Identification of genes involved in photoreceptor recognition and synapse formation

项目总结/摘要 由光感受器死亡引起的视力丧失是不可逆失明的主要原因 然而，治疗选择仍然有限。因此，NEI的视网膜疾病计划 艾德将制定视网膜变性治疗策略确定为核心项目目标。 最近，几个实验室已经从干细胞中提取出光感受器， 特别有希望的治疗方法。此外，重要的进展已经进入操纵， 可以刺激视网膜米勒神经胶质细胞的视网膜再生这种成功的关键障碍是 治疗是将衍生的光感受器整合到现有的视网膜回路中，以重建它们的 功能然而，我们仍然缺乏一个完整的了解的机制，背后的正常布线， 光感受器进入视网膜回路，尤其是对于锥状光感受器。 不同亚型的视锥光感受器连接到特定的视网膜回路中， 差异（如光谱灵敏度）可以被利用来从图像中提取特定信息（如颜色）。 视觉场景我们对这一提议的主要假设是，每一种视锥细胞亚型都表达特定的基因， 允许其突触后伙伴（双极和水平细胞）识别，我们的主要目标是识别 这些基因。为了实现这一点，我们将首先生成四个基因的完整转录组学分析， 斑马鱼中不同的视锥细胞亚型，并确定差异表达的基因（目标1）。基于 这种差异表达，我们将进行反向遗传筛选，在那里我们将评估功能， 锥体突触的结构和超微结构完整性（目标#2）。这将使我们能够识别基因， 控制视锥细胞和其他视网膜细胞之间突触的形成， 视锥细胞整合到视网膜回路中。我们相信这些新知识可以直接应用于 用于改善视网膜变性的细胞替代或再生疗法。此外，布线 一般来说，特异性是神经回路的一个关键特征。这一建议贝内于实验 视网膜的可访问性和我们对视网膜细胞类型和电路的深入了解，但我们的方法具有 可能影响其他神经退行性疾病的研究。

PROJECT SUMMARY/ABSTRACT Vision loss caused by the death of photoreceptors is a leading cause of irreversible blindness worldwide, yet therapeutic options remain limited. For this reason, the NEI's Retinal Disease Program has identified the development of strategies for the treatment of retinal degenerations as a core program goal. Recently, several laboratories have derived photoreceptors from stem cells, making cell-replacement therapies particularly promising. Additionally, important advances have been made into manipulations that could stimulate retinal regeneration from the retinal Müller glia. The critical barrier for the success of such therapies is the integration of derived photoreceptors into existing retinal circuits to reestablish their function. Yet, we still lack a complete understanding on the mechanisms that underlie the normal wiring of photoreceptors into retinal circuits, especially for cone photoreceptors. Cone photoreceptors of different subtypes are wired into specific retinal circuits, so that functional differences (like spectral sensitivity) may be exploited to extract specific information (like color) from the visual scene. Our main hypothesis for this proposal is that each cone subtype expresses specific genes that allow recognition by its postsynaptic partners (bipolar and horizontal cells), and our main goal is to identify these genes. To accomplish this, we will first generate a complete transcriptomic profiling of the four different cone subtypes in zebrafish, and identify genes that are differentially expressed (aim #1). Based on this differential expression, we will perform a reverse-genetic screen, where we will assess the functional, structural and ultrastructural integrity of the cone synapses (aim #2). This will allow us to identify genes that control the control the formation of synapses between cones and other retinal cells, and that promote the integration of cones into retinal circuits. We believe that this new knowledge could have direct applications in the improvement of cell-replacement or regenerative therapies for retinal degenerations. Moreover, wiring specificity is a key feature of neural circuits in general. This proposal benefits from the experimental accessibility of the retina and our deep knowledge of retinal cell types and circuits, but our approach has the potential to impact the study of other neuronal degenerative diseases.