Oocyte development in Drosophila

描述(申请人提供)：这个项目的长期目标是以果蝇卵子发生为模型系统来阐明配子发育的机制，以及可用于果蝇遗传和细胞生物学方法的强大工具。一个重大的健康问题是暴露在环境压力下的生殖系细胞在成年人中的存活，例如营养不良和接触激进的药物。该项目开展的研究将影响对未成熟配子保护机制的理解，以确保它们在恶劣条件下存活。这个项目还将研究配子发育的一个基本和保守的方面--动物配子发生的一些或全部发生在合胞体细胞簇中，这些细胞通过被称为环管的细胞间桥相连。通过种系环管调节细胞质的胞间运动的机制将被检验以响应养分的可利用性。体细胞毛囊细胞之间也存在环状通道。 果蝇卵室，尽管它们的功能尚不清楚。这个项目将研究细胞质成分在体细胞环管中的运动，并使用新的方法来破坏体细胞环管以确定它们的功能。这一信息将影响对细胞间通过小环管的运动的理解，类似于连接发育中的精母细胞的环管。此外，这项研究中开发的工具将有助于研究其他果蝇组织中的体细胞环管。目的1通过控制果蝇胰岛素/类胰岛素(IIS)/Tor途径的成分，利用遗传学方法来确定卵母细胞发育过程中饥饿反应的机制。卵黄形成前卵室对营养不良作出反应，包括P小体增大和微管重组。IIS/Tor途径的多个成分将单独或组合在生殖系或卵泡细胞组织中表达或被破坏，以表征饥饿卵室中的后果。新的方法将允许跟踪饥饿的卵室，以详细检查它们的恢复情况，并将使用影响P小体组装的突变来确定削弱饥饿反应的后果。Aim 2将使用新的细胞标记技术和荧光蛋白来阐明卵室周围毛囊细胞上皮中环形通道的功能。实验将确定环状通道是否用于平衡转录上未协调的细胞之间的蛋白质水平。定向破坏体细胞环管的新方法将允许对破坏的合胞体进行表型分析，这些合胞体一直难以捉摸。这些研究将更好地确定卵泡细胞合胞体在卵室发育中所起的重要作用，这些新方法也可以应用于其他参与果蝇发育的体细胞合胞体。

DESCRIPTION (provided by applicant): The long-term goal of this project is to elucidate mechanisms of gamete development using Drosophila oogenesis as a model system, and the powerful tools available for genetic and cell biological approaches in Drosophila. A significant health concern is the survival of germline cells in adults exposed to environmental stresses such as poor nutrition and exposure to aggressive pharmaceuticals. Research carried out in this project will impact understanding of protective mechanisms used by immature gametes to ensure their survival through harsh conditions. This project will also investigate a fundamental and conserved aspect of gamete development - some or all of animal gametogenesis occurs in syncytial clusters of cells connected by intercellular bridges called ring canals. Mechanisms modulating intercellular movement of cytoplasm through germline ring canals in response to nutrient availability will be examined. Ring canals are also present between somatic follicle cells of the Drosophila egg chamber, although their function is not known. This project will investigate movement of cytoplasmic components through somatic ring canals, and use novel approaches for disrupting somatic ring canals to determine their function. This information will impact understanding of intercellular movement through small ring canals similar to those connecting developing spermatocytes. In addition, tools developed in this research will be useful for examining somatic ring canals in other Drosophila tissues. Aim 1 will use genetic approaches to determine the mechanism of the starvation response in oocyte development, by manipulating components of the Drosophila Insulin/insulin-like (IIS)/Tor pathway. Previtellogenic egg chambers mount a response to poor nutrition that includes enlarged P bodies and reorganization of the microtubules. Multiple components of the IIS/Tor pathway will be expressed or knocked down, individually or in combinations, in either the germline or the follicle cell tissues to characterize the consequences in starved egg chambers. New approaches will allow tracking of egg chambers that have been starved to examine their recovery in detail, and mutants affecting P body assembly will be used determine the consequences of crippling the starvation response. Aim 2 will use new cell marking techniques and fluorescent proteins to illuminate the function of ring canals in the follicle cell epithelium that surrounds the egg chamber. Experiments will determine whether ring canals serve to equilibrate protein levels between transcriptionally uncoordinated cells. New methods for targeted disruption of somatic ring canals will allow phenotypic analysis of disrupted syncytia, which have been elusive. The importance of the role that follicle cell syncytia play during egg chamber development will be better defined following these studies, and these new methods can then be applied to other somatic syncytia involved in development in Drosophila.