Neuronogenesis in the Non-pigmented Retina

描述(申请人提供)：哺乳动物，包括人类，在视网膜色素上皮细胞中缺乏色素，有许多视网膜和视觉系统的异常。类似的异常发生在包括眼睛在内的全身缺乏色素的白化病患者和只有眼睛缺乏色素的眼部白化患者中。我们认为，在神经视网膜发育的早期，色素的缺乏影响细胞的增殖，这些细胞增殖的异常影响成年视网膜的细胞数量和细胞类别。我们描述了一组假设的视网膜增殖细胞在有色人眼和无色人眼中的行为，然后提出了具体的实验来检验这一假设。在这个项目中，将使用两种不同类型的无色素视网膜的小鼠：C57BL/6J-tyrc2J/tyrc2J白化小鼠和Oa1tm1Inc/Y白化小鼠。这些小鼠在色素处理途径的不同位置有突变，而且两者的表型都与它们的人类同行基本相似。Oa1tmInc.小鼠是人类OA1(也称为Nettlesship-Falls型眼白化病)的小鼠同源物。我们将使用的有色小鼠被选择为具有与非有色小鼠相同的遗传背景。该项目有三个特定的目标，将以高空间和时间分辨率检查：1)细胞周期，2)子代细胞离开和保留在细胞周期中的比例，以及3)特定视网膜类别细胞的产生。我们将使用本实验室开发的方法实现该项目的高空间和时间分辨率，该方法利用两个S相标记物-溴脱氧尿嘧啶核苷和氚胸苷的双重标记。所获得的结果将告诉我们有色和无色动物在发育中视网膜细胞产生的最早差异，包括视网膜内区域差异的信息。这些详细的信息对于理解视网膜色素缺乏如何导致异常以及治疗和治疗的基本原理是重要的。

DESCRIPTION (provided by applicant): Mammals, including humans, lacking pigment in the retinal pigment epithelial cells have a number of abnormalities of the retina and visual system. Similar abnormalities occur in albinos that lack pigment in the entire body including the eye and in ocular albinos that lack pigment only in the eye. We propose that the lack of pigment affects cell proliferation early in the development of the neural retina and that these abnormalities in cell proliferation affect both cell number and cell class in the adult retina. We describe a hypothetical set of behaviors for the proliferating cells of the retina in pigmented vs non-pigmented eyes and then propose specific experiments to test this hypothesis. For this project mice with two different types of non-pigmented retinas will be used: C57BL/6J-tyrc2J/tyrc2J, which are albino, and Oa1tm1Inc/Y which are ocular albinos. These mice have mutations at different locations in the pigment processing pathway, and both have phenotypes that are substantially similar to their human counterparts. The Oa1tmInc mouse is a murine homolog of human Oa1 (also known as Nettleship-Falls Type Ocular Albinism). The pigmented mice that we will use are chosen to have the same genetic background as the non-pigmented mice. The project has 3 specific aims which will examine at high spatial and temporal resolution: 1) the cell cycle, 2) the proportion of daughter cells leaving vs remaining in the cell cycle, and 3) the generation of cells of specific retinal classes. We will achieve both high spatial and temporal resolution for this project using methods developed in this laboratory that exploit double labeling with two S-phase markers, bromodeoxyuridine and tritiated thymidine. The results obtained will tell us the earliest differences in the production of cells in the developing retina for pigmented and non-pigmented animals including information about regional differences within the retina. Such detailed information is important for understanding how the lack of retinal pigment produces abnormalities and for the rationale development of treatments and therapies.