellular transport; ion exchange chromatography; kinesin; mass spectrometry; matrix assisted laser desorption ionization; microtubules; molecular cloning; myosins; oogenesis; phenotype; polymerase chain reaction; site directed mutagenesis

DESCRIPTION (provided by applicant): Cell polarity or asymmetry is fundamental to the development and morphogenesis of all organisms. Over the past two decades, the subcellular localization of RNAs that encode transcription and translational regulators of gene activity has emerged as a major mechanism underlying cellular asymmetries. Our molecular understanding of how the initial asymmetry plays out in terms of regulating gene activities and cell identities within an embryo has grown rapidly. By comparison, the cellular mechanisms that underlie the cytoplasmic transport and localization of mRNAs are not well understood. We are studying the asymmetric transport of mRNA determinants required for the specification and differentiation of the Drosophila oocyte. The Drosophila oocyte exhibits some of the best studied examples of the mRNA localization strategy. Most notably, the localization of Bicoid mRNA to the anterior and Oskar mRNA to the posterior of the oocyte is critical for establishing axial patterning in the embryo. Genetic analysis has described a pathway of gene products that act in a stepwise fashion to restrict the localization of Bicoid and Oskar mRNAs. This pathway most likely includes specific components that act in trans to regulate the recognition, transport, and targeting of specific RNAs. Other components of transport may not be specific to oogenesis and are yet to be identified. Our plan includes three specific aims. 1) We will characterize the in vivo motility of GFP-tagged components of the anterior/posterior (A/P) pathway. The motors responsible for transport will be determined using strategies to disrupt or eliminate motor function. 2) Biochemical studies will be pursued to investigate the composition of the RNP complexes in an effort to identify the molecular link(s) to motor proteins. 3) To characterize new gene products identified in a novel screen that exhibit microtubule-dependent accumulation in the oocyte. The function of two newly identified loci as potential components of the RNP transport machinery in oocyte development will be investigated.

描述（由申请人提供）：细胞极性或不对称性是所有生物体发育和形态发生的基础。在过去的二十年里，编码基因活性转录和翻译调节因子的RNA的亚细胞定位已成为细胞不对称的主要机制。我们对最初的不对称性如何在调节胚胎内的基因活动和细胞特性方面发挥作用的分子理解已经迅速发展。相比之下，mRNA 的细胞质运输和定位的细胞机制尚不清楚。我们正在研究果蝇卵母细胞的规范和分化所需的 mRNA 决定簇的不对称转运。果蝇卵母细胞展示了一些 mRNA 定位策略研究最深入的例子。最值得注意的是，Bicoid mRNA 定位于卵母细胞的前部，Oskar mRNA 定位于卵母细胞的后部，对于在胚胎中建立轴向模式至关重要。遗传分析描述了基因产物的途径，该途径以逐步的方式限制 Bicoid 和 Oskar mRNA 的定位。该途径很可能包括反式作用的特定成分，以调节特定 RNA 的识别、运输和靶向。运输的其他组成部分可能不是卵子发生所特有的，并且尚未确定。我们的计划包括三个具体目标。 1) 我们将描述前/后 (A/P) 通路 GFP 标记成分的体内运动特性。负责运输的电机将通过破坏或消除运动功能的策略来确定。 2) 将进行生化研究来研究 RNP 复合物的组成，以鉴定与运动蛋白的分子联系。 3) 表征在新型筛选中鉴定出的新基因产物，这些产物在卵母细胞中表现出微管依赖性积累。将研究两个新确定的基因座作为卵母细胞发育中 RNP 运输机制的潜在组成部分的功能。