Factors Regulating Inner Ear Specification

调节内耳规格的因素

• 批准号: 7534356
• 负责人: Jean-Pierre Saint-Jeannet
• 金额: $ 25.82万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-14 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7534356
• 关键词: Acceleration; Adolescence; Affect; Animals; Antisense Oligonucleotides; Auditory system; Binding; Biological Assay; Candidate Disease Gene; Cells; Chondrocytes; Chondrogenesis; Cities; Detection; Development; Disease; Ear; Ectoderm; Embryo; Embryonic Development; Equilibrium; Face; Family member; Gene Expression Regulation; Gene Targeting; Genes; HMG Domain; HMG-Box; Hearing; Histology; Human; Human Resources; Injection of therapeutic agent; Instruction; Labyrinth; Ligands; Mediating; Modeling; Molecular; Mutation; Names; Organ; Otic Placodes; Otic Vesicle; Paint; Paraxial Mesoderm; Patients; Pennsylvania; Phenotype; Philadelphia; Play; Principal Investigator; Printing; Process; Proteins; Pus; Regulatory Pathway; Reporting; Research Personnel; Research Project Grants; Role; Saints; Schools; Sensorineural Hearing Loss; Sensory; Signal Transduction; Site; Testing; Tissue Recombination; Tissues; Universities; Veterinary Medicine; Xenopus; Yeasts; campomelic dysplasia; cell type; hindbrain; malformation; mutant; programs; protein expression; research study; response; sertoli cell; sex; sex determination; skeletal; three dimensional structure; transcription factor; yeast two hybrid system

The vertebrate inner ear is a sensory organ implicated in hearing, balance and detection of acceleration. It develops from a thickening of the embryonic ectoderm known as the otic placode. Defining the molecular processes leading to specification of the otic placode is essential to understand inner ear development. Sox proteins comprise a large class of transcriptional regulators. One member of this family, Sox9, a well- established regulator of chondrogenesis and sex determination, is also one of the earliest genes expressed in the presumptive otic placode. Mutations in Sox9 result in campomelic dysplasia (CD), a fatal human disorder characterized by severe skeletal malformations and XY sex reversal. Reports of rare CD patients that survived indicate that they are also affected with sensorineural deafness, suggesting that Sox9 may play an important role in the development of the auditory system. We have shown that the otic expression of Sox9 in Xenopus is initiated early in the sensory layer of the ectoderm. In this tissue, Sox9 expression is regulated by Fgf and Wnt signaling and co-localizes with Pax8, one of the earliest gene expressed in response to otic placode inducing signals. Depletion of Sox9 protein in whole embryos using morpholino antisense oligonucleotides causes a dramatic loss of early and late otic markers, and in the most extreme cases these embryos fail to form a morphologically recognizable otic vesicle. The experiments below will test the following hypothesis: the transcription factor Sox9 is a key component of regulatory pathway required for inner ear specification. We propose: 1-To define the molecular regulators of Sox9 expression in the otic placode by establishing the origin of the signals activating Sox9 expression in the otic placode; and defining the requirement and sufficiency of Fgf and Wnt signaling for otic placode specification in whole embryos and animal explants. 2-To characterize the ear phenotype of Xenpopus Sox9-deficient embryos 3-To identify Sox9-interacting partner molecules in the otic placode using a yeast two-hybrid screen, since Sox proteins are known to regulate their target genes through interaction with cell type-specific partner molecules.The characterization of such partner molecules should further our understanding of Sox9-mediated gene regulation in the context of the developing inner ear.

脊椎动物内耳是一种感官器官，涉及听力，平衡和检测加速度。它 从称为耳片的胚胎外胚层的增厚。定义分子 导致OTOT PLACODE规范的过程对于了解内耳的发展至关重要。 SOX蛋白包括大量的转录调节剂。这个家庭的一个成员Sox9，一个很好的 已建立的软骨发生和性别确定的调节剂也是最早的基因之一 推定的耳片位置。 Sox9突变导致campomelic发育不良（CD），一种致命的人类疾病 以严重的骨骼畸形和XY性逆转为特征。稀有CD患者的报告 幸存的表明它们也受到感觉性耳聋的影响，这表明Sox9可能会发挥作用 在听觉系统的开发中的重要作用。 我们已经表明，在爪蟾中Sox9的耳片表达是在早期的感觉层的早期开始的 外胚层。在该组织中，Sox9表达受FGF和Wnt信号的调节，并与PAX8共定位， 最早的基因之一是对诱导信号的响应。 Sox9蛋白的耗竭 使用吗啡反义寡核苷酸的整个胚胎会引起早期和晚期的巨大丧失 标记，在最极端的情况下，这些胚胎无法形成形态学上可识别的耳 囊泡。以下实验将检验以下假设：转录因子SOX9是关键 内耳规格所需的调节途径的组成部分。 我们提出：1通过建立OIT斑点中Sox9表达的分子调节剂 信号激活Sox9表达的信号的起源；并定义要求和 FGF和WNT信号的充分性，用于整个胚胎和动物外植体中的OTIC Placode规范。 2以表征Xenpopus sox9缺陷胚胎的耳朵表型3识别Sox9相互作用 使用酵母双杂交筛网中的伴侣分子，因为已知Sox蛋白已知 通过与细胞类型特异性伴侣分子相互作用来调节其靶基因。 这种伴侣分子应进一步了解我们对Sox9介导的基因调节的理解 发展内耳。