INTEGRINS AND EGG ACTIVATION AT FERTILIZATION

本研究的总体目标是确定整合素是否 参与受精时卵子的激活过程。这将 以多种方式进行调查。第一，存在和本地化 在α整合素亚基中，整合素亚基可能参与 在两栖动物受精中，将使用免疫印迹法测定， 免疫荧光技术。一个特定的β亚基将被寻找 使用免疫沉淀和免疫印迹。第二，职能作用 将使用功能阻断技术检测受精时整合素的表达。 抗整联蛋白亚单位抗体干扰精卵融合 和/或卵激活。第三个目标是确定是否 激活卵子表面的整合素刺激卵子的 活化，包括产生磷脂酰肌醇4，5- 二磷酸盐，膜电位的变化，细胞内 Ca2+，受精膜升高，皮层收缩， 第二极体的形成和肌动蛋白的积累在该地区的 精子进入最后一个目标是介绍 假定的哺乳动物整合素精子受体进入非洲爪蟾卵， 研究它们的表达是否允许小鼠精子与青蛙融合 鸡蛋和启动鸡蛋激活。这些研究将有助于我们 了解受精的基本生物学。这一背景可能 最终应用于实际问题，如避孕 和不孕症。

The overall objective of this research is to determine if integrins participate in the process of egg activation at fertilization. This will be investigated in a number of ways. First, the presence and localization of the alpha integrin subunit, an integrin subunit likely to participate in amphibian fertilization, will be determined using immunoblotting and immunofluorescence techniques. A specific Beta subunit will be looked for using immunoprecipitation and immunoblotting. Second, a functional role for integrins at fertilization will be examined using function-blocking antibodies against integrin subunits to interfere with sperm-egg fusion and/or egg activation. The third objective is to determine whether activating integrins on the egg surface stimulates events of egg activation, including production of phosphatidylinositol 4,5- bisphosphate, changes in membrane potential, an increase in intracellular Ca2+, elevation of the fertilization envelope, cortical contraction, second polar body formation, and actin accumulation in the region of sperm entry. The final objective is to introduce the subunits for the putative mammalian integrin sperm receptor into Xenopus eggs and to examine whether their expression allows mouse sperm to fuse with frog eggs and initiate egg activation. These studies will contribute to our understanding of the basic biology of fertilization. This background may ultimately find applications to practical problems such as contraception and infertility.