Systems analysis of cell type differentiation in xenopus development

描述（由申请人提供）：我们提出了一个系统生物学框架的综合理解的早期脊椎动物胚胎发育的信号和转录事件，导致主要的外胚层，中胚层和内胚层细胞类型，使用非洲爪蟾模型系统。三个信号通路，Bmp，Nodal和Wnt的控制操作，将用于驱动多能胚胎细胞在不同的明确定义的发展方向。我们将描述每种终点细胞类型和许多中间体的特征，提供对细胞做出命运选择时蛋白质和mRNA水平变化的逐步分析。我们的团队是两个专家胚胎学家/细胞生物学家（Kirschner和Gerhart）与系统分析和统计推断专家（Peshkin）和蛋白质组质谱专家（Gygi）之间的密切合作。我们最近开发的方法将使我们能够达到前所未有的水平的检测和定量的蛋白质，蛋白质翻译后修饰，和mRNA转录。非洲爪蟾卵和胚胎的大尺寸也允许在某些情况下进行单细胞研究。 我们假设，高质量的蛋白质组分析的早期发展将产生新的关键见解发育信号通路。我们的数据集将提供前所未有的系统水平的知识，关于蛋白质在早期脊椎动物发育中的定位和时间依赖性作用，在注定成为不同细胞类型的细胞中。这些信息对于许多生物学问题来说是新的，对于胚胎学来说是革命性的。我们的一套方法将允许快速分析发育信号对关键通路的影响，以及对脊椎动物胚胎发育的影响。这些关键途径在以后的发育过程中也很重要，在儿童发育，成人的组织和细胞周转，以及基于干细胞生物学的再生医学方法中。它们在物种间也很大程度上是保守的，有望从模型系统快速转移到人类患者。我们希望这些数据将以新的方式为人类胚胎和儿童的遗传缺陷提供信息。

DESCRIPTION (provided by applicant): We propose to advance a systems biology framework for an integrative understanding of the signaling and transcriptional events in early vertebrate embryonic development leading to major ectodermal, mesodermal, and endodermal cell types, using the Xenopus laevis model system. Controlled manipulation of three signaling pathways, Bmp, Nodal, and Wnt, will be used to drive multipotent embryonic cells in different well-defined developmental directions. We will characterize each of the endpoint cell types and many intermediates, providing a step- by-step analysis of the changes in protein and mRNA levels as a cell makes fate choices. Our team is a close collaboration between two expert embryologists/cell biologists (Kirschner and Gerhart) with an expert in systematic analysis and statistical inference (Peshkin) and an expert in proteomic mass spectrometry (Gygi). Our recently developed methods will allow us to reach unprecedented levels of detection and quantification of proteins, protein post-translational modifications, and mRNA transcripts. The large size of Xenopus eggs and embryos will also permit single-cell studies in some cases. We hypothesize that high quality proteomic profiling of early development will produce new key insights into developmental signaling pathways. Our dataset will provide an unprecedented degree of systems-level knowledge on the localization- and time-dependent actions of proteins in early vertebrate development, in cells fated to become different cell types. This information will be new for many biological problems, and revolutionary for embryology. Our suite of methods will allow rapid profiling of the effect of developmental signals on key pathways, and on vertebrate embryonic development in general. These key pathways are also important in later developmental processes, in childhood development, tissue and cell turnover in adults, and in approaches to regenerative medicine based on stem cell biology. They are also largely conserved across species, promising rapid transfer from the model system to human patients. We expect that these data will inform on heritable defects in human embryos and children in new ways.