Decoding regulatory nodes controlling growth and proportion of the skull

解码控制头骨生长和比例的调节节点

基本信息

批准号：
10348718
负责人：
Katherine Christine Woronowicz
金额：
$ 7.25万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-01 至 2023-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10348718
关键词：
Address Adult Affect Anterior Articulation Base Pairing Binding Brain Branchial arch structure CRISPR/Cas technology Cartilage Cell Differentiation process Cephalic Cleft Palate Clinical Code Complex Congenital Abnormality Craniofacial Abnormalities Data Development Disease Elements Embryo Enhancers Essential Genes Event Evolution Face Fertilization First Pharyngeal Arch Fishes Fluorescent in Situ Hybridization Gene Expression Gene Expression Regulation Genes Genetic Enhancer Element Genomic approach Genotype Growth Head Homeobox Homeobox Genes Hour Human Human Development Introns Jaw Knowledge Light Limb Bud Link Mastication Mediating Midbrain structure Modification Morphogenesis Morphology Mus Mutation Neural Crest Neural Crest Cell Neural Fold Nucleic Acid Regulatory Sequences Oral cavity Oropharyngeal Outcome Measure Pan Genus Pattern Phenotype Play Primates Prognathism Regulation Regulatory Element Reporter Research Rest Role Sense Organs Signal Transduction Site Syndrome Synteny Testing Tissues Untranslated RNA Variant Vertebrates Work Zebrafish base bone cell motility comparative genomics craniofacial craniofacial complex craniofacial development craniofacial microsomia craniofacial structure cranium experimental study gene regulatory network hindbrain improved in vivo loss of function mutant neurodevelopment novel preservation pressure single molecule spatiotemporal trait

项目摘要

PROJECT SUMMARY The skull is comprised of bones of different embryonic origins that articulate to encase the brain, to protect the sense organs, and to enable mastication. Well-orchestrated signaling and morphological events generate the seamless morphology of the craniofacial complex. Of central importance are the cranial neural crest cells (CNCCs) that migrate from the anterior neural folds to populate the oropharyngeal arches. CNCCs acquire axial identity from midbrain and hindbrain segmentation. Modifications to gene expression of CNCCs, their precursors, their derivatives, or even interacting tissues may underlie both normal variation and common craniofacial malformations. Although the gene regulatory networks that govern early specification of CNCCs are well known, we still lack detailed knowledge of later developmental events involving CNCC derivatives and how this relates to fundamental mechanisms of disease. The experiments outlined in this proposal will tease apart the morphological consequences of genotype. We expect that loci modifying the relative proportions of the skull and face will have commonalities amongst jawed vertebrates, as the head is an ancestral trait. Our prior phylogenomic comparisons identified fixed loci correlated with differential developmental prognathism. One of the regions identified encompasses a locus containing a large, cis-regulatory region highly conserved in all jawed vertebrates. This locus rests in an intron of agap1, and has retained directional synteny with the nearest neighbor, homeobox gene gbx2, over all of vertebrate evolution. This 343 base pair (bp) region is defined as having over 90% identity among vertebrates. A core of over 190bp is retained with 100% identity among primates, suggesting deep conservation preserved by strong selective pressure and a potential role in human development. Preliminary analyses suggest the region may participate in a broader regulatory hub that modulates expression of gbx2. As gbx2 is essential for patterning CNCCs, and is expressed in the oropharyngeal arches, my hypothesis is that the conserved non-coding region we identified acts as a specific enhancer for gbx2, mediating patterning of the forming arches and leading to proportional changes in outgrowth of the jaws. I will test this hypothesis by determining the function of components of the regulatory hub and their contributions to proper growth and form of the jaws. I will analyze necessity and function of orthologous sequences from zebrafish, chimp, and human, as well as determine the role of gbx2 in craniofacial morphology. Outcome measures include long-term assessment of CNCC migration and differentiation in vivo, and evaluating changes to spatiotemporal expression of gbx2 and related homeobox dlx genes in CNCCs and their derivatives. Findings from these experiments will lead to improved clinical strategies addressing disorders with disruptions to growth and form of the jaws as well as shed light on the contribution of coding and non-coding elements to craniofacial development and malformations.

项目概要头骨由不同胚胎起源的骨骼组成，这些骨骼通过关节连接包裹大脑，以保护大脑感觉器官，并促进咀嚼。精心策划的信号传导和形态事件产生颅面复合体的无缝形态。最重要的是颅神经嵴细胞（CNCC）从前神经皱襞迁移到口咽弓。 CNCC 收购中脑和后脑分割的轴向同一性。 CNCCs 基因表达的修饰，其前体、它们的衍生物、甚至相互作用的组织可能是正常变异和共同变异的基础颅面畸形。尽管控制 CNCC 早期规范的基因调控网络众所周知，我们仍然缺乏对涉及 CNCC 衍生品和后续发展事件的详细了解这与疾病的基本机制有何关系。该提案中概述的实验将戏弄除了基因型的形态学后果之外。我们预计基因座会改变相对比例头骨和面部在有颌脊椎动物中具有共同点，因为头部是祖先的特征。我们的先前的系统发育学比较确定了与差异性发育前颌相关的固定基因座。所鉴定的区域之一包含一个基因座，该基因座含有一个高度保守的大顺式调控区域。所有有颌脊椎动物。该基因座位于 agap1 的内含子中，并与在整个脊椎动物进化过程中，同源框基因 gbx2 是最近邻。这个 343 个碱基对 (bp) 区域是定义为脊椎动物之间具有超过 90% 的同一性。保留超过 190bp 的核心，100% 同一性在灵长类动物中，表明强烈的选择压力保留了深层保护，并且在人类发展。初步分析表明该地区可能参与更广泛的监管中心调节 gbx2 的表达。由于 gbx2 对于 CNCC 的图案化至关重要，并且表示为口咽弓，我的假设是，我们确定的保守非编码区域充当 gbx2 的特异性增强剂，介导形成拱门的模式并导致比例颌骨生长的变化。我将通过确定组件的功能来检验这个假设调节中心及其对颌骨正常生长和形状的贡献。我会分析必要性并斑马鱼、黑猩猩和人类的直系同源序列的功能，以及确定 gbx2 在颅面形态。结果措施包括对 CNCC 迁移的长期评估和体内分化，并评估 gbx2 和相关同源盒 dlx 时空表达的变化 CNCC 及其衍生物中的基因。这些实验的结果将导致临床策略的改进解决颌骨生长和形状受到破坏的疾病，并阐明颅面发育和畸形的编码和非编码元件。