SOMA-TO-GERMLINE SIGNALING IN OOGENESIS IN DROSOPHILA

果蝇卵发生过程中的体细胞到种系信号传导

• 批准号: 2884105
• 负责人: STEPHEN M JACKSON
• 金额: $ 7.3万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-30 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2884105
• 关键词: Drosophilidae; biological signal transduction; cell type; cyclic AMP; cytoskeleton; developmental genetics; enzyme activity; oogenesis; phenotype; protein kinase A; protein kinase C; protein localization

The cut locus of D. melanogaster is an integral part of a communication pathway between two different cell types of the ovary. Loss of cut function in the somatic follicle cells interferes with these communications, disrupting the structural integrity of the germline-derived cells enclosed within the follicular epithelium We have shown by genetic analyses that mutations in cyclic-AMP dependent Protein kinase A (Pka-C1), agnostic, a gene that affects cAMP metabolism, and cappuccino and ovarian tumor, two genes that influence cytoskeletal function, interact genetically with cut mutations in this process. These results led us to hypothesize that cut activity in the follicle cells regulates a signaling pathway that impinges on the function of agnostic, cappuccino, and ovarian tumor in the germline cells. In this proposal, the function of these genes in this novel pathway is analyzed using a four-pronged approach. First, we will determine the mechanism responsible for the response of cappuccino and ovarian tumor to cut- and cAMP-mediated signaling by examining the expression, localization and phosphorylation state of these proteins when these pathways are disrupted. Second, we will determine the mechanism used by cut and agnostic in regulating cAMP levels and Pka-C activity in the germline by measuring cAMP levels, Pka-C catalytic activity, and agnostic expression levels when cut function is disrupted. Third, we will determine the importance of localized Protein kinase A activity in regulating the morphology of the germline cells by asking whether ectopic expression of PKA constructions or a dominant negative AKAP fragment can produce a multinucleate cell phenotype. Finally, we ask whether an A-kinase anchoring protein uncovered by a deficiency that interacts with cut mediates germ cell cytoskeletal integrity. Together, these experiments will determine how a communication pathway transmits a signal from one cell type through Protein kinase A to the cytoskeleton of another cell type.

黑腹果蝇的切割轨迹是卵巢两种不同细胞类型之间通讯途径的组成部分。体细胞中CUT功能的丧失干扰了这些通讯，破坏了卵泡上皮内生殖系来源细胞的结构完整性。我们通过遗传分析表明，在这一过程中，影响cAMP代谢的基因--环磷酸腺苷依赖性蛋白激酶A(PKA-C1)、不可知性基因以及卡布奇诺和卵巢肿瘤--这两个影响细胞骨架功能的基因--的突变与CUT突变存在遗传上的相互作用。这些结果使我们假设，卵泡细胞中的切割活性调节了一条信号通路，该通路影响生殖细胞中不可知性、卡布奇诺和卵巢肿瘤的功能。在这项建议中，这些基因在这一新途径中的功能是用四管齐下的方法分析的。首先，我们将通过检测当这些通路被破坏时这些蛋白的表达、定位和磷酸化状态来确定卡布奇诺和卵巢肿瘤对切割和cAMP介导的信号的反应的机制。其次，我们将通过测量cAMP水平、PKA-C催化活性以及当CuT功能中断时的不可知性表达水平来确定CuT和不可知性在调节胚系中cAMP水平和PKA-C活性方面的作用机制。第三，我们将通过询问PKA结构的异位表达或显性负的AKAP片段是否能产生多核细胞表型来确定定位的蛋白激酶A活性在调节生殖系细胞形态中的重要性。最后，我们询问A-激酶锚定蛋白是否通过与CUT相互作用的缺陷而被发现，从而调节生殖细胞细胞骨架的完整性。总而言之，这些实验将确定通讯途径如何通过蛋白激酶A将信号从一种细胞类型传递到另一种细胞类型的细胞骨架。