GENETIC EXPRESSION/DEVELOPMENT/CONTROL/MRNA UTILIZATION

这项研究的目的是为了进一步了解 发育和分化的分子机制。这个 基本主题将是对早期操作的手段的说明 胚胎发生，用于调节遗传信息的使用。海胆 将被用作模型胚胎系统。蛋白质合成的模板 存在于未受精卵中的主要位于纹状体后 核糖核蛋白复合体被称为游离mRNP或信息体，以及一个大的 发育中的胚胎合成的部分信使核糖核酸进入游离RNP 游泳池。由于它们的蜂窝位置，似乎翻译 这些模板中的大多数都是在细胞质中控制的。我们将系统地 定性和定量表征特定种类的mRNA 为了更好地理解FREE的功能，在FREE中存在RNP RNPs及其包含的遗传信息的表达方式 控制住了。我们的主要方法将是比较 游离RNP信使核糖核酸主动参与蛋白质合成，即 存在于多倍体中。重组表达序列DNA文库的构建 对应于低复杂性-高丰度类的海胆 将采用在大肠杆菌中克隆的Poly(A)+mRNA。我们将从以下选项中选择 这个文库有许多有趣的克隆序列可供分析。 这一选择包括适当的DNA-RNA杂交分析和 混合-逮捕-翻译实验。从胚胎中分离出的mRNA 发展的不同阶段，将以下列方面为特点： 浓度、细胞位置(多聚体/游离RNP分布)、 开发中的合成、合成速率、周转动力学(半衰期)、 以及在体外翻译的效率。从这些数据来看， 有可能获得有关新陈代谢的大量信息 一些特定信使RNA在快速发展中的利用 系统，从而平移控制机制运行的性质 处于早期开发阶段。

The objective of this research is to gain further understanding of the molecular mechanisms underlying development and differentiation. The fundamental theme will be the elucidation of the means operating in early embryogenesis for regulating the use of genetic information. Sea urchins will be used as a model embryonic system. Templates for protein synthesis present in the unfertilized egg are located primarily in postribosomal ribonucleoprotein complexes called free mRNP or informosomes, and a large portion of the mRNA synthesized by developing embryos enters the free RNP pool. Because of their cellular location it appears that the translation of these templates is controlled in the cytoplasm. We will systematically characterize both qualitatively and quantitatively specific species of mRNA present in the free RNPs in order to better understand the function of free RNPs and how the expression of the genetic information they contain is controlled. Our main approach will be to compare various properties of the free RNP mRNA to the mRNA actively engaged in protein synthesis, which is present in polysomes. A recombinant DNA library of expressed sequences corresponding to the low complexity-high abundance class of sea urchin poly(A) plus mRNA cloned in E.coli will be employed. We will select from this cDNA library a number of interesting cloned sequences for analysis. This selection involves appropriate DNA-RNA hybridization analyses and hybrid-arrest-translation experiments. The mRNAS isolated from embryos at various stages of development, will be characterized in terms of: concentration, cellular location (polysomes/free RNP distribution), time of synthesis in development, rate of synthesis, turnover kinetics (half-life), and efficiency to be translated in vitro. From these data it will be possible to gain considerable information concerning the metabolism and utilization of a number of specific messenger RNAs in a rapidly developing system and thereby the nature of translational control mechanisms operating in early development.