EGG CYTOPLASMIC INFORMATION IN CELL DIFFERENTIATION

细胞分化中的卵细胞质信息

• 批准号: 3320978
• 负责人: J RICHARD WHITTAKER
• 金额: $ 21.24万
• 依托单位: MARINE BIOLOGICAL LABORATORY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3320978
• 关键词: acetylcholinesterase; alkaline phosphatase; cell differentiation; cytochalasins; cytoplasm; dissection; early embryonic stage; egg /ovum; embryogenic cleavage; enzyme induction /repression; extrachromosomal DNA; fertilization; gel electrophoresis; gene expression; genetic transcription; histogenesis; immunoelectrophoresis; messenger RNA; monophenol monooxygenase; myogenesis; nonmammalian vertebrate embryology; phase contrast microscopy; saltwater environment; videotape /videodisc

This project will investigate the egg cytoplasmic determinants in the Ascidian embryo that appear to regulate various of the histospecific features of larval tissue differentiation. Particular emphasis will be placed on a reinvestigation of the muscle cell lineages and on a detailed description of simple muscle-specific characters that respond to control by the lineage-segregated determinant, notably a distinctive muscle acetylcholinesterase, other muscle proteins (myosin and tropomyosin), and simpler ultrastructural features of muscle development (myofilaments and myofibrils). The long-term goals of the project are in isolating the informational agent which influences or selects the pathway to muscle development, determining its chemical properties, and probing its mechanism of action. Microinjection and microsurgical methods will be used with embryos of Ciona intestinalis and Ascidia ceratodes to establish a biological assay for detecting activity of the determinant. Development of acetylcholinesterase and other specific muscle characters after microinjection of myoplasm into non-muscle lineage blastomeres will form the basis of the assay. The assay will be used to monitor the isolation, fractionation, and identification of determinant obtained from the unfertilized egg. Other procedures based on nuclear transplantation and combinations of early and later cytoplasms will provide additional means of assaying some of the temporal and functional properties of the determinant. To evaluate when muscle genes are first expressed (as functional mRNA), and thereby when determinants might first be acting, specific antisera against muscle proteins will be used to identify translational products in the Xenopus oocyte and rabbit reticulocyte lysate systems. These ascidian cytoplasmic factors that act to select and stabilize specific genetic pathways of phenotypic expression are examples of a precocious use in embryogenesis of the same gene regulatory elements that ordinarily function somewhat later in the development of all species, and which have not been easily accessible to study and isolation in higher organisms. Discoveries about the nature and function of egg cytoplasmic determinants in mosaic embryos have, therefore, obvious potential for contributing to an understanding of how gene activity is initially directed in specialized cells.

本项目将研究卵细胞质中的决定因素， 海鞘胚胎似乎调节各种组织特异性 幼虫组织分化的特征。 将特别强调 对肌肉细胞谱系的重新调查和详细的 描述简单的肌肉特定的字符，响应控制， 血统分离的决定因素，特别是一种独特的肌肉， 乙酰胆碱酯酶，其他肌肉蛋白（肌球蛋白和原肌球蛋白），和 肌肉发育的更简单的超微结构特征（肌丝和 肌原纤维）。 该项目的长期目标是隔离 影响或选择肌肉通路的信息因子 开发，测定其化学性质，并探讨其机理 的行动。 显微注射和显微手术方法将用于 玻璃海鞘和角状海鞘的胚胎，以建立一个 用于检测决定簇活性的生物测定法。 发展 乙酰胆碱酯酶和其他特定的肌肉特征， 将肌浆显微注射到非肌系卵裂球中将形成 分析的基础。 该试验将用于监测分离， 分馏，并鉴定从 未受精卵 基于核移植的其他程序， 早期和晚期细胞凋亡的组合将提供额外的手段， 分析的一些时间和功能特性的 行列式 评估肌肉基因何时首次表达（如 功能性mRNA），因此当决定因素可能首先起作用时， 将使用针对肌肉蛋白的特异性抗血清来鉴定 爪蟾卵母细胞和兔网织红细胞裂解物中的翻译产物 系统. 这些海鞘细胞质因子， 表型表达稳定化的特定遗传途径是实例 在胚胎发生中早熟使用相同的基因调控元件， 通常在所有物种的发育后期发挥作用， 在高等教育中， 有机体 关于卵细胞质的性质和功能的发现 因此，嵌合体胚胎中的决定因素具有明显的潜力， 有助于理解基因活动最初是如何被引导的 在专门的细胞中。