Genetic Hierarchies and Cellular Behaviors during Zebrafish Palatogenesis

人类有数百种颅面疾病，腭裂是其中常见的。的目标 本研究旨在阐明腭发育过程中的信号转导和细胞行为。的 斑马鱼为研究腭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 信号交互此外，简化的腭骨骼，包括少得多的神经嵴腭 斑马鱼胚胎的光学清晰度使其成为分析细胞的理想工具， 发生在腭发育中的行为。我建议检查一个相互信号假说的预测， 其中信号从神经嵴到口腔外胚层，然后从口腔外胚层返回到神经嵴 诱导腭发生，并通过细胞插入引起腭的伸长。具体目标1.1 检查神经嵴衍生信号和口腔外胚层反应基因的候选基因的作用， 在口腔外胚层开启我用功能丧失基因表达成像和基因嵌合体 分析以测试来自神经嵴的FgflO和Bmp 4信号传导在口腔中开启pitx 2的模型。 外胚层，这反过来又促进了腭发育。在具体目标2中，我分析了互惠信号，从口头 外胚层到神经嵴我使用功能丧失成像和遗传镶嵌分析以及 构建可诱导的转基因斑马鱼系，以测试Pdgf和Eph/ephrin信号转导 促进腭发育。在具体目标3中，1确定细胞行为， 腭的伸长。我使用共聚焦时间推移分析以及克隆和表征的新的 斑马鱼腭突变体，以测试细胞插入驱动斑马鱼延伸的预测 上颚我在这些研究过程中获得的结果将阐明遗传和细胞 造成腭裂的原因此外，我建议分析的两个基因，pitx 2和ephrin-B1，已知是 人类颅面疾病基因。因此，我对这些基因的分析将为我们提供直接的见解， 人类疾病的原因。

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.