MESSENGER RNA DISTRIBUTION IN SEA URCHIN EMBRYOS

这项研究的目的是确定 单个基因在海胆不同细胞系中的表达 （Stronglylocentrotus purpuratus）胚。 原位杂交技术 将用于确定单个mRNA的空间分布， 使用来自重组DNA的放射性标记的RNA探针 含有单个海胆mRNA序列。 使用探测器代表 在囊胚期表达的mRNA，个体的限制程度， 将检查发育过程中一种或多种细胞谱系的mRNA， 不同谱系中特定mRNA组出现的时间将是 分析了 细胞谱系特异性mRNA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 将被调查。 将为6个动作建立详细模式 初步研究表明，这些基因在高表达的 谱系和特定阶段的方式。 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 此开关与其他开关之间的可能相关性 发育事件（细胞类型特异性mRNA的表达， 细胞分裂率）进行检测。 不同的分布 将比较H2 B亚类的晚期变体组蛋白mRNA。 空间 α和β微管蛋白mRNA的表达模式将是 研究了 细胞谱系特异性mRNA出现的时间将 与分化事件有关。 不同的相关性 表达特定mRNA组的分化途径将是 使用改变确定/区分的程序进行检查 细胞谱系 这些研究对于理解 在早期发育过程中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.