The Role of 5'Nucleotidase-expressing Cells in the Regulation of Morphogenesis in Dictyostellium

自20世纪30年代以来，发育生物学家研究了轴向梯度和极性建立的机制。 虽然早期的研究提供了有关形态发生的描述性信息，但他们也强调了分子方法的必要性。 目前有新的热情，技术和方法，现在可以定义这些分子事件。 关于目前的研究，几年前已经表明，在网骨藻细胞分化的时间过程中出现磷酸酶活性（5'NT），并且该活性变得限于形成两种分化细胞类型之间界面的窄带细胞。 该活性对5'AMP具有特异性，活性域从质膜的外表面延伸。 该项目有两个主要目标：（1）鉴定该基因通过破坏5'NT基因的表达、过表达和异位表达在调节形态发生中所起的作用。 通过分析细胞类型特异性标记物和指示两种主要细胞类型中分化进程的基因，和（2）鉴定导致5'NT基因细胞特异性表达的调节机制，来确定对形态发生的影响。 这将需要鉴定调节时间和空间表达的顺式作用因子，以及鉴定和克隆调节基因表达的反式作用因子。

Since the 1930's, developmental biologists have studied the mechanisms of axial gradients and the establishment of polarity. Although the early investigations offered descriptive information about morphogenesis they also emphasized the need for molecular approaches. There is currently renewed enthusiasm that the techniques and approaches are now available to define these molecular events. With regard to the present research, it was shown several years ago that a phosphatase activity (5'NT ) appeared during the time course of cell differentiation in Dictyostelium and that the activity becomes restricted to a narrow band of cells that form the interface between the two differentiating cell types. The activity was specific for 5'AMP and the activity domain extended from the external face of the plasma membrane. There are two major goals of the project: (1) to identify the role played by this gene in the regulation of morphogenesis by disruption of expression of the 5'NT gene, overexpression and ectopic expression. The resulting effects on morphogenesis will be determined through the analysis of cell-type specific markers and genes that are indicative of the progression of differentiation in the two major cell types, and (2) to identify the regulatory mechanisms that result in cell-specific expression of the 5'NT gene. This will require identification of cis-acting factors that regulate the temporal and spatial expression, and identification and cloning of trans-acting factors that regulate expression of the gene.