Mechanisms patterning the midface

项目摘要/摘要：本提案的长期目标是了解 面中部骨骼，在正常发育期间和人类遗传病条件下都是如此。脸部中部 由鼻子、眼睛和上颌周围的结构组成。人类遗传性疾病，比如 额鼻发育不良，影响这些面中部结构。具体来说，ALX转录因子编码基因 与多种类型的额鼻发育不良有关。独一无二的是，我们将这些疾病 斑马鱼通过使用基因突变。我们认为ALX基因的功能是指定一种身份代码，该代码 脊椎动物面部中部的图案。我们的模型借鉴了DLX和HOX代码等示例，它们指定了 在头面部骨骼的背腹轴和前后轴上分别具有同一性。我们建议 三个具体的目的是测试我们创新的“ALX-牛眼密码”假说，即嵌套的ALX基因表达 直接调节额鼻骨骼的特性。在目标1中，我们定义了源于 利用原位杂交、活细胞追踪和谱系追踪，野生型中的ALX-牛眼编码。目标2将 确定ALX基因组合是否起到指定额鼻特征的作用。为了识别这些功能， 我们将比较野生型和ALX突变体，检查基因表达、骨骼细胞分化和 错误表达的表型。目标3将揭示ALX基因是如何分子控制细胞特性的。我们会 检查体内Alx直接转录报告芯片序列以确定Alx蛋白在 基因组和Hi-C来揭示Alx介导的增强子-启动子的接触。这个提议的意义是很高的， 我们提出的在ALX牛眼密码中起作用的基因有直接的人类同源基因，这些基因与 面部中部畸形。这一提议是创新的，因为还没有一个模式化的代码 建议用于脊椎动物的中面。这项建议的成功将增进我们对面中部的理解 颅面发育与人类疾病。通过利用斑马鱼系统的优势来阐明 额鼻发育不良的分子、细胞和遗传机制，我们正在履行 NIDCR通过研究改善人类健康。

PROJECT SUMMARY/ABSTRACT: The long-term objective of this proposal is to understand formation of the midface skeleton, both during normal development, and in human genetic disease conditions. The midface consists of the structures around the nose, the eye, and the upper jaw. Human genetic disorders, like frontonasal dysplasia, affect these midface structures. Specifically, the ALX transcription factor encoding genes have been implicated in multiple types of frontonasal dysplasia. Uniquely, we model these diseases in zebrafish by using genetic mutants. We propose that the ALX genes function to specify an identity code which patterns the vertebrate midface. Our model draws from examples like the DLX and HOX codes, which specify identity in the dorsoventral and anteroposterior axes of the craniofacial skeleton, respectively. We propose three specific aims to test our innovative “alx-bullseye code” hypothesis, that nested alx gene expression directly regulates frontonasal skeletal identity. In Aim 1 we define the skeletal structures arising from the alx-bullseye code in wild types using in situ hybridization, live cell tracking, and lineage tracing. Aim 2 will determine whether alx gene combinations function to specify frontonasal identity. To identify these functions, we will compare wild types to alx mutants examining gene expression, skeletal cell differentiation, and misexpression phenotypes. Aim 3 will uncover how alx genes molecularly control cellular identity. We will examine an in vivo Alx direct transcriptional reporter, ChIP-seq to identify Alx protein occupancy across the genome, and Hi-C to reveal enhancer-promoter contacts mediated by Alx. Significance of this proposal is high, the genes that we propose function in the alx bullseye code have direct human orthologs that are associated with midface dysmorphologies. This proposal is innovative, as there has not yet been a patterning code proposed for the vertebrate midface. Success of this proposal will enhance our understanding of midface craniofacial development and human disease. By using the strengths of the zebrafish system to elucidate the molecular, cellular, and genetic mechanisms underlying frontonasal dysplasia, we are fulfilling the mission of the NIDCR to improve human health through research.