MESSENGER RNA DISTRIBUTION IN SEA URCHIN EMBRYOS

这项拟议的研究的目的是确定 单个基因在海胆不同细胞系中的表达 紫球藻(Stronglocolotus PurPuratus)胚胎。原位杂交技术 将被用来确定单个RNA的空间分布， 使用来自重组DNA的放射性标记RNA探针 包含单独的海胆基因序列。使用探测器表示 在囊胚期表达的mRNAs，个体限制的程度 将检查发育过程中一个或多个细胞系的mRNA，以及 不同谱系中特定的mRNA组出现的时间将是 分析过了。细胞谱系特异的mRNAs将被用作构建 在mRNA表达水平上的胚胎命运图。组织 3个多基因家族不同成员表达的特异性 将会被调查。将为6个肌动蛋白建立详细的模式 初步研究表明，基因在一种高度 世系特定和阶段特定的方式。在表达式中切换的时间 组蛋白基因从早期到晚期的变异将在不同的 细胞谱系。此交换机与其他交换机之间的可能关联 发育事件(特定细胞类型的mRNAs的表达，变化 细胞分裂速率)将被检测。不同类型的分布 将比较H_2B亚类的晚期变异组蛋白mRNAs。空间 α和β微管蛋白mRNAs的表达模式将是 调查过了。细胞系特异的mRNAs出现的时间将 与差异化事件有关。不同因素之间的相互关系 通过表达特定的mRNA集进行分化的途径将是 使用改变确定/区分的程序进行检查 细胞谱系。这些研究是理解 早期发育对差异基因表达的要求。

The aim of the proposed research is to determine the specificity of expression of individual genes in various cell lineages of the sea urchin (Stronglylocentrotus purpuratus) embryo. In situ hybridization techniques will be used to detemine the spatial distribution of individual mRNAs, using radioactively labeled RNA probes derived from recombinant DNAs containing individual sea urchin mRNA sequences. Using probes representing mRNAs expressed at blastula stage, the extent of restriction of individual mRNAs to one or more cell lineages during development will be examined, and the time of appearance of specific mRNA sets in different lineages will be analyzed. Cell-lineage-specific mRNAs will be used as markers to construct a fate map of the embryo at the level of mRNA expression. The tissue specificity of expression of different members of 3 multi-gene families will be investigated. Detaled patterns will be established for 6 actin genes which preliminary studies have shown are expressed in a highly lineage- and stage-specific manner. The timing of the switch in expression of histone genes from early to late variants will be compared in different cell lineages. Possible correlations between this switch and other developmental events (expression of cell-type-specific mRNAs, changes in rate of cell division) will be examined. The distributions of different late-variant histone mRNAs of the H2B subclass will be compared. Spatial patterns of expression of Alpha and Beta tubulin mRNAs will be investigated. The timing of appearance of cell-lineage-specific mRNAs will be related to events of differentiation. The correlation of different pathways of differentiation with expression of specific mRNA sets will be examined using procedures which alter the determination/differentiation of cell lineages. These studies are fundamental to understanding the requirements for differential gene expression during early development.