DEVELOPMENTAL REGULATION OF INNER EAR CELL FATE

内耳是一个复杂的感觉器官，其功能对导致先天性耳聋、听力障碍或前庭功能障碍的许多遗传和环境因素很敏感。对内耳感觉结构如何形成和功能的了解将是制定改善或逆转内耳功能缺陷的策略的基础。该项目的目标是确定控制内耳感觉细胞结构模式和发育的分子遗传途径。利用野生型和突变型(狗；在前庭感觉上皮形成中存在缺陷)斑马鱼胚胎，将追求以下特定目标：1)利用笼中荧光素的局部激活，开发耳道胎盘和早期耳囊的高分辨率命运图。这张图将识别早期耳朵的区域，这些区域将产生48小时耳囊的五个发育中的感觉上皮细胞。2)根据发育中的耳朵感觉上皮细胞的基因表达模式，完成狗突变的特征。3)检测犬细胞自主性的表型和细胞与感觉上皮结合的时机。4)建立作图杂交以确定狗基因的基因组位置。这些目标将提供内耳感觉结构形成之前的细胞生物学和分子遗传学事件的详细图景，并最终导致狗基因的克隆。

The inner ear is a complex sensory organ whose function is sensitive to a number of genetic and environmental factors that lead to congenital deafness, hearing impairment, or vestibular dysfunction. An understanding of how inner ear sensory structures are formed and function will be fundamental to developing strategies to ameliorate or reverse deficits of inner ear function. The goal of this project is to identify molecular genetic pathways that control patterning and development of sensory cell structures in the inner ear. Utilizing wild-type and mutant (dog-eared, dog; that is defective in vestibular sensory epithelium formation) zebrafish embryos the following specific aims will be pursued: 1) Develop a high resolution fate map of the otic placode and early otic vesicle using the local activation of caged fluorescein. This map will identify areas of the early ear that will give rise to the five developing sensory epithelia of the 48hr otocyst. 2) Complete the characterization of the dog mutation with respect to patterns of gene expression in the developing sensory epithelia of the ear. 3) Test for cell autonomy of the dog phenotype and timing of cell commitment to the sensory epithelium fate by cell transplantations. 4) Establish mapping crosses to identify the genomic location of the dog gene. These aims will provide a detailed picture of the cell biological and molecular genetic events that precede sensory structure formation in the inner ear and lead to the eventual cloning of the dog gene.