Molecular Biology of Retinal Development

描述(申请人提供)：这个项目的长期目标是阐明脊椎动物视网膜中光感受器产生的分子调控。这一知识对于开发有效的基于干细胞的光感受器替代疗法是必不可少的。关于涉及的基因的身份，以及它们如何有助于从其他选择中选择光感受器命运，需要了解很多。在之前的资金支持期间，研究发现，在Ngn2-&Gt；Neurod-&gt；RaxL的转录途径中，Neurd是光感受器分化的一个重要角色。在这个途径中，Ngn2在多能祖细胞中发挥作用，其下游的遗传靶标包括Neurod；Neurod引发光感受器的发育程序，包括同源框基因RaxL的表达。在这一应用中，我们将测试假设，光感受器生产使用Ngn1在Ngn2和NeuD之间的关键步骤。目的1检测Ngn1是否在正确的地点和正确的时间表达，成为引导祖细胞进入光感受器通路的主要基因。目的2研究Ngn1是否明确地引导祖细胞进入光感受器途径，从而独占地导致光感受器的产生。目的3确定Ngn1是否是光感受器产生所必需的。目的4阐述在光感受器产生过程中，Ngn1如何在基因上与Ngn2和Neurd相关。这些研究将利用分子生物学、细胞生物学、发育生物学和遗传学的一系列技术进行。这个项目有望阐明控制光感受器产生的转录调控。此外，它还具有临床意义。识别光感受器产生的关键遗传因素将使具有治疗目标的研究在体外或体内有效地产生光感受器。在这个干细胞研究替代疗法的兴趣高涨的时代，这些研究是及时的。

DESCRIPTION (provided by applicant): The long-term goal of this project is to elucidate the molecular regulation of photoreceptor production in the vertebrate retina. This knowledge is imperative to the development of effective stem cell-based photoreceptor replacement therapies. Much needs to be learned about the identities of the genes involved and how they contribute to the selection of the photoreceptor fate from among the other options. Studies during the previous funding period identified neuroD as an instrumental player in photoreceptor differentiation, in a transcriptional pathway of ngn2->neuroD->RaxL. In this pathway, ngn2 functions in multipotent progenitors and its downstream genetic targets include neuroD; neuroD elicits a photoreceptor development program, including the expression of homeobox gene RaxL. In this application we will test the hypothesis that photoreceptor production employs ngn1 at a key step between ngn2 and neuroD. Aim 1 examines whether ngn1 is expressed at the right place and the right time to be a major gene in leading progenitors to the photoreceptor path. Aim 2 investigates whether ngn1 expressly steers progenitors to the photoreceptor path and, thus, leads exclusively to photoreceptor production. Aim 3 determines whether ngn1 is required for photoreceptor production. Aim 4 addresses how ngn1 genetically relates to ngn2 and neuroD during photoreceptor production. These studies will be carried out with a battery of techniques from molecular biology, cell biology, developmental biology, and genetics. This project promises to shed light on the transcriptional regulation governing photoreceptor production. Furthermore, it bears clinical implications. The identification of key genetic players in photoreceptor production will capacitate efficient in vitro or in vivo photoreceptor generation for studies with therapeutic goals. These studies are timely in this era of heightened interest in stem cell research for replacement therapies.