MOLECULAR AND CELLULAR BASIS OF LENS DEVELOPMENT

描述：胚胎发生是一个复杂的过程，单个 细胞，即受精卵，产生了多细胞的成年有机体。 脊椎动物胚胎中特定的组织相互作用，称为诱导性 相互作用，在决定各种细胞命运方面发挥着重要作用。这个 这项研究的总体目标是了解分子和细胞 这些过程的基础。脊椎动物晶状体的发展已经成为一个典范 检查这些事件的系统，因为这个器官的发展 是由一系列特定的组织相互作用触发的。的成功之处 这个系统是因为它可以直接进行实验操作， 尤其是在两栖类胚胎中。虽然私家侦探对 脊椎动物晶状体诱导中涉及的组织相互作用很少 已知晶状体细胞过程的分子基础 决定，或参与晶状体诱导的信号分子。 这些问题是本研究方案的主要着力点。持续努力 将致力于识别基因表达的特定变化，这些变化 与晶状体细胞的决定和分化过程有关 使用非洲爪哇的非洲爪哇。在非洲爪哇，幼虫的角膜可以经历 转分化形成晶状体。确凿的证据表明 这一过程与胚胎晶状体的发育过程有关 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，通过它可以 分离参与晶状体细胞测定过程的基因和 差异化。一个消减的cDNA文库，富含代表 与角膜晶状体发育过程相关的基因活性 转分化，将被筛选出来。随着基因的分离，他们的基因 将研究胚胎晶状体形成过程中的表达， 并将进行具体测试，以确定它们在这一过程中所扮演的角色 进程。这些基因的表达模式，以及那些PI 已经获得，将被用作组织移植和 组织培养实验检测特定组织的作用 相互作用在胚胎期间触发基因表达变化中的作用 透镜诱导法。最后，将进行实验以确定是否 特异性生长因子诱导培养的角膜和晶状体形成 胚胎外胚层组织。越来越多的证据表明，经济增长 在胚胎细胞测定中，各种因素起着重要作用。

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.