Dynamics of signal transduction in the system of organogenesis and regeneration

我们利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，以澄清控制早期发育的机制，该机制包括复杂的细胞与细胞之间的相互作用，我们称之为早期发育系统，以及它们的分子成分之间的关系。我们还对分析确定的成分(基因和蛋白质)进行了功能分析，以询问它们在体内早期胚胎发育中的作用。通过Naoto Ueno、Masanori Taira和Kosuke Tashiro的协调，以非洲爪哇为模型系统，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，利用微阵列对发育早期的基因表达进行了综合分析，进行了基因表达的时空分析，并构建了包含这些信息的数据库。特别是，上野和Tashiro优化了高密度微阵列和多肽生长因子在胚胎中过度表达的组合方法。通过我们建立的分析，上野和泰拉分别专注于原肠形成和头部发育的调节，并研究了已发现的几个与这些发育事件有关的基因的功能。小林聪建立了一种通过在生殖细胞特异性启动子的调控下表达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一些与生殖细胞分化、维持和迁移有关的基因。值得注意的是，一大组基因被预测与一种特定的功能有关。综上所述，这些成果证明，对基因进行系统和全面的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.