ASYMMETRY AND CELL INTERACTIONS IN EMBRYOS

胚胎中的不对称性和细胞相互作用

• 批准号: 2201800
• 负责人: WILLIAM B WOOD
• 金额: $ 12.96万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-01 至 1997-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2201800
• 关键词: Caenorhabditis elegans; cell cell interaction; cell differentiation; cellular polarity; early embryonic stage; electron microscopy; embryo /fetus tissue /cell culture; fusion gene; gene expression; gene mutation; genetic library; high voltage electron microscopy; lasers; micromanipulator; molecular cloning; phenotype; polymerase chain reaction; protein structure function

Recent evidence indicates that cell interactions play a more extensive role than previously realized in early embryogenesis of the nematode C elegans, and that these interactions differ on the left and right sides of the embryo. Using these findings as a starting point, this project will investigate the genetic control of embryonic left-right asymmetry (handedness), the relative importance of cell-autonomous determinants vs. inductive events in determining the developmental fates of cells in the early embryo and their behavior during gastrulation, and the mechanisms of both cell-autonomous and inductive modes of determination. A combined genetic and molecular approach will be taken, including characterization and eventual cloning and analysis of mutationally defined genes, as well as cloning of genes directly as lineage-specific cDNA's followed by isolation of mutations in these genes to study their functions. Specifically, the following kinds of experiments will be undertaken. Mutations that cause reversal of embryonic handedness will be analyzed to define and characterize the genes and gene products involved in handedness choice. Cell contacts during early embryogenesis will be mapped by microscopy to define likely points of intercellular communication. Blastomere isolation and recombination experiments in culture as well as laser ablation experiments with whole embryos will be carried out to determine which of a set of lineage-specific differentiation markers are expressed cell-autonomously and which require specific cell-cell interactions. Mutations that cause defects in early inductive events and onset of gastrulation will be identified and analyzed, phenotypically in chimeric embryos to determine which specific cells they affect, as well as genetically to define the genes and gene products that control these processes. The polymerase chain reaction will be exploited to make blastomere-specific cDNA libraries from small numbers of dissected cells, which can be used in subtraction experiments to isolate cloned genes whose expression is specific to certain embryonic lineages. One of several possible "reverse genetic" methods will be used to obtain mutations in these genes for phenotypic analysis. Information on control of embryonic handedness could help to understand the causes of human situs inversus, which often is accompanied by heart defects and other malformations. Mechanisms of cell fate determination by either cell-autonomous determinants or cell interactions are clearly relevant to problems posed by cancer and inherited developmental disorders.

最近的证据表明，细胞相互作用的效果更广泛 在线虫C的早期胚胎发生中的作用比以前实现的作用 秀丽隐杆线，这些相互作用在左侧和右侧有所不同 胚胎。 将这些发现作为起点，该项目 将研究胚胎左右不对称的遗传控制 （惯用性），细胞自主决定因素VS的相对重要性。 确定细胞中细胞发育命运的诱导事件 早期胚胎及其在胃肠道中的行为及其机制 细胞自主和电感的测定模式。 一个组合 将采取遗传和分子方法，包括表征 以及最终对突变定义基因的克隆和分析 作为基因的克隆直接为谱系特异性cDNA，然后是 这些基因中突变的分离以研究其功能。 具体而言，将进行以下类型的实验。 引起胚胎义逆转的突变将分析为 定义和表征涉及的基因和基因产物 撇态的选择。 早期胚胎发生过程中的细胞接触将是 通过显微镜映射以定义细胞间的可能点 沟通。 胚胎分离和重组实验 培养以及整个胚胎的激光消融实验将是 进行以确定哪一组特定的谱系 分化标记物以细胞自动表达，并且需要 特定的细胞 - 细胞相互作用。 早期导致缺陷的突变 将确定归纳事件和胃结构的发作，并 在嵌合胚胎中分析，表型，以确定哪种特定 它们影响的细胞以及遗传学以定义基因和基因 控制这些过程的产品。 聚合酶链反应 将利用从小 解剖细胞的数量，可用于减法实验 分离出特定于某些胚胎的表达的克隆基因 血统。 将使用几种可能的“反向遗传”方法之一 在这些基因中获得突变进行表型分析。 有关控制胚胎义的信息可能有助于理解 人类现场逆的原因，通常伴随着心脏 缺陷和其他畸形。 细胞命运确定的机制 通过细胞自主的决定因素或细胞相互作用是明显的 与癌症和遗传发展的问题有关 疾病。