DEVELOPMENTAL REGULATION OF INNER EAR CELL FATE

内耳是一个复杂的感觉器官，其功能对许多导致先天性耳聋、听力障碍或前庭功能障碍的遗传和环境因素很敏感。了解内耳感觉结构的形成和功能将是制定改善或逆转内耳功能缺陷策略的基础。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（狗耳，狗；前庭感觉上皮形成缺陷）斑马鱼胚胎，将实现以下具体目标：1)利用笼状荧光素的局部激活，开发高分辨率的耳位和早期耳囊的命运图。这张图将确定早期耳朵的区域，这些区域将产生48小时耳囊肿的五个正在发育的感觉上皮。2)完成犬突变与发育中的耳感觉上皮中基因表达模式的表征。3)通过细胞移植检测犬的细胞自主性表型和细胞对感觉上皮命运的承诺时间。4)建立定位杂交，确定犬基因的基因组位置。这些目标将提供在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片，并导致最终克隆狗基因。

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.