Factors Regulating Inner Ear Specification

调节内耳规格的因素

• 批准号: 7032780
• 负责人: Jean-Pierre Saint-Jeannet
• 金额: $ 26.95万
• 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/7032780
• 关键词: DNA binding protein; Wnt gene /protein; Xenopus; antisense nucleic acid; biological signal transduction; developmental genetics; embryogenesis; gene expression; genetic regulation; histology; labyrinth; nonmammalian vertebrate embryology; nucleoproteins; oligonucleotides; protein protein interaction; protein quantitation /detection; transcription factor; yeast two hybrid system

DESCRIPTION (provided by applicant): 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 Xenopus 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.

描述（由申请人提供）： 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。它是由称为耳片位置的胚胎外胚层的增厚。定义导致OIT斑块规范的分子过程对于了解内耳的发育至关重要。 SOX蛋白包括大量的转录调节剂。该家族的一位成员Sox9是软骨发生和性别确定的良好调节剂，也是假定的耳状位置中最早的基因之一。 SOX9中的突变导致campomelic发育不良（CD），这是一种致命的人类疾病，其特征是严重的骨骼畸形和XY性逆转。幸存下来的稀有CD患者的报告表明他们也受到感觉性耳聋的影响，这表明SOX9可能在听觉系统的发展中起重要作用。我们已经表明，在外胚层的感觉层初期，爪蟾中Sox9的耳片表达是启动的。在该组织中，Sox9表达受FGF和WNT信号传导调节，并与PAX8共定位，PAX8是对诱导信号的响应响应的最早基因之一。使用Morpholino反义寡核苷酸在整个胚胎中耗尽整个胚胎的耗竭会导致早期和晚期的耳效标志物急剧丧失，在最极端的情况下，这些胚胎未能形成形态上可识别的耳囊。以下实验将检验以下假设：转录因子SOX9是内耳规范所需的调节途径的关键组成部分。我们提出：1来定义OIT斑点中SOX9表达的分子调节剂，通过在Otocode中激活SOX9表达的信号的起源。并定义FGF和WNT信号传导对整个胚胎和动物外植体中耳模式规格的需求和充分性。 2要表征异武士Sox9缺乏的胚胎的耳朵表型3-鉴定使用酵母双杂交筛选在眼部斑点中的Sox9相互作用伴侣分子，因为已知Sox蛋白可以通过与细胞类型的伴侣的形式相互作用来调节其靶基因，从而使其与此类伴侣的形式相互作用。 耳朵。