Regulation of Germ Cell Fate During Embryogenesis

胚胎发生过程中生殖细胞命运的调节

• 批准号: 7983744
• 负责人: GERALDINE Catherine Joelle SEYDOUX
• 金额: $ 27.22万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-18 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7983744
• 关键词: Anterior; Architecture; Automobile Driving; Binding; Biochemical; Biochemical Genetics; Biological Models; Caenorhabditis elegans; Cell Polarity; Cell division; Cells; Complement; Complex; Cues; Cytoplasm; Cytoplasmic Granules; Data; Development; Developmental Biology; Diffuse; Diffusion; Embryo; Embryonic Development; Epithelial Cells; Fluorescence; Genes; Genetic Techniques; Germ Cells; Goals; In Vitro; Lead; Life; Link; Lymphocyte; Microscopy; Mitosis; Modeling; Neurons; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphorylation Site; Phosphotransferases; Proteins; RNA-Binding Proteins; Regulation; Role; Somatic Cell; Specificity; Spectrum Analysis; System; Testing; Time; Transcription Repressor/Corepressor; cell type; design; human JTB protein; human RBM5 protein; in vivo; mutant; neuronal cell body; polarized cell; prevent; protein aggregate; protein complex; public health relevance; tumor; uncontrolled cell growth; zygote

DESCRIPTION (provided by applicant): The long-term goal of this project is to characterize the mechanisms that distinguish germ cells from somatic cells, a fundamental problem in developmental biology. In C. elegans, soma- germline asymmetries are established in the zygote before the first division, through the asymmetric partitioning of proteins and protein/RNA complexes in the cytoplasm. Cytoplasmic partitioning is regulated by conserved polarity regulators (PAR proteins), which localize asymmetrically in the zygote cortex. The goal of this proposal is to uncover how PAR activity at the cortex regulates polarity in the cytoplasm. Specific Aim I (SA1) will focus on the mechanisms that segregate the RNA-binding protein MEX-5 to the anterior cytoplasm. Preliminary data suggest that MEX-5 asymmetry depends on phosphorylation by PAR-1, a kinase on the posterior cortex, which increases MEX-5 diffusion locally in the posterior cytoplasm. SA2 will focus on the germline determinant PIE-1, which segregate to the posterior, opposite MEX-5 and in a steeper gradient. We will investigate how PIE-1 integrates both cortical and cytoplasmic cues to form a distinct gradient. Finally, SA3 will focus on the mechanisms that localize P granules to the posterior. P granules are evolutionarily conserved RNA-protein complexes specific to the germline. We have discovered a new P granule component PPTR-1 for P granule integrity during mitosis; our initial findings suggest that the germline specificity of P granules depends on regulated assembly and does not require cytoplasmic partitioning. We will use a combination of biochemical, genetic, and live microscopy approaches to test each of these hypotheses, and identify the genes and biochemical interactions involved. Unlike other well-studied embryonic polarity models, our system does not rely on pre-localized RNAs to generate asymmetry, and thus gives us the unique opportunity to explore the mechanisms that directly segregate proteins in the cytoplasm. PUBLIC HEALTH RELEVANCE: Cell polarity is essential to generate cell diversity during development, to prevent uncontrolled cell growth, and for the every-day functioning of many polarized cell types (epithelial cells, neurons, and lymphocytes). By taking advantage of a simple model system, our studies will illuminate the mechanisms that build and maintain the architecture of many cell types and prevent tumor formation.

描述（由申请人提供）：该项目的长期目标是表征区分生殖细胞和体细胞的机制，这是发育生物学中的一个基本问题。In C.在线虫中，索马-生殖系不对称性在第一次分裂之前通过蛋白质和蛋白质/RNA复合物在细胞质中的不对称分配在合子中建立。胞质分配是由保守的极性调节因子（PAR蛋白），它不对称地定位在受精卵皮层。这个提议的目的是揭示皮质PAR活性如何调节细胞质极性。特异性目标I（SA 1）将重点关注将RNA结合蛋白MEX-5分离到前细胞质的机制。初步数据表明，MEX-5的不对称性依赖于PAR-1的磷酸化，PAR-1是后皮质上的一种激酶，其增加了MEX-5在后细胞质中的局部扩散。SA 2将集中在生殖系决定子PIE-1上，其分离到后部，与MEX-5相对，并且以更陡的梯度分离。我们将研究PIE-1如何整合皮质和细胞质的线索，形成一个独特的梯度。最后，SA 3将集中在P颗粒定位到后方的机制。P颗粒是生殖细胞特异性的进化保守的RNA-蛋白质复合物。我们已经发现了一个新的P颗粒组件PPTR-1的P颗粒完整性在有丝分裂过程中，我们的初步研究结果表明，P颗粒的种系特异性依赖于调节组装，并不需要细胞质分区。我们将使用生物化学，遗传学和活体显微镜方法的组合来测试这些假设中的每一个，并确定所涉及的基因和生物化学相互作用。与其他研究充分的胚胎极性模型不同，我们的系统不依赖于预先定位的RNA来产生不对称性，因此为我们提供了探索直接分离细胞质中蛋白质的机制的独特机会。 公共卫生关系：细胞极性对于在发育期间产生细胞多样性、防止不受控制的细胞生长以及许多极化细胞类型（上皮细胞、神经元和淋巴细胞）的日常功能至关重要。通过利用一个简单的模型系统，我们的研究将阐明建立和维持许多细胞类型的结构并防止肿瘤形成的机制。