CHARACTERIZATION OF LOCALIZED MATERNAL MRNA

胚胎决定在一定程度上是由形态发生介导的 卵子胞质中的特定物质。这个 一般的蛋的植物区，特别是蛙卵是 特别感兴趣，因为有两个已知的决定因素，它们规定了 生殖细胞谱系和诱导背轴发育的生殖细胞 构造，已知存在于该地区。最近的证据 表明mRNAs可以作为决定因素发挥作用。这 实验室发现，一小群mRNAs定位于 Xenoupus卵母细胞的营养极，并克隆了一个这样的 RNA(Veg2)。Veg2 RNA特别与 卵母细胞的细胞骨架。 在这项建议中，实验被概述为(1)确定何时 Veg2 RNA在非洲爪哇发育过程中表达，并 对其蛋白质产物进行表征；(2)研究其蛋白质产物的模式 VEG2RNA及其蛋白产物在正常和正常状态下的遗传 受扰胚胎发生；(3)建立 将Veg2 RNA正确定位于植物极点；(4)探索 VEG2RNA与卵母细胞减数的关系(5) 启动旨在测试发育功能的研究 (6)确定其他植物定位的mRNAs 与细胞骨架有关。 一般的策略包括在杂交中使用Veg2cdna克隆 和原位杂交程序，以跟踪其发育 细胞层面的命运。VEG2核糖核酸显微注射入脑内 正常和受干扰的蛋的动物极将产生信息 关于消息本地化的机制。抗体 将在表达载体中表达出的Veg2蛋白 系统，并用于表征Veg2蛋白的特性 生化性质及其在发育中的可能作用。

Embryonic determination is mediated in part by morphogenetic substances specifically localized in the cytoplasm of the egg. The vegetal region of eggs in general and frog eggs in particular is of special interest because two known determinants, those specifying the germ cell lineages and those inducing the dorsal axial structures, are known to reside in this region. Recent evidence suggests that mRNAs could function as determinants. This laboratory has found that a small group of mRNAs are localized to the vegetal pole of Xenoupus oocytes and has cloned one such RNA (Veg2). Veg2 RNA is specifically associated with the oocyte's cytoskeleton. In this proposal experiments are outlined to (1) determine when Veg2 RNA is expressed during Xenopus development and to characterize its protein product; (2) examine the pattern of inheritance of Veg2 RNA and its protein product during normal and perturbed embryogenesis; (3) establish the requirements for correct localization of Veg2 RNA to the vegetal pole; (4) explore the relationship of Veg2 RNA to the oocyte's cytoskeletion; (5) initiate studies designed to assay for the developmental function of Veg2 RNA; (6) determine if other vegetally localized mRNAs are associated with the cytoskeleton. The general strategy involves using the Veg2 cDNA clone in blot and in situ hybridization procedures to follow its developmental fate at the cellular level. Microinjection of Veg2 RNA into the animal pole of normal and perturbed eggs will yield information concerning the mechanisms of message localization. Antibodies will be raised to Veg2 protein produced in an expression vector system and used to characterize the Veg2 protin as to its biochemical nature and its possible function in development.