Role of the Lens1/Foxe3 Gene Family in Lens Formation

描述(申请人提供)：晶状体的形成需要几个信号分子和转录调节因子的相互作用。其中之一是小鼠叉头蛋白Foxe3及其非洲爪哇功能同源物Xlens1。我们以前已经证明，Foxe3在晶状体形成的最早阶段就有表达，而Foxe3的突变是小鼠晶状体发育异常(DYL)表型的原因。人类FOXE3基因突变可导致眼前段发育不全和白内障。Xlens1的过表达干扰了晶状体纤维细胞的正常分化，导致晶状体前上皮细胞过度增殖。本研究的目的是确定Foxe3/lens1基因家族的功能和调控元件。我们提出了以下与晶状体形成相关的具体目标。 具体目的1：鉴定参与Foxe3转录调控的蛋白质。这一特定目的的目的是分离与Foxe3调节区结合的蛋白质，因此很可能是Foxe3转录的直接调节因子。 具体目的2.分析Foxe3/XLens1功能缺失时晶状体的发育。Foxe3功能的消除对晶状体发育和晶状体特异性基因表达的影响将在Foxe3“基因敲除”小鼠中进行监测。将针对Xlens1翻译起始区的吗啡注射到非洲爪哇胚胎中，可以消除Xlens1的功能。这些实验将确定Xlens1活性的消除对源自前胎盘区域的结构发育的影响。 具体目的3.通过宫内基因转移纠正发育不良晶状体突变小鼠的分子和表型缺陷。为了实现这一目标，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Foxe3调控和编码序列，并将通过宫内基因转移传递给突变胚胎。

DESCRIPTION (provided by applicant): Lens formation requires the interaction of several signaling molecules and transcriptional regulators. One of them is the murine forkhead protein Foxe3 and its Xenopus functional homologue Xlens1. We have shown previously that Foxe3 is expressed during the earliest stages of lens formation, and mutations in Foxe3 are the cause of the dysgenetic lens (dyl) phenotype in mouse. Mutations in human FOXE3 can cause anterior segment dysgenesis and cataracts. Overexpression of Xlens1 interferes with normal differentiation of lens fiber cells and results in overproliferation of cell in the anterior lens epithelium. The goal of this research is to identify the function and regulatory elements of Foxe3/Lens1 gene family. We propose the following specific aims related to lens formation. Specific Aim 1: Characterization of proteins that are involved in regulation of Foxe3 transcription. The goal of this specific aim is to isolate proteins that bind to the Foxe3 regulatory region and therefore are likely to be direct regulators of Foxe3 transcription. Specific Aim 2. Analysis of lens development in the absence of Foxe3/Xlens 1 function. The effects of elimination of Foxe3 function on development of the lens and on lens specific gene expression will be monitored in Foxe3 "knockout" mice. Elimination of Xlens1 function will be achieved by injection of Xenopus embryos with morpholinos directed against the translation initiation region of Xlens1. These experiments will determine the consequences of elimination of Xlens1 activity on development of structures derived from the anterior placodal region. Specific Aim 3. Correction of molecular and phenotypic defects in dysgenetic lens mutant mice by intrauterine gene transfer. In order to achieve this goal, we will introduce the wild type Foxe3 gene into dysgenetic lens embryos using viral vectors. These vectors will carry the wild type Foxe3 regulatory and coding sequences and will be delivered to the mutant embryos via intrauterine gene transfer.