The Mammalian Sperm Surface: Studies with Specific Labeling Techniques

Abstract

This chapter focuses on electron microscope studies of spermatozoa, which include specific information concerning distributions of chemical entities on the sperm or acrosomal surface. Of particular interest are studies relating to some of the dynamic transformations, such ascapacitation, the acrosome reaction, and membrane fusion). Although much attention has been directed to some of these aspects in invertebrate systems; this chapter discusses the findings made on mammalian spermatozoa. Information will continue to accumulate with respect to the constellation of specific chemical sites and receptors on the sperm surface over the next few years. Hopefully, patterns will emerge that will be useful in analyzing the biological activities of spermatozoa throughout their life cycle and that will have some general validity beyond particular species characteristics. Of special interest here are capacitation, the acrosome reaction, and sperm-egg interactions. To pursue these ends and have confidence in our observations, one must utilize more effective procedures for maximizing the particular cellular stages for analysis with fine-structural techniques. Some methods for synchronizing the activities of spermatozoa undergoing various physiological reactions are already available, such as the use of Ca 2+ for triggering the acrosome reaction in vitro.