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期间，透镜由假定的视网膜神经外胚层诱导从头部表面外胚层形成。当外翻视泡接触外胚层表面时，外胚层增厚并形成透镜基板。在哺乳动物中，透镜基板内陷并形成透镜囊泡。后透镜细胞停止增殖并分化为透镜纤维细胞。前透镜细胞形成相对未分化的、增殖活跃的透镜上皮。我们的长期目标是确定透镜形成所需的发育步骤和分子事件。本研究的主要焦点是叉头基因Foxe3的作用和作用机制。这项研究是我们以前研究该基因在透镜形成中作用的自然延续。 由于透镜细胞的正常发育和维持对视力至关重要，因此必须确定控制透镜细胞发育和存活的发育过程和基因网络。透镜细胞的形成、增殖和分化受多个关键基因控制。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的异常透镜发育。Foxe3功能的缺失导致透镜细胞增殖、分化和存活的变化。Foxe3的丢失如何导致所有这些变化在很大程度上仍然未知。由于Foxe3是一种转录因子，其对透镜细胞的生理和形态的影响必须由其他基因介导。除了少数例外，Foxe3的下游介质尚不清楚。为了更好地理解Foxe3如何调节透镜发育以及为什么该基因中的突变导致如此显著异常的透镜发育，我们将在具体目标1中通过使用深度RNA测序比较野生型和Foxe3缺陷晶状体的转录组来鉴定属于Foxe3透镜调控网络的基因。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尖端技术将帮助我们鉴定在透镜发育过程中介导Foxe3功能的基因。 在特定目标3中，我们将使用子宫内基因治疗来纠正突变或缺失Foxe3的小鼠的分子和表型透镜缺陷。 这项研究将导致更好地了解透镜的发展，因为这个基因是调节早期的关键步骤，透镜的形成。然而，由于该基因的突变会导致小鼠和人类眼睛发育异常，因此这项研究将有助于更好地诊断和治疗Foxe3调控网络的组成部分发生突变的眼部疾病。

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.