BIOCHEMICAL AND GENETIC ANALYSES OF AN EMBRYONIC ANTIGEN

这项提议的目标是分离和鉴定一种哺乳动物 胚胎细胞表面糖蛋白(ESGp)的表达和生化 结构似乎是受发育调节的。来自两个小区的ESGp 通过桑拿期，小鼠胚胎以单个离散的方式迁移 分子量为90 kDa的电泳带。在囊胚期 然而，在这一阶段，分子以一条宽广的、异质带的形式迁移。 从90 kDa到110 kDa不等。使用畸胎癌细胞类似物，我有 表明这条带实际上是由三个不同的分子组成的 兆瓦90，95和110 kDa，每一个都是由 胚泡的不同细胞类型：胚胎外胚层(EE)和 内脏(VE)和壁层内胚层(PE)。对……的调查 不同的小鼠组织和细胞系只揭示了这三种形式的 糖蛋白。所有未分化的细胞和精子都表达90 kDa 胚性外胚层的“胚性”形态特征，分化为 细胞和成体组织表达110 kDa的“成体”形式 顶叶内胚层；仅显示胚胎内脏内胚层细胞。 表达95 kDa的形式。为了更好地理解 小鼠胚胎发育中的这些分子差异，我建议 分离胚胎和成体ESGps并分析其蛋白质和 碳水化合物的部分。将会产生抗血清来对抗隔离的 糖蛋白，并用于检测细胞的功能和分布 胚胎、组织和细胞系中的ESGp。抗体也将被用于 筛选ESGp阳性克隆的cDNA文库。这段cDNA会是 测序和ESGp序列将在它们之间进行比较，并 与所有其他已知序列进行同源性比较。这些研究将 当然可以加强我们目前对生物化学和 控制哺乳动物早期发育的遗传相互作用。

The goals of this proposal are to isolate and characterize a mammalian embryonic cell surface glycoprotein (ESGp) whose expression and biochemical structure appear to be developmentally regulated. ESGp from two cell through morula stage mouse embryos migrates as a single discrete electrophoretic band at a molecular weight of 90 kDa. At the blastocyst stage, however, the molecule migrates as a broad, heterogeneous band ranging from 90 to 110 kDa. Using teratocarcinoma cell analogues, I have shown that this band is actually a composite of three distinct molecules of MW 90, 95, and 110 kDa each of which is synthesized uniquely by the different cell types of the blastocyst: the embryonic ectoderm (EE) and visceral (VE) and parietal endoderms (PE), respectively. A survey of various mouse tissues and cell lines reveal only these three forms of glycoprotein. All undifferentiated cells and sperm express the 90 kDa "embryonic" form characteristic of embryonic ectoderm, which differentiated cells and adult tissues express the 110 kDa "adult" form characteristic of parietal endoderm; only embryonic visceral endoderm cells have been shown to express the 95 kDa form. In order to understand the significance of these molecular differences in mouse embryonic development, I propose to isolate the embryonic and adult ESGps and to analyze their protein and carbohydrate moieties. Antisera will be raised against the isolated glycoproteins and used to examine both the function and distribution of the ESGp in embryos, tissues and cell lines. The antibodies will also be used to screen cDNA libraries for ESGp positive clones. This cDNA will be sequenced and the ESGp sequences will be compared amongst themselves and with all other known sequences for possible homology. These studies will certainly enhance our current understanding of both the biochemical and genetic interactions regulating early mammalian development.