CHARACTERIZATION OF SPERM MEMBRANES

精子，在通过附睾体的过程中，获得了 通过体外受精试验对卵子进行受精。而当 很明显，许多精子特征的改变可能是重要的 从使用许多物种的各种研究中得知，膜的改性 代表了一个根本性的变化。许多关于变化的报道 精子进行顶体反应和卵子结合的能力 一个例子。这个实验室为世界上最大的 通过引入新的物理方法来量化膜特性的变化 方法评估膜状态并完成第一次分析 覆盖在顶体上的质膜的脂类成分。这些 已公布的数据，加上初步数据，与新推出的数据相结合 关于脂类组成的特定关系的概念 膜稳定性，以产生关于分子的唯一假说 精子获得能力所必需的事件，在 附睾体成熟和射精，发生顶体反应。 供检验的假设如下：脂类修饰 对于获得经历顶体的能力是必不可少的 反应。精子被视为在以下方面扮演被动角色 膜的改性，因为它们的表面的变化是由 与特定脂蛋白供体和脂交换蛋白的相互作用 在它们周围的液体中被发现。转让的专一性是这样的 我们测量到的去除一摩尔的变化 磷脂酰乙醇胺和一摩尔磷脂酰胆碱的插入 加上覆盖在细胞膜上的三个摩尔的胆固醇 顶体导致质膜的内侧半部分受到“压力” 双层的。在沉积后由未知因素释放的这种应力 女性生殖道，导致顶体反应。 为了验证这一假设，本文概述了五个项目。第一个遗嘱 比较体外诱导顶体反应的多种检测方法。这个 第二个和第三个将产生足够的数据来表征脂质 男性生殖道液中的交换蛋白和脂蛋白。这个 第四个项目将建立必要的方法来系统地改变 体外精子膜组成(模拟原位变化)，而 期末项目将提供已知更改的影响的汇总测试 脂质成分对未成熟附睾精子受精能力的影响 一种体外诱导的顶体反应。

Sperm, during transit through the epididymis, acquire the capacity to fertilize ova as assessed via in vitro fertilization assays. While alterations in many spermatozoal features may be important, it is clear from a variety of studies using many species that modification of membranes represents one essential change. The many reports of changes in the ability of sperm to undergo the acrosome reaction and ova binding serves as one example. This laboratory has made major contributions to the quantification of changes in membrane features by introducing new physical methods to assess membrane status and completing the first analysis of the lipid components of the plasma membrane overlying the acrosome. These published data, plus preliminary data, are combined with newly introduced concepts regarding the specific relationship of lipid composition on membrane stability to yield a unique hypothesis regarding the molecular events that are necessary for sperm to acquire the capacity, during epididymal maturation and ejaculation, to undergo the acrosome reaction. The hypothesis presented for test is as follows: Lipid modification is essential to the acquisition of the capacity to undergo the acrosome reaction. Sperm are viewed as serving in a passive role with regard to membrane modifications, in that alteration of their surfaces results from interaction with specific lipoprotein donors and lipid exchange proteins found in their surrounding fluids. The specificity of the transfer is such that the our measured changes of removal of one mole of phosphatidylethanolamine and insertion of one mole of phosphatidylcholine plus three moles of cholesterol in the plasma membrane overlying the acrosome results in a "stressed" inner half of the plasma membrane bilayer. Release of this stress, by unknown factors after deposition in the female tract, results in the acrosome reaction. To test this hypothesis, five projects are outlined. The first will compare multiple assays of the in vitro induced acrosome reaction. The second and third will yield data sufficient to characterize the lipid exchange proteins and lipoproteins of male reproductive tract fluids. The fourth project will establish methods necessary to systematically alter sperm membrane composition in vitro (to mimic in situ changes) while the final project will provide a summary test of the effect of known changes in lipid composition on the capacity of immature epididymal sperm to undergo an in vitro induced acrosome reaction.