XENOPUS CORTICAL GRANULE LECTIN/LIGAND INTERACTIONS

这项研究的长期目标是提供一种分子 受精时阻断多精受精反应的机制。 这 反应是受精过程中的基本步骤， 染色体的二倍体状态，通过精子的融合而恢复 和卵细胞核。 分子机制的知识 多精受精反应的控制。 性不孕 可以克服这种反应的缺陷， （避孕）可以潜在地使用这种机制的基础上， 对过程的基本理解。 凝集素-配体假说 用于阻止精子穿透。 卵皮质 精子中释放的颗粒凝集素触发了皮质反应， 分离、克隆并表征为糖蛋白结合分子。 然而，输卵管分泌的糖蛋白配体尚未被发现。 结构和功能特征。 具体目标是 应用是：1）确定两种形式的结构关系， 使用免疫学、氨基酸测序和克隆分离配体 方法. 2)表征分离的配体的功能性质 通过：a）复制原位凝集素配体的超微结构， 反应（所谓的受精层）使用分离的凝集素和 配体，B）使用以下方法建立配体的细胞外基质定位： 免疫细胞化学方法，和c）确定配体是否结合 精子通过其碳水化合物部分，并作为配体的功能， 精子表面受体 拟议研究的结果将 为皮质颗粒凝集素配体的结构提供理解 并验证了配体也在受精过程中发挥作用的假设， 与精子结合

The long term objective of the research is to provide a molecular mechanism for the block to polyspermy reaction at fertilization. This reaction is a fundamental step in the fertilization process insuring that the diploid state of the chromosomes, one restored by fusion of sperm and egg nuclei, is maintained. Knowledge of the molecular mechanisms of the polyspermy reaction will permit its control. Infertility caused by defects in this reaction may be overcome and prevention of fertilization (contraception) can potentially use this mechanism based on a fundamental understanding of the process. A lectin-ligand hypothesis for blocking sperm penetration has been proposed. The egg cortical granule lectin released in the sperm triggered cortical reaction has been isolated, cloned and characterized as a glycoprotein binding molecule. However, the oviductally secreted glycoprotein ligand has not been structurally and functionally characterized. The specific aims of this application are: 1) determine the structural relation of two forms of the isolated ligand using immunological, amino acid sequencing, and cloning methods. 2) characterize the functional properties of the isolated ligand by: a) reproducing the ultrastructure of the in situ lectin-ligand reaction (the so-called fertilization layer) using isolated lectin and ligand, b) establish the extracellular matrix location of the ligand using immunocytochemical methods, and c) determine if the ligand binds to sperm via its carbohydrate moieties and functions as a ligand for a sperm surface receptor. Results from the proposed research will provide a structural understanding for the cortical granule lectin ligand and test the hypothesis that the ligand also plays a fertilization role in binding to sperm.