MOLECULAR AND CELLULAR BASIS OF LENS DEVELOPMENT

描述：胚胎发生是一个复杂的过程， 细胞，即受精卵，产生多细胞的成体有机体。 在脊椎动物胚胎中，特定的组织相互作用，称为诱导 相互作用，在决定各种细胞命运中发挥重要作用。 的 这项研究的总体目标是了解分子和细胞 这些过程的基础。 脊椎动物透镜的发展已经成为一种模式 审查这些事件的系统，因为这个机构的发展， 是由一系列特定的组织相互作用引发的 的成功 该系统是由于其可直接进行实验操作， 尤其是在两栖动物的胚胎中。 尽管PI对以下内容有着深刻的理解： 脊椎动物透镜诱导中涉及的组织相互作用， 关于透镜细胞过程的分子基础是已知的 决定，或参与透镜诱导的信号分子。 这些问题是本研究提案的主要重点。 继续努力 将致力于确定基因表达的特定变化， 与透镜细胞的决定和分化过程有关 使用来自非洲爪蟾的。 爪蟾幼虫的角膜 转分化以形成透镜。 大量证据表明， 这一过程与胚胎透镜的发育有关， 分子和细胞水平。 角膜-晶状体现象 转分化代表了一种更方便的系统， 分离参与透镜细胞决定过程的基因， 分化 一个消减cDNA文库，富集了代表 与角膜-晶状体过程相关的基因活性 转分化，将被筛选。 由于基因是孤立的， 将在胚胎透镜形成过程中研究其表达， 并将进行具体的测试，以确定它们在这方面发挥的作用。 过程 这些基因的表达模式，沿着那些PI 已经获得，将用作组织移植中的标记物， 组织培养实验来检验特定组织 在胚胎发育过程中， 透镜感应。 最后，将进行实验，以确定是否 特异性生长因子在角膜培养物中引起透镜形成， 胚胎外胚层组织 越来越多的证据表明， 因子在胚胎细胞决定中起重要作用。

DESCRIPTION: Embryogenesis represents a complex process whereby a single cell, the fertilized egg, gives rise to the multicellular, adult organism. In vertebrate embryos specific tissue interactions, termed inductive interactions, play a major role in determining various cell fates. The general goal of this research is to understand the molecular and cellular basis of these processes. Vertebrate lens development has served as a model system in which to examine these events, since the development of this organ is triggered by a series of specific tissue interactions. The success of this system is due to its accessibility to direct experimental manipulation, particularly in amphibian embryos. While the PI has a firm understanding of the tissue interactions involved in vertebrate lens inductions, very little is known about the molecular basis for the process of lens cell determinination, or the signaling molecules involved in lens induction. These issues are the main focus of this research proposal. Continued effort will be devoted to identifying specific changes in gene expression which are associated with the processes of lens cell determination and differentiation using the from Xenopus laevis. In Xenopus, the larval cornea can undergo transdifferentiation to form a lens. Substantial evidence indicates that this process is related to that of embryonic lens development at both the molecular and cellular levels. The phenomenon of cornea-lens transdifferentiation represents a more convenient system with which to isolate genes involved in the processes of lens cell determination and differentiation. A subtracted cDNA library, enriched in clones representing gene activity associated with the process of cornea-lens transdifferentition, will be screened. As genes are isolated, their expression will be studied during the process of embryonic lens formation, and specific tests will be conducted to determine the role they play in this process. The expression patterns of these genes, along with those the PI has already obtained, will be used as markers in tissue transplantation and tissue culture experiments to examine the role that specific tissue interactions play in triggering changes in gene expression during embryonic lens induction. Finally, experiments will be performed to determine whether specific growth factors elicit lens formation in cultures of cornea and embryonic ectodermal tissues. There is mounting evidence that growth factors play important roles in embryonic cell determination.