GENETIC EXPRESSION/DEVELOPMENT/CONTROL/MRNA UTILIZATION

本研究的目的是进一步了解 发育和分化的分子机制。 的 基本主题将是阐明手段运作的早期 胚胎发生调控遗传信息的使用。 海胆 将被用作胚胎系统的模型。 蛋白质合成模板 存在于未受精卵中的主要位于postribosomal 核糖核蛋白复合物，称为游离mRNP或信息体，和一个大的 由发育中的胚胎合成的mRNA的一部分进入游离RNP 池 由于它们的细胞位置， 在细胞质中受到控制。 我们将系统地 定性和定量表征mRNA的特定种类 为了更好地理解免费RNP的功能， RNP以及它们所包含的遗传信息的表达是如何 控制。 我们的主要方法是比较 游离RNP mRNA到积极参与蛋白质合成的mRNA， 存在于多聚核糖体中。 表达序列的重组DNA文库 对应于低复杂度高丰度的海胆类 将使用在大肠杆菌中克隆的poly（A）加mRNA。 我们将从 该cDNA文库包含许多感兴趣的克隆序列用于分析。 这种选择涉及适当的DNA-RNA杂交分析， 杂交抑制翻译实验。 从胚胎中分离的mRNAS在 不同发展阶段的特点是： 浓度、细胞位置（多聚核糖体/游离RNP分布）、 开发中的合成、合成速率、转换动力学（半衰期）， 和体外翻译效率。 根据这些数据， 可以获得有关代谢的大量信息， 利用一些特定的信使RNA在快速发展的 系统，从而平移控制机构操作的性质 在早期发展中。

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.