SPERM-EGG INTERACTION: EXCITATION-ACTIVATION COUPLING

精子与卵子的相互作用：兴奋-激活耦合

• 批准号: 3316331
• 负责人: EDWARD L CHAMBERS
• 金额: $ 18.91万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-09-15 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3316331
• 关键词: acrosome; binding proteins; biological signal transduction; cell cell interaction; cell cycle; cell growth regulation; cell membrane; diffusion; electrical potential; electrodes; electrophysiology; ion transport; membrane fusion; membrane potentials; microinjections; receptor binding; saltwater environment; sea urchins; voltage /patch clamp

Fertilization involves two phases: (1) excitation (transduction of a signal from the sperm to the egg), and (2) activation (explosive release of Ca2+ and elevation of inositol triphosphate levels), which triggers the onset of development. The steps causing excitation and those which link excitation to activation are not known. Long term objectives are to determine the mechanism underlying sperm-induced excitation and the coupling of excitation to activation in the egg. The following will be determined: (1). the extent to which Na+, K+, H+ and Ca 2+ ions are responsible for the membrane currents during excitation and activation. Shifts of the reversal potentials caused by systematic ion substitutions and monitored electrophysiologically will allow us to determine the relative permeability for each ion. (2). the extent to which Na+, K+, H+, Ca 2+ ions affect excitation and/or the coupling of excitation to activation. Shifts in the voltage dependence of excitation, activation and sperm entry caused by systematic ion substitution will allow us to pinpoint ions which specifically affect these events. (3). Whether or not the sperm-egg fusion event precedes activation or even excitation. Membrane fusion may permit the diffusion of an excitatory molecule from the cytoplasm of the sperm to the egg. Three methods, will be used, namely, transfer of fluorescent markers between the gametes; patch clamp capacitance measurements; and electron microscopy of serial sections using improved methods. (4) Whether or not a sperm surface ligand-egg receptor interaction contributes to excitation of the egg. Bindin, the species specific, sperm-egg adhesive protein, as well as other sperm components will be examined for their ability to cause the same conductance changes as observed during excitation. The proposed research could ultimately provide information basic to the design of new contraceptive agents or to the understanding of certain types of infertility. The research is directed toward understanding what causes a quiescent cell to undergo activation, cell division and growth, and thus may be related to carcinogenesis. A combination of electrophysiology (membrane potential, resistance, and capacitance measurements, current and voltage clamp analysis, and patch clamp techniques), image processing methods, microinjection, and electron microscopy will be used.

受精包括两个阶段：（1）激发（受精的传导） 从精子到卵子的信号），以及（2）激活（爆炸性释放 Ca2+ 和三磷酸肌醇水平升高），这会触发 发育的开始。 引起激发的步骤和链接的步骤 激发到激活尚不清楚。 长期目标是 确定精子诱导兴奋的机制和 鸡蛋中的兴奋与激活的耦合。 以下将是 确定：（1）。 Na+、K+、H+ 和 Ca 2+ 离子的程度 负责激发和激活期间的膜电流。 系统离子取代引起的反转电位的变化 并进行电生理学监测将使我们能够确定 每个离子的相对渗透性。 （2）。 Na+、K+、H+、 Ca 2+ 离子影响激发和/或激发与 激活。 激发、激活和电压依赖性的变化 由系统离子替代引起的精子进入将使我们能够精确定位 特别影响这些事件的离子。 （3）。无论是否 精卵融合事件先于激活甚至激发。膜 融合可能允许兴奋性分子从 精子的细胞质到卵子。将使用三种方法，即 配子之间荧光标记的转移；膜片钳 电容测量；和使用连续切片的电子显微镜 改进的方法。 (4)精子表面是否有配体-卵子受体 相互作用有助于卵子的兴奋。宾丁，物种 特定的精卵粘附蛋白，以及其他精子成分 将检查它们引起相同电导变化的能力 激发期间观察到。 拟议的研究最终可以提供 设计新避孕药或避孕药的基础信息 了解某些类型的不孕症。 研究方向是 为了了解是什么导致静止细胞经历激活， 细胞分裂和生长，因此可能与癌变有关。 一个 电生理学（膜电位、电阻和 电容测量、电流和电压钳分析以及贴片 钳技术）、图像处理方法、显微注射和电子 将使用显微镜。