SENSORY ORGAN FORMATION/ GENE EXPRESSION --INNER EAR DEVELOPMENT

本研究的目的是阐明内耳发育过程中感觉器官形成的细胞和分子过程。本研究以非洲爪蟾（Xenopus laevis）和热带爪蟾（Xenopus (Silurana) tropicalis）的听觉和前庭系统为实验模型。研究结果有望提供关于三种内耳内器官：小囊（一种听觉前庭器官）和两栖动物乳头（一种听觉器官）的结构、生长和遗传谱的比较数据。实验将集中于周围神经系统的细胞：机械感觉毛细胞和感觉神经节细胞。这项研究的一个主要长期目标是开发鉴定内耳中表达的新基因的技术和方法。具体目的是：(1)获得鉴定内耳中表达的新基因的方法。具体目的是：(1)获得小囊、两栖动物乳头和小囊感觉上皮细胞发育过程中模式形成的比较数据；(2)确定耳朵发育过程中毛细胞和感觉神经节细胞产生的位点；(3)合成热带苍耳和热带苍耳内耳cDNA文库；(4)分析内耳cDNA文库克隆的基因表达模式。本研究使用的方法包括RT-PCR引导cDNA文库构建、从少量内耳组织中分离RNA、原位杂交、生物信息学和多光子激光扫描共聚焦显微镜。实验结果将为了解毛细胞在感觉器官形成过程中的分化和增殖模式提供基础数据，并有助于进一步了解内耳发育过程中的基因表达。本研究的长期目标是确定内耳中表达的新基因的功能，并确定内耳中表达的基因在发育、再生和衰老过程中是如何被调节的。这些调查的结果将提供必要的知识，可用于开发有效的治疗遗传性和环境引起的听力和平衡障碍。

The goal of this research is to elucidate the cellular and molecular processes that underlie sensory organ formation during inner ear development. The proposed research will use the auditory and vestibular system of Xenopus laevis and Xenopus (Silurana) tropicalis as experimental models. Results are expected to provide comparative data about the structure, growth, and genetic profile of three inner ear endorgans: the sacculus (an acoustico-vestibular organ) and the amphibian papilla (an acoustic organ). Experiments will focus on cells of the peripheral nervous system: mechanosensory hair cells and sensory ganglion cells. A major long term goal of this research is to develop technologies and methods for identifying novel genes expressed in the inner ear. The specific aims are: (1) to obtain methods for identifying novel genes expressed in the inner ear. The specific aims are: (1) to obtain comparative data about pattern formation during development of the sensory epithelial of the utricle, amphibian papilla, and sacculus, (2) to identify the sites of hair cell and sensory ganglion cell production during ear development, (3) to synthesize cDNA libraries from the inner ear of X. laevis and X. tropicalis, and (4) to analyze gene expression patterns of inner ear cDNA library clones. Methods used in this research include RT-PCR directed cDNA library construction, isolation of RNA from small quantities of inner ear tissue, in situ hybridization, bioinformatics, and multi-photon laser scanning confocal microscopy. Experimental results will provide fundamental of data about the pattern of hair cell differentiation and proliferation during sensory organ formation and will advance understanding of gene expression during inner ear development. The long term goal of this research is to identify the function of novel genes expressed in the inner ear, and to determine how genes expressed in the inner ear are regulated during development, regeneration, and aging. Results of these investigations will provide essential knowledge that can be used to develop effective treatments for hereditary and environmentally-induced disorders of hearing and balance.