RUI: Use of Transgenic Xenopus Embryos to Study Cell Specification in Eye Development

眼睛发育中的细胞规格脊椎动物的眼睛是从前脑的两个区域的细胞发育而来的，这些细胞专门化(或分化)产生多种类型的细胞。这些细胞类型包括感光细胞(探测光线)、多种神经细胞(整合感光细胞的信号并将信号发送到大脑)和几种类型的支持细胞。大脑区域被指定为形成眼睛的机制，以及这些区域中的细胞被指定为形成不同类型的细胞的机制，还不是很清楚。这项拟议的研究将检验实验室中的一种模式生物--非洲爪蛙--的眼睛发育。发育中的眼睛内的细胞通过释放特定的信号蛋白进行交流；这些蛋白与其他细胞上的受体结合，影响细胞的决定。一组信号蛋白被称为FGFs，在眼睛发育的几个过程中使用。成纤维细胞生长因子可以结合并激活四种不同的成纤维细胞生长因子受体(FGFRs)中的任何一种，但目前尚不清楚特定FGFRs的激活是否会影响眼内细胞的分化。将进行实验，以验证不同FGFRs激活导致眼细胞以不同方式分化的假设。抑制性FGFRs将在发育中的眼睛中表达；然后就可以比较通过例如FGFR-1阻断信号的效果与阻断其他FGFRs的效果。这项分析将显示不同的FGFR是否在眼睛发育中发挥不同的作用。这些实验将利用最近开发的青蛙转基因技术，这使得将特定基因引入青蛙胚胎成为可能。引入的基因将包括引导基因仅在眼睛中表达的DNA，以及编码抑制性FGFR的DNA。。这些研究将有助于更好地了解脊椎动物眼睛发育的机制，以及当眼睛发育异常时，哪些过程可能会被扰乱。最后，比较不同生物的眼睛发育将有助于更好地理解眼睛是如何进化的。本科生将强烈参与这项拟议的研究。因此，这项研究将在一定程度上服务于培养下一代科学家。

Cell specification in eye developmentEyes in vertebrates develop from cells in two regions of the forebrain, and these cells specialize (or differentiate) to generate many cell types. The cell types include photoreceptor cells (which detect light), many types of neural cells (which integrate signals from photoreceptor cells and send signals to the brain), and several types of supporting cells. The mechanisms by which regions of the brain become specified to form eyes, and cells in these region become specified to form different cell types, are not well understood. The proposed research will examine eye development in a model laboratory organism, the frog Xenopus laevis. Cells within the developing eyes communicate by releasing specific signaling proteins; these proteins bind to receptors on other cells, influencing cell determination. One group of signaling proteins, called FGFs, is used in several processes during eye development. FGFs can bind to, and activate, any of four different FGF receptors (FGFRs), but it is not clear whether activation of specific FGFRs affects cell differentiation in the eye.Experiments will be conducted to test the hypothesis that activation of different FGFRs causes eye cells to differentiate in different ways. Inhibitory FGFRs will be expressed in the developing eye; it will then be possible to compare the effects of blocking signaling through, say, FGFR-1 with the effects of blocking other FGFRs. This analysis will show whether different FGFRs play distinct roles in eye development. The experiments will utilize recently developed transgenic technology in frogs, which makes it possible to introduce specific genes into frog embryos. The introduced genes will consist of DNA that directs the gene to be expressed only in the eye, coupled to DNA encoding an inhibitory FGFR. . These studies will lead to a better understanding of the mechanisms by which vertebrate eyes develop, and which processes may be disrupted when eyes develop abnormally. Finally, comparison of eye development in different organisms will contribute to a better understanding of how eyes have evolved.Undergraduate students will be strongly involved in the proposed research. This research will thus serve, in part, to train the next generation of scientists.