GENE REGULATION IN EMBRYOGENESIS

研究了几个基因的调控， 在海胆的胚胎发生中起作用，基于它们的生产 RNA在早期发育中的峰值数量，以及基于 RNA的后期积累。 其中两个基因产生 不同的RNA形式在早期和晚期阶段：一个基因之间切换 多态形式，在早期阶段产生单个poly（A）+ mRNA， 在晚期有两种不同大小的poly（A）- mRNA。 另 在单个早期poly（A）+和晚期poly（A）-mRNA之间转换。 动物化剂倾向于增加和延长早期代谢产物的合成。 功能mRNA和延迟晚期功能mRNA合成的开始。 植物化剂倾向于增强晚期功能mRNA的合成。 两个mRNA 还诱导出满足早期功能标准的物种 通过用动物化处理晚期胚胎来合成 硫酸锌。 这些诱导的mRNA之一是聚（A）+形式的 一组多态性mRNA，如上所述。 感应反转了 正常的发展变化。 为了理解这些机制 通过这些发展变化的影响， 与胚胎发生的决定性事件的关系，我们将分析 这些不同基因的结构，特别是分配起源的基因， 多态性的mRNA，并研究转录，加工和稳定性 各种RNA的，以及它们作为模板的性质， 翻译，解释不同大小的功能意义 和多聚腺苷酸化的状态。 将利用感应现象 作为一种实验性控制基因活动的方法。 目前两 已知有几种mRNA富集在pluteus的外胚层组织中 中胚层-内胚层组织中有1种。 我们将研究 与mRNA相比，核RNA的发育增强似乎 参与建立这些mRNA的组织特异性。 变化 在所有这些与失衡相关的mRNA的浓度中， 在这三种生殖组织的发育中， 植物化胚胎，可能是理解促进 细胞分化的差异基因活性。 这些过程 可以决定正常与异常细胞的过程 分化

Studies are proposed on the regulation of several genes with posited early functions in the embryogenesis of the sea urchin, based on their production of peak amounts of RNA in early development, and late functions based on the late stage accumulation of their RNAs. Two of these genes produce different RNA forms in early and late stages: One gene switches between polymorphic forms, producing a single poly(A)+ mRNA in the early stages and two different sizes of poly(A)- mRNA in the late stages. The other switches between single early poly(A)+ and late poly(A)- mRNAs. Animalizing agents tend to increase and prolong the syntheses of early function mRNAs and delay the onset of late function mRNA synthesis. Vegetalizing agents tend to enhance late function mRNA synthesis. Two mRNA species fulfilling the criterion of early stage function are also induced to be synthesized by treatment of late stage embryos with the animalizing agent zinc sulfate. One of these induced mRNAs is the poly(A)+ form of the set of polymorphic mRNAs, described above. The induction reverses the normal developmental program of changes. To understand the mechanisms through which these developmental changes are effected and their relationship to the determinative events of embryogenesis, we shall analyze the structures of these various genes, especially to assign origins to the polymorphic mRNAs, and to study the transcription, processing and stability of the various RNAs, as well as their properties as templates for translation, to explain the functional significance of the different sizes and states of polyadenylation. The induction phenomenon will be utilized as a way of experimentally controlling gene activity. At present, two species of mRNA are known to be enriched in ectoderm tissue of the pluteus and one species in the mesoderm-endoderm tissue. We shall study the developmental enhancement of nuclear RNA compared to mRNA that appears to be involved in establishing the tissue specificity of these mRNAs. Shifts in the concentrations of all of these mRNAs in association with imbalances in the development of the three germ tissues, studied in animalized and vegetalized embryos, may be a basis for understanding the promotion of cellular differentiation by differential gene activity. These processes may pivotally decide the course of normal vs. abnormal cellular differentiation.