Embryonic Salivary Gland Development in Drosophila

描述：这项拟议的研究是申请者对 建立不同组织和器官的遗传机制 胚胎发生，包括定义器官的初始指令和 随后的细胞-细胞信号，基因表达的变化，以及细胞 建立分化器官并保持其特性的运动。学习 对果蝇胚胎唾液腺发育的研究导致了一种 唾液原基细胞的初步测定。唾液基因 表达被同源异型基因Sex Coms Reduced激活，而 涎腺和涎管原基的区别在于 表皮生长因子受体信号通路的相反活性及其机制 转录因子叉头。然而，无论是效应器还是 EGFR信号转导的靶点已经确定。在他们下定决心后不久， 唾液腺开始形成一种有序的内陷，始于唾液腺 胎盘的后背边缘，并继续到前缘，然后 胎盘的腹侧部分。这些管道是由位置符号的延续形成的 内陷以产生直径小得多的Y形管道 而不是腺体。尽管这种形态发生是高度有序的，但它的基因 对控制措施的调查才刚刚开始。有五个具体目标 这些实验：1)确定阻止fkh的Spitz依赖抑制物 在胆管前叶细胞中表达。2)定义无意义和 没有女儿。它们是否拮抗EGFR途径的影响；3)确定 Huckebein和无翼是否相互作用以启动和组织唾液 内陷；4)测试Tec29酪氨酸激酶是否调节细胞分裂 在唾液胎座中促进唾液形态发生；以及5)使用 敏化基因筛查确定唾液导管所需基因 发展。

DESCRIPTION: The proposed study is part of a broad interest by the applicant in the genetic mechanisms that establish distinct tissues and organs during embryogenesis, including both the initial instructions that define an organ and the subsequent cell-cell signaling, changes in gene expression, and cellular movements that build the differentiated organ and maintain its identity. Study of salivary gland development in Drosophila embryos has led to a model for the initial determination of cells in the salivary primordium. Salivary gene expression is activated by the homeotic gene Sex combs reduced, and the salivary gland and salivary duct primordia are distinguished from each other by the opposing activities of the EGF receptor signaling pathway and the transcription factor fork head. Nevertheless, neither the effectors nor the targets of EGFR signaling have been defined. Shortly after their determination, salivary glands begin to form by an orderly invagination that begins at the posterior dorsal edge of the placode and continues to the anterior and then ventral parts of the placode. The ducts form by a continuation of the placode invagination to produce the Y-shaped ducts that are much smaller in diameter than the glands. Although this morphogenesis is highly ordered, its genetic control is just beginning to be investigated. There are five Specific Aims for these experiments: 1) identify the spitz-dependent repressors that prevent fkh expression in the pre-duct cells. 2) define the roles of senseless and daughterless. Do they antagonize the effects of the EGFR pathway; 3) determine whether huckebein and wingless interact to initiate and organize salivary invagination; 4) test whether the Tec29 tyrosine kinase regulates cell division in the salivary placode to facilitate salivary morphogenesis; and 5) use a sensitized genetic screen to identify genes required for salivary duct development.