PROTEIN/NUCLEIC ACID INTERACTIONS IN VERTEBRATE EMBRYOGENESIS

本项目的总体目标是确定和研究 调节脊椎动物胚胎发育的因子。 这项工作正在 以三种方式接近。 一种方法是分析法规， Dlx 3是果蝇基因的脊椎动物同源物之一， 在果蝇中，该基因调节肢体和感觉附属物 阵 青蛙和小鼠同源物都在表皮中表达， 鳃弓，在四肢的梯度。 老鼠的基因也是 活跃于毛囊、牙齿原基和其他部位。 DNA 元件和蛋白质-DNA相互作用负责这种表达 模式正在映射。 此外，靶向灭活和 错误表达研究被用来测试Dlx 3的功能， 转基因小鼠胚胎表皮中的基因表达。 采用的第二种方法是鉴定编码 Eph相关的受体酪氨酸激酶在特定的 早期青蛙胚胎的组织。 其中一种叫做Pagliaccio的激酶， 当在细胞中组成性激活时， 非洲爪蟾胚胎外胚层，可能通过调节钙粘蛋白功能。 一个相关的基因TCK也正在研究中。 第三种方法侧重于发展功能， 斑马鱼神经管中的钙依赖性细胞粘附分子。 一个新的钙粘蛋白，VN-cad，已被克隆，测序，并确定其特征 通过原位杂交。 正在进行功能研究， 将VN-cad信使RNA注射到斑马鱼胚胎中。

The general aim of this project is to identify and study the function of factors that regulate vertebrate embryonic development. This is being approached in three ways. One approach is to analyze the regulation and function of Dlx3, one of the vertebrate homologs of the Drosophila gene Distal-less. In flies this gene regulates limb and sensory appendage formation. The frog and mouse homologs are both expressed in epidermis, branchial arches, and in gradients in the limbs. The mouse gene is also active in hair follicles, tooth primordia and other locations. DNA elements and protein-DNA interactions responsible for this expression pattern are being mapped. In addition, targeted inactivation and mis-expression studies are being used to test for the function of Dlx3 gene expression in the epidermis of transgenic mouse embryos. A second approach employed has been to identify mRNAs encoding Eph-related receptor tyrosine kinases that are expressed in specific tissues of early frog embryos. One such kinase, called Pagliaccio, has been shown to affect cell-cell adhesion when constitutively activated in Xenopus embryonic ectoderm, probably by modulating cadherin function. A related gene, TCK, is also being studied. The third approach focuses on the developmental function of calcium-dependent cell adhesion molecules in the zebrafish neural tube. A novel cadherin, VN-cad, has been cloned, sequenced, and characterized by in situ hybridization. Functional studies are being carried out by injection of VN-cad messenger RNA into zebrafish embryos.