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，确保 染色体的二倍体状态，通过精子融合恢复的状态 和卵核，保持不变。对分子机制的认识 多精受精反应将允许它的控制。由以下原因引起的不孕症 这种反应的缺陷可能会被克服，并防止受精 (避孕)可以潜在地使用这种机制，基于 对这一过程的基本理解。凝集素-配体假说 已经提出了阻止精子穿透的方法。卵皮质层 颗粒凝集素在精子中释放，引发了皮质反应 分离、克隆并鉴定为糖蛋白结合分子。 然而，输卵管分泌的糖蛋白配体还没有 具有结构和功能特征的。这样做的具体目的是 应用是：1)确定两种形式的结构关系 用免疫学、氨基酸序列测定和克隆技术分离配体 方法：研究方法。2)表征分离配体的功能性质 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 配基，b)建立配基的细胞外基质位置 免疫细胞化学方法，以及c)确定配体是否与 精子通过其碳水化合物部分和作为一种配体的功能 精子表面受体。拟议研究的结果将 提供对皮质颗粒凝集素配体的结构理解 并验证了配体也在受精过程中起作用的假设 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.