ANALYSIS OF SENSORY NEURON DEVELOPMENT

我们正在研究控制分离的分子机制。 (分层) 果蝇中的神经元前体。为了搬出 神经前体细胞--神经直肠上皮细胞的活跃变化 它们的细胞骨架和与邻近细胞的接触。自那以后， 根据最近的发现，许多控制这些基因的基因 进程参与其他(非神经)的分层 组织也是如此，我们的研究与形态发生运动有关 总体而言。这些研究最终也具有临床重要性， 因为在正常情况下控制细胞运动的分子 发育(例如，钙粘附素；果蝇Notch和 无翼基因)在肿瘤生长中也起着核心作用。 这项建议的具体目标是分子分析 两个涉及神经元前体分离的基因，淡淡的香肠 (Fas)和猎枪(Shg)。Fas基因突变导致细胞骨架改变 在许多上皮细胞中，与极性的丧失和 这些细胞的单层排列。在神经胚层中，这些 改变会导致神经元前体分层的缺陷。在Shg中 突变胚胎，有广泛的神经直肠胚层退化 (以及其他特化的上皮细胞)。在前述授予中 期间，fas和shg均表现为表型和 从基因上来说。我们借助P1质粒交叉克隆了Fas FAS断点和FAS中的PlacZ插入。Shg基因的克隆 通过从P1质粒开始在粘粒文库中行走而启动的。在……里面 本应用实验是为了识别fas和shg。 并鉴定它们的序列和表达模式。 对于fas和shg，在大肠杆菌中表达的融合蛋白将是 用来产生抗体。分离自交系的种系转化 将尝试进行基因组克隆来挽救突变。我们会 筛选影响早期神经发生的其他突变。 前述批准期的工作已确定存在 分层和有丝分裂中细胞骨架变化的相似性， 而这两个突起在神经外胚层中的模式是 密切相关。我们已经证明了两个已知的基因可以控制 去膜、去翅和去翅对细胞有丝分裂的影响 神经直肠上皮细胞也是。我们在这里提出了一套发展性的- 基因实验解决了两者之间的关系 分层和有丝分裂及其神经源性和节段性调控 更详细地说，极性基因。

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.