MOLECULAR GENETICS OF DEVELOPMENT IN DICTYOSTELIUM

该项目的长期目标是分子技术的应用。 了解细胞机制和基因的遗传工具 差异化所必需的流程和 形态发生。目标是识别、分离和 描述对发育起关键作用的基因 盘状网柄线虫。这种真核阿米巴生物 为研究细胞功能提供了一个独特的模型系统 都参与了开发工作。在开发过程中，制服 阿米巴细胞群体分化为多细胞 由两种细胞类型组成的有机体，具有高度调控的 空间组织。运动性、信号转导、黏附、 形态发生信号与细胞类型特异性基因调控 是这种生物利用的基本过程之一 完成其发展规划。所获得的信息 关于这些功能是如何在Dictyostelius中完成的 为其他生物体的类似功能提供线索。 了解细胞的间接遗传学方法 将采取与发展相关的进程。变种人 对发展至关重要的进程的影响将是 然后，突变的基因将被分离出来。 通过这种方式，可以直接处理关键功能元素 收获了。影响发育的突变在 但分离突变基因的方法 从来都没有空闲时间。DNA介导的转化系统 将为突变和分离这些基因提供手段 基因。实现这一目标的两种方法是 并行进行的。反义RNA合成的反义RNA 转化载体将被用来抑制表达 必要的发育基因，或插入到 染色体将被用来中断基因表达。在这两个地方 病例中，将对大量转化子进行筛查 由转化载体引起的形态发生缺陷。 然后，载体序列将提供分离 失活基因。这个项目的目的不仅仅是为了 克隆更多的基因来研究它们的调控。相反，它是用来 分离重要基因的功能标准作为一种手段 最终研究基因产物的功能。

The long range goal of this project is the application of molecular genetic tools to understanding the cellular mechanisms and processes that are necessary for differentiation and morphogenesis. The objective is to identify, isolate and characterize genes that are essential for development of Dictoyostelium discoideum. This eucaryotic amoebal organism provides a unique model system for the study of cellular functions that are involved in development. During development, a uniform population of amoebal cells differentiates into a multicellular organism consisting of two cell types with a highly regulated spatial organization. Motility, signal transduction, adhesion, morphogenetic signalling and cell type specific gene regulation are among the fundamental processes utilized by this organism to accomplish its developmental program. The information gained about how these functions are accomplished in Dictyostelium will provide clues to similar functions in other organisms. An indirect genetic approach to understanding the cellular processes related to development will be taken. Mutants that affect processes that are essential for development will be identified, and then the genes that were mutated will be isolated. In this way, a direct handle on critical functional elements can be gained. Mutants that affect development are not new in Dictyostelium, but the means to isolate the mutated genes has never been available. The DNA mediated transformation system will provide the means for both mutating and isolating these genes. Two approaches to accomplishing this goal will be undertaken in parallel. Antisense RNA synthesized from a transformation vector will be used to inhibit expression of essential developmental genes, or a vector that inserts into the chromosome will be used to interrupt gene expression. In both cases, large numbers of transformants will be screened for defects in morphogenesis caused by the transformation vector. The vector sequence will then provide the means for isolating the inactivated gene. The purpose of this project is not simply to clone more genes to study their regulation. Rather it is to use functional criteria to isolate important genes as a means to eventually studying the function of the gene products.