SIGNAL TRANSDUCTION AT FERTILIZATION

受精时的信号转导

• 批准号: 3312880
• 负责人: LAURINDA A. JAFFE
• 金额: $ 9.14万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-03-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3312880
• 关键词: Anura; G protein; Urodela; biological signal transduction; calcium; cell fusion; cell membrane; egg /ovum; electrophoresis; electrophysiology; exocytosis; fertilization; histology; hybridomas; ion transport; membrane channels; membrane potentials; membrane proteins; microelectrodes; monoclonal antibody; radioassay; receptor; saltwater environment; sperm

Within the first minute after sperm contact with a sea urchin or frog egg, a remarkable series of signals passes back and forth between sperm and egg plasma membranes. Contact with the fertilizing sperm causes ion channels to open in the egg plasma membrane, causing it to depolarize. This deplorization prevents other sperm from fertilizng the egg. Meanwhile, contact of the fertilizing sperm has set in motion a sequence of biochemical events which causes the egg to undergo exocytosis of its cortical vesicles and to begin development. One specific aim of this proposal involves examining the pathway coupling sperm-egg interaction to ion channel opening and cortical vesicle exocytosis. We will examine the hypothesis that the fertilizing sperm activates a receptor in the egg plasma membrane, and that the receptor activates a G-protein, which stimulates PIP2 phosphodiesterase, leading to InsP3 production and Ca2+ release. Ca2+ release is proposed to cause ion channel opening and exocytosis by a pathway involving a Ca2+/calmodulin- dependent phosphatase. The methods will involve microinjection as well as biochemical approaches, including the use of monoclonal antibodies. The other specific aim involves investigating how a change in the egg's membrane potential regulates sperm-egg fusion. We will examine two hypotheses: first, we will examine the possibility that the sperm membrane contains a positively charged fusion protein which accounts for the voltage-dependence of sperm-egg fusion. Second, we will examine an alternate possibility, that the egg membrane contains a sperm receptor whose exposure to sperm on the external surface of the egg depends on the egg's membrane potential. The methods will involve cross-species fertilization, lipid bilayer techniques, and application of monoclonal antibodies and proteases to eggs at various voltages. The significance of this work to the study of human development is that the cell biological prinicples we discover in our work invertebrates and amphibians will form a basis for future studies of mammals. The basic science background may ultimately find applications to practical problems such as contraception and infertility.

在精子接触海胆或 青蛙鸡蛋，一系列非凡的信号来回传递 在精子和卵质膜之间。 与 施肥精子会导致离子通道在卵等离子体中打开 膜，使其去极化。 这种a弱的能力阻止 其他精子从鸡蛋中肥料。 同时，接触 施肥精子已经使一系列生化 导致卵的事件发生皮质的胞吐作用 囊泡并开始开发。 该提案的一个具体目的涉及检查途径 耦合精子 - 蛋的相互作用与离子通道开口和 皮质囊泡胞吐作用。 我们将研究以下假设 受精的精子激活了卵等离子体中的受体 膜，并且受体激活G蛋白，该G蛋白 刺激PIP2磷酸二酯酶，导致INSP3产生 和Ca2+释放。 提议CA2+释放引起离子通道 涉及Ca2+/钙调蛋白的途径开放和胞吐作用 依赖性磷酸酶。 该方法将涉及显微注射 以及生化方法，包括使用 单克隆抗体。 另一个具体目的涉及调查如何改变 鸡蛋的膜电势调节精子融合。 我们将 检查两个假设：首先，我们将检查可能性 精子膜包含带正电荷的融合 蛋白质的蛋白质依赖于精子的电压依赖性 融合。 其次，我们将研究其他可能性， 卵膜包含一个精子受体，其暴露于 鸡蛋外表面上的精子取决于鸡蛋的 膜电位。 这些方法将涉及跨物种 受精，脂质双层技术和应用 单克隆抗体和蛋白酶的各种电压。 这项工作对人类发展研究的意义 是我们在工作中发现的细胞生物学prinicples 无脊椎动物和两栖动物将为以后的研究构成基础 哺乳动物。 基础科学背景可能最终发现 应用于避孕和等实际问题 不育。