MOLECULAR AND CELLULAR BASIS OF LENS DEVELOPMENT

胚胎发生是一个复杂的过程，受精卵通过这个过程产生 多细胞成体。在脊椎动物胚胎中，诱导相互作用 在决定细胞命运的过程中，特定组织之间起着重要作用。这个 脊椎动物的晶状体提供了一个合适的模型系统来定义分子 决定细胞命运的机制，因为发育是由 一系列特定的组织相互作用。晶状体分化涉及几个 阶段：能力、规范和决心。非洲爪哇代表非洲爪哇 一个方便的、可操作的系统，用于研究晶状体的发育，因为 这些阶段是在时间上定义的，特定的组织也是如此 所需的交互。在非洲爪哇，幼虫的角膜可以经历 转分化为晶状体。这一过程可以说反映了自然的 晶状体的测定和分化事件。这代表着一种方便的 从中分离涉及转分化的基因的系统， 理论上处于胚胎晶状体形成的各个阶段。少年派有 创建了一个消减的cdna文库，该消减文库富含特定于 转分化。该文库将对潜在的基因进行筛选 参与转分化和晶状体诱导，并评估候选人 通过表达研究和功能测试，它们在这些过程中的作用。这个 其中一些基因的表达模式将被用来测试 组织移植实验中的晶状体诱导。最后，实验将 以确定在培养中诱导晶状体形成的生长因素 角膜和胚胎外胚层组织。怀疑这两个因素都在发挥作用 根据现有证据和从视网膜分离出的新因素 将对文库进行测试。

Embryogeneis is a complex process whereby the fertilized egg gives rise to a multicellular adult organism. In vertebrate embryos, inductive interactions between specific tissues play a major role in determining cell fate. The vertebrate lens provides an appropriate model system to define the molecular mechanism involved in determining cell fate because development is triggered by a series of specific tissue interactions. Lens differentiation involves several stages: competence, specification and determination. Xenopus laevis represents a convenient, manipulatable system in which to study lens development because these stages have been temporally defined, as have the specific tissue interactions that are required. In Xenopus, the larval cornea can undergo transdifferentiation into lens. This process arguably reflects the natural events in lens determination and differentiation. This represents a convenient system from which to isolate genes involved in transdifferentiation and, theoretically in the various stages of embryonic lens formation. The PI has created a subtracted cDNA library enriched for genes that are specific to transdifferentiation. The library will be screened for genes potentially involved in transdifferentiation and lens induction and candidates assessed for their roles in these processes by expression studies and functional tests. The expression patterns of a number of these genes will be used to test models of lens induction in tissue transplantation experiments. Finally, experiments will be performed to identify growth factors that elicit lens formation in cultures of cornea and embryonic ectoderm tissue. Both factors suspected to play a role based on existing evidence and newly identified factors isolated from a retinal cDNA library will be tested.