ANALYSIS OF CONTROL GENE ACTION IN VOLVOX DEVELOPMENT

控制基因在 VOLVOX 发育中的作用分析

• 批准号: 3274611
• 负责人: DAVID L KIRK
• 金额: $ 25.55万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1980
• 资助国家: 美国
• 起止时间: 1980-01-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3274611
• 关键词: Dinoflagellates; biochemical evolution; cell differentiation; cell growth regulation; cell transformation; cell type; developmental genetics; electrofocusing; eukaryote; gel electrophoresis; gene expression; genetic manipulation; genetic mapping; genetic markers; genetic recombination; genetic regulation; genetic transcription; genome; ion exchange chromatography; messenger RNA; molecular cloning; molecular genetics; nonmammalian vertebrate embryology; nucleic acid sequence; prokaryote; protein biosynthesis; radionuclide double label; restraint; temperature sensitive mutant

The primary long-term goal of this research is to elucidate how differentiation of two distinct cell types may be programmed in the genome of a multicellular organism, using as a model Volvox carteri, which exhibits complete division of labor between mortal somatic cells and immortal germ cells. The secondary long-term goal is to use Volvox and its close unicellular and colonial relatives to study the molecular genetic basis for the evolution of such a germ/soma dichotomy. The following specific studies are proposed: 1. Detailed molecular analysis of the regA gene, to gain insight into how this central important gene acts to preclude somatic cells from redifferentiating as reproductive cells. Steps include cloning of the gene, analysis of the sequence organization of the gene in somatic and reproductive cells (in order to test the hypothesis that expression of the gene is regulated by DNA rearrangement), and analysis of patterns of regA transcription, and translation and cellular distribution of its protein product. 2. Development of a transformation system that could be used initially to test the function of putative regA clones, and later to study other genes of developmental interest. Steps include testing of four different DNA-delivery methods with a variety of vectors bearing prokaryotic selectable markers, and development of vectors with homologous selectable markers. 3. Analysis of genes regulating other steps in development of the germ/soma dichotomy, including saturation mapping of such genes, screens for revertants and/or second-site suppressors nd physical mapping of the genes by use of restriction fragment length polymorphisms 4. Study of the phylogeny and stage-specific and/or cell-type-specific patterns of expression of several families of "V/C" genes which are transcribed in Volvox, but have few if any homologues in the genome of the related unicellular organism, Chlamydomonas. The health-relatedness of this research derives from the analogy that it is possible to draw between somatic ell redifferentiation in regA mutants of Volvox and neoplasia in humans. In regA mutants, somatic cells (which are normally terminally differentiated and post-mitotic) redifferentiate and proliferate without restraint. It is possible that understanding how regA functions in wild type Volvox to prevent such restrained proliferation might provide novel insights that could be drawn upon in exploring growth control in higher eukaryotes.

这项研究的主要长期目标是阐明如何 可以在 多细胞生物的基因组，用作模型volvox 卡特里（Carteri），在凡人之间表现出完整的劳动力 体细胞和不朽生殖细胞。 长期的次要 目标是使用沃尔沃克斯及其近距离细胞和殖民地 亲戚研究进化的分子遗传基础 这种细菌/索马二分法。 以下具体研究是 提出：1。详细的Rega基因的分子分析到 深入了解该中心重要基因如何排除该基因 从重新分化为生殖细胞的体细胞。 步骤 包括基因的克隆，序列组织的分析 体细胞和生殖细胞中的基因（为了测试 基因表达受DNA调节的假设 重新安排）和Rega转录模式的分析，以及 其蛋白质产物的翻译和细胞分布。 2。 开发最初可以使用的转换系统 测试推定的Rega克隆的功能，然后研究 其他发育兴趣的基因。 步骤包括测试 具有多种向量的四种不同的DNA递送方法 轴承可选标记和向量的发展 带有同源可选标记。 3。基因分析 调节细菌/索马二分法发展的其他步骤， 包括此类基因的饱和映射，归还物的筛选 和/或第二位抑制器和/或通过 限制片段长度多态性的使用4。 系统发育和阶段特异性和/或细胞类型的特异性模式 转录的几个“ v/c”基因家族的表达 在Volvox中，但在基因组中几乎没有任何同源物 相关的单细胞生物，衣原体。 这项研究的健康相关性来自类比 可以在体细胞重新分化之间绘制 在人类的沃尔沃克斯和肿瘤的雷加突变体中。 在雷加 突变体，体细胞（通常是终端的 差异化和有丝分裂后）重新分化和增殖 没有约束。 有可能了解雷加 野生型沃尔沃克斯的功能以防止这种受限 扩散可能会提供可以吸引的新颖见解 在探索较高真核生物的生长控制方面。