RX HOMEOBOX GENE AND RETINAL FORMATION

脊椎动物眼睛的形成是一个复杂的过程， 前神经板的规格， 视泡和透镜的细胞分化， 视网膜。 这些发展过程中的每一个都可能是 通过转录调节因子的相互作用介导， 因子及其受体。 本研究的目的是 确定在基因和过程中发挥关键作用， 眼睛形成的最初阶段。 具体重点将是 放置在同源框基因Rx的作用，在形成 视网膜前体细胞和视网膜干细胞的维持 细胞 我们已经发现Rx对于正常眼睛是必需的 发展及其错误表达对眼睛有着深远的影响 形态学 注射Rx RNA的非洲爪蟾胚胎发生异位发育 视网膜组织，并在神经视网膜中显示过度增殖。 携带该基因无效等位基因的小鼠胚胎不会形成 视杯，因此不发育眼睛。 鉴于至关重要的 Rx在眼睛发育过程中的作用，我们提出了三个具体的 与其在视网膜形成过程中的功能相关的目标： 具体目标1：Rx调节途径的研究。 这将是 通过分析非洲爪蟾胚胎中的基因表达， 通过分析基因表达， 在Rx无效小鼠突变体中。 具体目标2： 指导Rx表达进入视网膜祖细胞的序列 细胞和视网膜干细胞。 为此，我们将结扎 Rx基因的5'侧翼区与β-半乳糖苷酶 报告人制度 使用该构建体制备的转基因小鼠将 监测β-半乳糖苷酶的眼特异性表达。 具体目标3：视网膜干细胞永生化。 视网膜 干细胞将通过融合Rx调节因子 将Rx编码序列连接至SV 40 T抗原或通过将Rx编码序列连接至SV 40 T抗原来实现 到组成型激活的启动子。 这一研究对于更好地理解正常的 和异常的眼睛发育，如无眼症， 小眼症，并可能为我们提供信息， 需要更换视网膜细胞在退化的眼睛 视网膜干细胞移植

Vertebrate eye formation is a complex process that requires specification of the anterior neural plate, formation of the optic vesicle, and cellular differentiation of the lens and retina. Each of these developmental processes is likely to be mediated by an interaction of transcriptional regulators, growth factors and their receptors. It is the goal of this research to identify genes and processes that play a critical role in the initial stages of eye formation. Specific emphasis will be placed on the role of the homeobox gene Rx in the formation of retinal progenitor cells and in the maintenance of retinal stem cells. We have found that Rx is essential for normal eye development and its misexpression has profound effects on eye morphology. Xenopus embryos injected with Rx RNA develop ectopic retinal tissue and display hyperproliferation in the neuroretina. Mouse embryos carrying a null allele of this gene do not form optic cups and consequently do not develop eyes. Given the vital role of Rx during eye development, we propose three specific goals related to its function during retinal formation: Specific aim 1: Study of the Rx regulatory pathway. This will be achieved by analyzing gene expression in Xenopus embryos and animal caps injected with Rx RNA and by analyzing gene expression in Rx null mouse mutant. Specific aim 2: Characterization of sequences that direct Rx expression into the retinal progenitor cells and retinal stem cells. For this purpose we will ligate the 5' flanking regions of the Rx gene to Beta-galactosidase reporter system. Transgenic mice made using this construct will be monitored for eye specific expression of Beta-galactosidase. Specific aim 3: Immortalization of retinal stem cells. Retinal stem cells will be immortalized either by fusing Rx regulatory sequences to the SV40 T antigen or by linking Rx coding sequences to a constitutively activated promoter. This research is of importance for better understanding of normal and abnormal eye development such as anophthalmia and microphthalmia, and is likely to provide us with information necessary for replacement of retinal cells in degenerative eye diseases using retinal stem cell population.