Role of the Foxe3 Gene Family in Lens Formation

描述（由申请人提供）：脊椎动物眼睛的发育需要一系列导致视网膜和透镜形成的发育事件，这些事件统称为眼球。除了眼球之外，还形成了眼球正常功能所需的眼睛相关结构，如角膜、泪腺、眼睑和结膜。我们的长期目标是确定每个脊椎动物眼睛结构正确形成所需的发育步骤和分子事件。在这个项目中，我们专注于前眼结构的发育，主要目的是了解透镜的发育。这个提议是我们以前研究的一个自然的延续，这些研究调查了包含叉头盒的基因Foxe 3在透镜形成中的作用，以及包含同源盒的基因Rx在视网膜形成中的作用。我们提出了以下具体目标，在未来五年：具体目标1是确定的发展命运和基因表达的头部表面外胚层在视网膜的情况下。在野生型胚胎中，侧头表面外胚层发育成透镜和辅助眼结构。在没有视网膜结构的Rx-/-胚胎中，透镜不发育。没有答案的问题仍然是辅助眼结构是否在没有视网膜和透镜的情况下发育。出于这个原因，在具体目标1的第一部分中，我们将确定辅助眼结构是否在Rx-/-胚胎中发育。在这个特定目标的第二部分中，我们将表征在没有视网膜的情况下侧头表面外胚层中的基因表达，并将其与野生型胚胎的头表面外胚层中的基因表达进行比较。这种比较将确定由视网膜协调的基因表达的变化，并导致透镜的形成。具体目的2是研究在视网膜存在和不存在的情况下观察到的头部表面外胚层中基因表达变化的功能意义。为此，我们将修改Rx-/-动物头部表面外胚层中的基因表达，并将监测透镜诱导以及透镜特异性基因表达。透镜基板的形成将被视为透镜命运的建立，而Foxe 3的表达将被视为透镜特异性基因表达的建立。具体目标3是通过宫内基因转移来纠正具有突变型Foxe 3功能的小鼠的分子和表型缺陷。为此，我们将使用病毒载体将野生型Foxe 3基因导入发育不良的透镜胚胎中。这些载体将携带野生型基因的Foxe 3调控和编码序列，并将通过子宫内基因转移递送至突变胚胎。该项目的目标是确定负责正常眼睛发育的基因和发育过程。对这些基因和发育过程的鉴定将有助于更好地了解眼病。因此，将开发新的眼科疾病诊断程序和治疗方法。

DESCRIPTION (provided by applicant): Development of the vertebrate eye requires a series of developmental events that lead to the formation of the retina and the lens, which are collectively called the eyeball. In addition to the eyeball, eye-associated structures such as the cornea, lacrimal gland, eyelid and conjunctiva are made that are required for the proper function of the eyeball. Our long-term goal is to identify developmental steps and molecular events necessary for the correct formation of each individual vertebrate eye structure. In this project, we are focusing on the development of anterior eye structures, with the primary aim to understand lens development. This proposal is a natural continuation of our previous studies investigating the role of the forkhead box-containing gene Foxe3 in lens formation, and the role of the homeobox-containing gene Rx in retinal formation. We propose the following specific aims for the next five years: Specific Aim 1 is to determine the developmental fate and gene expression of the head surface ectoderm in the absence of the retina. In wild type embryos, the lateral head surface ectoderm develops into the lens and auxiliary eye structures. In Rx-/- embryos, which have no retinal structures, the lens does not develop. The unanswered question remains whether auxiliary eye structures develop in the absence of the retina and the lens. For this reason, in the first part of specific aim 1, we will determine whether auxiliary eye structures develop in Rx-/- embryos. In the second part of this specific aim, we will characterize gene expression in lateral head surface ectoderm in the absence of the retina and compare it to gene expression in the head surface ectoderm of wild type embryos. This comparison will identify the changes in gene expression that are orchestrated by the retina, and lead to lens formation. Specific Aim 2 is to study the functional significance of the observed changes in gene expression in head surface ectoderm in the presence and absence of the retina. For this purpose, we will modify gene expression in the head surface ectoderm of Rx-/- animals and will monitor lens induction, as well as lens-specific gene expression. Formation of a lens placode will be viewed as the establishment of lens fate, and the expression of Foxe3, as the establishment of lens-specific gene expression. Specific Aim 3 is to correct the molecular and phenotypic defects in mice with mutant Foxe3 function by intrauterine gene transfer. For this purpose, we will introduce the wild type Foxe3 gene into dysgenetic lens embryos using viral vectors. These vectors will carry the Foxe3 regulatory and coding sequences of the wild type gene and will be delivered to the mutant embryos via intrauterine gene transfer. The goal of this project is to identify genes and developmental processes that are responsible for normal eye development. Identification of these genes and developmental processes will lead to the better understanding of eye diseases. As a result, new diagnostic procedures and treatments for eye diseases will be developed.