Neural defects in zebrafish auditory/vestibular mutants

项目总结 大约四分之一的眩晕或眩晕患者有中枢性前庭障碍。 此外，听力损失或耳鸣可能是由中枢引起的。尽管中环地区普遍存在 患者听觉/前庭系统的缺陷，我们对中枢功能障碍的理解 脊椎动物的分子或细胞水平是缺乏的。在这里，我们打算描述一部小说的特征 斑马鱼突变体的一类，具有中枢听觉/前庭缺陷以获得对此的洞察 研究不足的领域。这项提案关注的是两个突变体：Raumschiff和Starliner， 它们是从化学诱变筛查中分离出来的，用于听力和平衡障碍。 与我们之前描述的突变体不同，raumschiff和Starliner突变体具有正常的 前庭诱发的眼睛运动，尽管表现出明显的平衡缺陷，而 游泳或休息。此外，这两个突变体都存在听力缺陷。我们有 确定了两个基因的突变：在Starliner突变体中，分裂末端(Spen)基因含有一个 无义突变和在raumschiff中我们发现了空泡蛋白的错义突变 排序4a(Vps4a)。对突变体和同胞转录本的RNAseq分析表明，这两个突变体 在后脑和中脑区域有明显的基因表达失调，但他们的 大脑发育和大体形态正常。这些结果表明，缺陷是 在本质上有功能，可能涉及电路水平或突触的变化。为了获得更好的 了解中心缺陷，我们将利用全鱼成像的优势表达 相关的转基因标记和使用新开发的细胞全脑成像方法 对听觉和前庭刺激的反应。这些实验将集中在区域或细胞上 基因表达失控最为普遍的类型。总体而言，我们的研究将 增强我们对参与中枢功能的基因和调控网络的理解。

PROJECT SUMMARY Approximately one quarter of patients with vertigo or dizziness have central vestibular disorders. In addition, hearing loss or tinnitus can have central origins. Despite the prevalence of central deficits in the auditory/vestibular system in patients, our understanding of central dysfunction at the molecular or cellular level in vertebrates is lacking. Here, we propose to characterize a novel class of zebrafish mutants that have central auditory/vestibular deficits to gain insights into this understudied area of research. This proposal focuses on two mutants: raumschiff and starliner, which were isolated from chemical mutagenesis screens for hearing and balance defects. Unlike our previously characterized mutants, raumschiff and starliner mutants have normal vestibular induced eye movements despite presenting with an obvious balance defect while swimming or at rest. In addition, a defect in hearing is present in both mutants. We have identified mutations in two genes: in starliner mutants, the split ends (spen) gene harbors a nonsense mutation and in raumschiff we identified a missense mutation in vacuolar protein sorting 4a (vps4a). RNAseq anaylsis of mutant and sibling transcripts indicate that both mutants have striking misregulation of gene expression in the hindbrain and midbrain regions, yet their development and gross brain morphology is normal. These results suggest that the defects are functional in nature and may involve circuit level or synaptic changes. To gain a better understanding of the central defects, we will take advantage of imaging whole fish expressing relevant transgene markers and use newly developed methods for brain-wide imaging of cellular responses to auditory and vestibular stimuli. These experiments will focus on the regions or cell types where misregulation of gene expression is most prevalent. Collectively our studies will enhance our understanding of the genes and regulatory networks involved in central function.