ANALYSIS OF SENSORY NEURON DEVELOPMENT

我们正在研究控制分离的分子机制 （脱层） 果蝇的神经元前体。为了走出困境， 神经外胚层上皮、神经元前体细胞发生活跃变化 它们的细胞骨架和与邻近细胞的联系。自从， 根据最近的发现，许多控制这些基因的基因， 参与其他（非神经） 我们的研究与形态发生运动有关， 梗概.这些研究最终也具有临床重要性， 因为正常情况下控制细胞运动的分子 开发（例如，钙粘蛋白;果蝇Notch的同源物， 无翅基因）也在肿瘤生长中起重要作用。 该提案的具体目标是对以下物质进行分子分析： 两个基因参与神经元前体分离，微弱的香肠 (fas)Shotgun（shg）fas突变引起细胞骨架改变 在许多上皮细胞中，与极性丧失有关， 这些细胞的单层排列。在神经外胚层中， 变化导致神经元前体分层中的缺陷。瘤shg 突变的胚胎，有一个广泛的神经外胚层退化 (as其他特化上皮细胞的孔）。在上述授予 期间，fas和shg均表现出表型特征， 遗传的我们用P1质粒杂交的方法克隆了Fas fas断点和fas中的PlacZ插入。shg基因的克隆是 通过在来自P1质粒的粘粒文库中开始步移来启动。在 本应用实验拟对fas和shg进行识别 转录本并表征其序列和表达模式。 fas和shg的融合蛋白在大肠杆菌中表达。大肠杆菌将是 用于产生抗体。我们分离的 将尝试基因组克隆以拯救突变。我们将 筛选影响早期神经发生的其他突变。 在前一批赠款期间的工作表明， 脱层和有丝分裂中细胞骨架变化的相似性， 这两个过程在神经外胚层中的模式 密切相关。我们已经证明了两个已知的控制基因 层离、Notch和无翅对有丝分裂有影响， 神经外胚层细胞也一样。我们在这里提出一套发展- 基因实验研究了 分层和有丝分裂，以及它们受神经原性和节段性 极性基因，更详细地说

We are studying the molecular mechanisms controlling the segregation (delamination) of neuronal precursors in Drosophila. In order to move out of the neurectodermal epithelium, neuronal precursors undergo active changes of their cytoskeleton and contacts to neighboring cells. Since, according to recent findings, many of the genes controlling these processes are involved in the delamination of other (non-neural) tissues as well, our studies have a bearing on morphogenetic movements in general. These studies ultimately are also of clinical importance, because the molecules controlling cell movements during normal development (e.g., cadherins; homologs of Drosophila Notch and wingless genes) also play a central role in neoplastic growth. The specific objectives of this proposal are the molecular analysis of two genes involved in neuronal precursor segregation, faint sausage (fas) and shotgun (shg). Mutations in fas cause cytoskeletal changes in many epithelial cells, associated with the loss of polarity and monolayered arrangement of these cells. In the neurectoderm, these changes lead to defects in neuronal precursor delamination. In shg mutant embryos, there is a widespread degeneration of the neurectoderm (as well of other specialized epithelia). In the foregoing granting period, both fas and shg were characterized phenotypically and genetically. We have cloned fas with the help of a P1 plasmid crossing the fas breakpoint and a PlacZ insertion in fas. Cloning of shg was initiated by starting a walk in a cosmid library from a P1 plasmid. In this application experiments are proposed to identify the fas and shg transcripts and characterize their sequence and expression pattern. For both fas and shg, fusion proteins expressed in E. coli will be used to generate antibodies. Germline transformation of our isolated genomic clones will be attempted to rescue the mutations. We will screen for additional mutations affecting early neurogenesis. Work of the foregoing granting period had established that there exist similarities between cytoskeletal changes in delamination and mitosis, and that the pattern of these two processes in the neurectoderm are closely correlated. We have shown that two genes known to control elamination, Notch and wingless, have an effect on mitosis of neurectodermal cells as well. We here propose a set of developmental- genetic experiments which address the relationship between delamination and mitosis, and their control by neurogenic and segment polarity genes, in greater detail.