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的发育事件，导致视网膜和晶状体的形成，它们统称为眼球。除了眼球外，眼睛的相关结构，如角膜、泪腺、眼睑和结膜都是眼球正常功能所必需的。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，我们专注于眼前结构的发育，主要目的是了解晶状体的发育。这一建议是我们之前的研究的自然延续，研究了包含叉头盒的基因Foxe3在晶晶体形成中的作用，以及包含同源盒的基因Rx在视网膜形成中的作用。我们提出未来五年的具体目标如下：具体目标1是确定在视网膜缺失的情况下头表面外胚层的发育命运和基因表达。在野生型胚胎中，侧头表面外胚层发育为晶状体和辅助眼睛结构。在没有视网膜结构的Rx-/-胚胎中，晶状体不会发育。没有答案的问题仍然是辅助眼睛结构是否在没有视网膜和晶状体的情况下发育。因此，在具体目标1的第一部分，我们将确定辅助眼结构是否在Rx-/-胚胎中发育。在这一特定目标的第二部分，我们将描述在没有视网膜的情况下，侧头表面外胚层的基因表达，并将其与野生型胚胎头表面外胚层的基因表达进行比较。这种比较将确定由视网膜组织的基因表达的变化，并导致晶状体的形成。特异性目的2是研究在视网膜存在和不存在的情况下观察到的头表面外胚层基因表达变化的功能意义。为此，我们将修改Rx-/-动物头表面外胚层的基因表达，并将监测晶状体诱导以及晶状体特异性基因表达。晶状体基板的形成将被视为晶状体命运的建立，Foxe3的表达将被视为晶状体特异性基因表达的建立。具体目的3是通过宫内基因转移来纠正Foxe3功能突变小鼠的分子和表型缺陷。为此，我们将利用病毒载体将野生型Foxe3基因导入发育不良的晶状体胚胎。这些载体将携带野生型基因的Foxe3调控和编码序列，并通过宫内基因转移传递到突变胚胎中。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。鉴定这些基因和发育过程将有助于更好地了解眼病。因此，新的眼病诊断程序和治疗方法将被开发出来。

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.