Role of the Foxe3 Gene Family in Lens Formation.

描述（由申请人提供）：在早期脊椎动物发育过程中，晶状体由假定的视网膜神经外胚层诱导从头部表面外胚层形成。当外翻的视神经囊泡接触外胚层表面时，外胚层增厚并形成晶状体基板。在哺乳动物中，晶状体基板内陷并形成晶状体囊泡。晶状体后细胞停止增殖，分化为晶状体纤维细胞。晶状体前细胞形成相对未分化、增生活跃的晶状体上皮。我们的长期目标是确定晶状体形成所需的发育步骤和分子事件。本研究的重点是叉头基因Foxe3的作用和作用机制。这项研究是我们之前研究该基因在晶状体形成中的作用的自然延续。由于晶状体细胞的正常发育和维持对视力至关重要，因此确定晶状体细胞发育和存活的发育过程和基因网络是必要的。几个关键基因控制晶状体细胞的形成、增殖和分化。其中之一是叉头基因Foxe3。该基因编码一种转录因子，该基因的突变导致小鼠和人类晶状体发育异常。Foxe3功能缺失导致晶状体细胞的增殖、分化和存活发生变化。Foxe3基因的缺失是如何导致所有这些变化的，目前还不得而知。由于Foxe3是一种转录因子，其对晶状体细胞生理和形态的影响必须由其他基因介导。除了少数例外，Foxe3的下游介质是未知的。为了更好地理解Foxe3调控晶状体发育的机制，以及该基因突变导致晶状体发育异常的原因，我们将在Specific Aim 1中使用深度rna测序技术，通过比较野生型和Foxe3缺陷型晶状体的转录组，鉴定属于Foxe3晶状体调控网络的基因。在Specific Aim 2中，我们将通过染色质免疫沉淀结合测序来鉴定Foxe3的直接靶基因。这些分子和发育生物学的前沿技术将帮助我们识别在晶状体发育过程中介导Foxe3功能的基因。在Specific Aim 3中，我们将使用子宫内基因治疗来纠正Foxe3突变或缺失小鼠晶状体的分子和表型缺陷。这项研究将有助于更好地理解晶状体的发育，因为这种基因正在调节晶状体形成的早期关键步骤。然而，由于该基因的突变导致小鼠和人类的眼睛发育异常，因此这项研究将使人们能够更好地诊断和治疗Foxe3调节网络的组成部分发生突变的眼睛疾病。

DESCRIPTION (provided by applicant): During early vertebrate development, lens is induced to form from the head surface ectoderm by the presumptive retinal neuroectoderm. When the evaginating optic vesicle contacts the surface ectoderm, the ectoderm thickens and forms a lens placode. In mammals, the lens placode invaginates and forms the lens vesicle. The posterior lens cells stop proliferation and differentiate into lens fiber cells. The anterior lens cells form a relatively undifferentiated, proliferatively active lens epithelium. Our long-term goal is to identify developmental steps and molecular events necessary for lens formation. The primary focus of this research is the role and the mechanism of action of the forkhead gene Foxe3. This research is a natural continuation of our previous studies investigating the role of this gene in lens formation. Since normal development and maintenance of lens cells is critical for vision, it is essential to define the developmental processes and gene networks that govern the development and survival of lens cells. Several key genes control of the formation, proliferation and differentiation of lens cells. One of them is the forkhead gene Foxe3. This gene encodes a transcription factor and mutations in this gene cause abnormal lens development in mouse and human. The absence of Foxe3 function leads to changes in the proliferation, differentiation and survival of lens cells. How the loss of Foxe3 leads to all of these changes remains largely unknown. Since Foxe3 is a transcription factor, its effects on the physiology and morphology of lens cells has to be mediated by other genes. With few exceptions, the downstream mediators of Foxe3 are not known. To better understand how Foxe3 regulates lens development and why mutations in this gene lead to such dramatically abnormal lens development, we will in Specific Aim 1 identify genes that belong to the Foxe3 lens regulatory network by comparing transcriptomes of wild type and Foxe3-deficient lenses using deep RNA-sequencing. In Specific Aim 2, we will identify direct target genes of Foxe3 by chromatin immunoprecipitation combined with sequencing. These cutting edge techniques in molecular and developmental biology will help us identify genes that mediate Foxe3 function during lens development. In Specific Aim 3, we will correct the molecular and phenotypic lens defects in mice with mutant or absent Foxe3 using in utero gene therapy. This research will lead to a better understanding of lens development, as this gene is regulating the early critical steps in lens formation. However, since mutations in this gene cause abnormal eye development in mouse and human, this research will result in knowledge that will allow a better diagnosis and treatment of diseases of the eye in which the components of the Foxe3 regulatory network are mutated.