Patterning of the optic vesicle by extrinsic factors

描述（由申请人提供）：本项目的长期目标是 了解细胞和组织间的相互作用如何调节 中枢神经系统 组织-组织相互作用的破坏可导致 影响大脑和眼睛的各种严重出生缺陷，如 前脑无裂畸形、先天性无眼畸形、小眼畸形和无脑畸形。 了解正常的开发过程将允许更好地 这些缺陷的预防和处理。 建议研究以下方面的作用： 参与这些相互作用的信号分子使用胚胎眼睛， 一个前脑发育的模型系统，其中相同的机制大多数 可能会规范区域规范。 经典的胚胎学研究 表明眼外组织是正常眼睛生长所必需的， 分化 目前关于这些信号的信息还很少 参与这些互动。 在视泡的外植体培养中， 鸡胚，去除眼外间充质严重干扰 视网膜色素上皮（RPE）的形成。 TGF β家族 成员激活素已被证明是一个候选信号，它完全模仿了 眼外间充质对体外培养的RPE发育的影响。 建议测试激活素信号通路是否是 鸡胚眼RPE形成所需的蛋白质（Aim 1）。 干涉 与发育中的RPE中的激活素信号通路，可溶性激活素类型 II受体将被应用以及拮抗剂的异位表达。 Smads（Smad 6，7）和截短的激活素II型受体， 电穿孔 将确定激活素或相关信号是否被激活。 由眼外间充质产生（Aim 2）。 由于颅间质 含有RPE发育的诱导物，足够量的这种组织可以 分离用于简并PCR策略。 随后，经鉴定 分子将被克隆并在外植体中测试RPE促进活性 培养和转染鸡胚。

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand how cellular and tissue-tissue interactions regulate development of the central nervous system. Disruption of tissue-tissue interactions can lead to a wide range of serious birth defects affecting the brain and eye, such as holoprosencephaly, congenital anophthalmia, microphthalmia, and anencephaly. Understanding the normal process of development will allow for better prevention and treatment of such defects. It is proposed to study the role of signaling molecules involved in these interactions using the embryonic eye as a model system for forebrain development, where the same mechanisms most likely regulate regional specification. Classical embryological studies have shown that the extraocular tissues are required for normal eye growth and differentiation. At present there is little information about the signals involved in these interactions. In explant cultures of optic vesicles from chick embryos, removal of the extraocular mesenchyme severely interferes with the formation of the retinal pigmented epithelium (RPE). The TGFbeta family member activin has been shown to be a candidate signal that exactly mimics the effects of the extraocular mesenchyme on RPE development in vitro. It is proposed to test the hypothesis whether the activin signaling pathway is required for RPE formation in the chick embryonic eye (Aim 1). To interfere with the activin signaling pathway in the developing RPE, soluble activin type II receptors will be applied as well as ectopic expression of antagonistic Smads (Smad6, 7) and truncated activin type II receptors using electroporation. It will be determined whether activin or a related signal is produced by the extraocular mesenchyme (Aim 2). Since cranial mesenchyme contains the inducer of RPE development, sufficient amounts of this tissue can be isolated for a degenerate PCR strategy. Subsequently, the identified molecule will be cloned and tested for the RPE-promoting activity in explant cultures and by transfection of chick embryos.