FUNCTION OF ELECTRICAL COUPLING IN EMBRYONIC TISSUE

胚胎组织中电耦合的功能

• 批准号: 3310247
• 负责人: MICHAEL V L BENNETT
• 金额: $ 4.82万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-09-29 至 1991-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3310247
• 关键词: Cephalopoda; Chironomidae; Malacostraca; Urodela; cell cycle; cell differentiation; cell motility; electrophysiology; embryo /fetus cell /tissue; embryogenic cleavage; fish; freeze etching; fresh water environment; gap junctions; ion transport; membrane channels; membrane permeability; microelectrodes; nonmammalian vertebrate embryology; photomicrography; saltwater environment; tissue /cell culture

The tunicate embryo, which proceeds from fertilization to swimming larva in about 18 hours (in the case of Ciona intestinalis), provides a remarkable preparation for the study of the role of intercellular communication in development. Preliminary data indicate compartmentation of dye coupling; the mechanisms whereby these compartments are formed will be investigated. Gap junctions in the ascidians show voltage dependence and the blastomeres exhibit two stable resting potentials sufficiently far apart to shut down junctional conductance and uncouple cells; these properties could lead to transient or reversible compartment formation. Determination of regional differences in resting potential, already indicated by differences in intensity of fluorescence observed with slow voltage sensitive dyes, will be validated with microelectrode measurement. Such regional differences must occur if voltage dependence of junctional conductance accounts for compartment formation. Alternatively the distribution of gap junctions might be the controlling factor. Measurement of coupling coefficients along with resting potentials would establish this mechanism of compartment formation. Some inductive interactions are known; electrical coupoing between participating cells will be assayed over time and compared to that between other cells where developmental information is not being transmitted. Effects of antibodies on junctional properties will be assayed and their use in exploration of the role of gap junctions in development explored. Studies of gap junctions from other embryos will be continued. Sensitivity to H and Ca will be assayed as part of an ongoing comparative study. Permeability will be correlated with conductance during treatments modulating junctional conductance. The results will provide information about the permeation process and indicate whether channel closure is all-or-none or graded. Reconstitution will be attempted in a three, rather than a two, compartment system. Improvements in perfusion media will be sought with a view to understanding cellular control of junction formation and removal, and parallel studies will be carried out on intact cells. Phosphorylation of junction protein has been demonstrated and pharmacological treatments of intact cells suggest an involvement in control of junctional conductance in a number of systems. The availability of antibodies and the imminent availability of the cDNA will make the cell biology of gap junctions accessible.

调皮胚胎从受精到游泳幼虫 大约18个小时（就塞奥纳肠而言），提供了一个非凡的 为研究细胞间通信的作用做准备 发展。 初步数据表明染料耦合的隔室； 这些隔室形成的机制将进行研究。 海沿岸的间隙连接显示了电压依赖性和囊泡。 展示两个稳定的休息电位，足够远，可以关闭 连接电导和脱离电池；这些特性可能导致 瞬态或可逆隔室形成。 确定区域 静息潜力的差异，已经通过差异表示 用缓慢的电压敏感染料观察到的荧光强度，将会 通过微电极测量验证。 这种区域差异 如果连接电导的电压依赖性为 车厢形成。 或者是间隙连接的分布 可能是控制因素。 耦合系数的测量 除了休息电位，将建立这种隔间机制 形成。 一些归纳相互作用是已知的。电轿跑车 在参与细胞之间将随着时间的流逝进行测定，并与此相比 在没有发展信息的其他单元之间 传输。 抗体对连接特性的影响将是 测定及其在探索间隙连接在 开发探索了。 将继续研究其他胚胎的间隙连接。 灵敏度 将H和CA作为正在进行的比较研究的一部分进行测定。 渗透率将与治疗过程中的电导相关 调节连接电导。 结果将提供信息 关于渗透过程，并指示通道关闭是否为 全有或无数分。 重构将在三个中尝试 比两个隔间系统。 灌注媒体的改善将是 寻求的是了解连接形成的细胞控制 并去除，并将平行研究对完整的细胞进行。 连接蛋白的磷酸化已被证明，并且 完整细胞的药理学治疗表明参与 控制许多系统中的连接电导。 可用性 抗体和cDNA的迫在眉睫的可用性将使细胞 差距连接的生物学可访问。