Genetic Hierarchies and Cellular Behaviors during Zebrafish Palatogenesis

人类有数百种头面部疾病，其中以腭裂最为常见。的目标是 这一建议是为了阐明腭裂发生的信号相互作用和细胞行为。这个 斑马鱼为研究腭部发育提供了一个有用的模型系统。强大的基因和 细胞技术可用于研究斑马鱼的基因功能以及细胞和组织 信号相互作用。此外，简化的腭部骨骼，由更少的神经脊腭部组成 而斑马鱼胚胎的光学清晰度使其成为分析细胞的理想工具。 发生在腭部发育过程中的行为。我建议检验互惠信号假说的预测， 其中信号从神经脊到口腔外胚层，然后从口腔外胚层回到神经脊 诱导腭裂形成，并通过细胞插入导致腭部伸长。在特定的目标1，1 研究神经脊导出信号和口腔外胚层反应基因的候选基因的作用， 在口腔外胚层中打开。我使用功能丧失、基因表达、成像和遗传马赛克 FgflO和Bmp4信号在口腔中启动Pitx2模型的验证分析 外胚层，这反过来又促进了腭裂的发生。在特定目标2中，1从口头上分析互易信号 外胚层到神经脊。我使用功能丧失、成像和遗传马赛克分析以及 构建可诱导的转基因斑马鱼品系以验证PDGF和Eph/eaffin信号转导的预测 来自口腔外胚层促进了腭裂的发生。在特定的目标3，1中确定驱动细胞行为 上颌骨的伸长。我使用共聚焦时间推移分析以及小说的克隆和表征 斑马鱼上颚突变体测试细胞嵌入驱动斑马鱼伸展的预测 味觉。我在这些研究过程中获得的结果将有助于阐明基因和细胞 导致腭裂的原因。此外，我建议分析的两个基因，即Pitx2和ePhrin-B1，是已知的 人类头面部疾病基因。因此，我对这些基因的分析将提供对 人类疾病的起因。

There are hundreds of craniofacial diseases in humans and cleft palate is common among these. The goal of this proposal is to elucidate the signaling interactions and cellular behaviors underlying palatogenesis. The zebrafish provides a useful model system in which to study palatal development. Powerful genetic and cellular techniques are available in the zebrafish for studying gene function as well as cell and tissue signaling interactions. Additionally, the simplified palatal skeleton, consisting of far fewer neural crest palate progenitors than in mammals, and the optic clarity of the zebrafish embryo makes it ideal for analyzing cell behaviors occurring in palatogenesis. I propose to examine predictions of a reciprocal signaling hypothesis, in which signals from neural crest to the oral ectoderm and then back from the oral ectoderm to neural crest induce palatogenesis, and cause elongation of the palate through cell intercalations. In Specific Aim 1,1 examine the role of candidate genes for neural crest-derived signals and oral ectoderm response genes, turned on in the oral ectoderm. I use loss-of-function, gene expression, imaging, and genetic mosaic analyses to test the model that FgflO and Bmp4 signaling from the neural crest turns on pitx2 in the oral ectoderm, which, in turn, promotes palatogenesis. In Specific Aim 2,1 analyze the reciprocal signal, from oral ectoderm to neural crest. I use loss-of-function, imaging, and genetic mosaic analyses as well as construction of inducible transgenic zebrafish lines to test the prediction that Pdgf and Eph/ephrin signaling from the oral ectoderm promotes palatogenesis. In Specific Aim 3,1 determine the cell behaviors that drive elongation of the palate. I use confocal time lapse analysis as well as cloning and characterization of novel zebrafish palate mutants to test the prediction that cell intercalations drive the extension of the zebrafish palate. The results I obtain during the course of these studies will shed light on the genetic and cellular causes of cleft palate. Additionally, two genes I propose to analyze, pitx2 and ephrin-B1, are known to be human craniofacial disease genes. Therefore, my analyses of these genes will provide direct insight into the cause of human disease.