Dynamics of signal transduction in the system of organogenesis and regeneration

我们使用模型动物进行了一系列系统和全面的研究，以建立一个平台，阐明控制早期发育的机制，包括复杂的细胞间相互作用，我们称之为“早期发育系统”，以及它们的分子组成部分之间的关系。我们还对通过分析鉴定的组分（基因和蛋白质）进行了功能分析，以询问它们在早期胚胎发生中的体内作用。通过上野直人、平正典、田代康介的合作，以非洲爪蟾为模型系统，构建了cDNA文库，测定了cDNA的核苷酸序列，制作了高密度微阵列，通过微阵列对早期发育过程中的基因表达进行了综合分析，进行了时空基因表达分析，并构建了包含这些信息的数据库。特别是，Ueno和Tashiro优化了高密度微阵列和胚胎中多肽生长因子过表达的组合方法。通过我们建立的分析，Ueno和Taira分别专注于原肠胚形成和头部发育的调节，并研究了这些发育事件所必需的几个基因的功能。Satoru小林建立了通过在生殖细胞特异性启动子的调节下表达GFP来特异性标记生殖细胞的方法，并通过细胞分选来选择生殖细胞。生殖细胞特异性基因的微阵列分析确定了许多与生殖细胞分化、维持和迁移有关的基因。值得注意的是，鉴定了一大组被预测参与一种特定功能的基因。这些研究成果表明，系统而全面的基因分析对于阐明早期发育过程的分子网络是非常有效的。

We performed a series of investigations involving systematic and comprehensive studies using model animals, to establish a platform for clarifying the machinery that controls early development consisting of complex cell-to- cell interactions "Early developmental systems" which we call and the relationship among their molecular components. We also carried out functional analyses of components (genes and proteins) identified by the analyses to ask their in vivo role in early embryogenesis. By the coordination of Naoto Ueno, Masanori Taira, and Kosuke Tashiro for using Xenopus laevis as a model system, construction of cDNA libraries, determination of nucleotide sequence of the cDNAs, fabrication of high-density microarray, comprehensive analyses of gene expression by the microarray during early development, spatial and temporal gene expression analysis, and construction of databases containing those information were achieved. Particularly, Ueno and Tashiro optimized the combined methodology of the high-density microarray and overexpression of polypeptide growth factors in embryos. Through the analyses which we established, Ueno and Taira focused on the regulation of gastrulation and head development, respectively, and investigate the function of the identified several genes essential for those developmental events. Satoru Kobayashi established a method of labeling germ cells specifically by expressing GFP under the regulation of a germ cell-specific promoter and germ cells were selected by cell- sorting. The microarray analysis of germ cell specific genes identified a number of genes implicated in germ cell differentiation, maintenance, and migration. It is noteworthy that a large group of genes that are predicted to be involved in one particular function was identified. Taken together these achievements prove that systematic and comprehensive analyses of genes are very effective to clarify the molecular network of early developmental processes.