Observations on the acrosomal cap of fixed and unfixed bovine spermatozoa.

Abstract

The acrosomal cap of mammalian spermatozoa has received considerable attention from investigators using both light and electron microscopy. Recently, a comprehensive review of the subject has been published (Hancock, 1966). The structure of the acrosomal cap has been difficult to describe due to alterations which the cap undergoes during cell ageing, or after cell death (Hancock, 1953), and the labile nature of the acrosomal cap to chemical or physical processes involved in tissue preparation for microscopy (Bishop & Austin, 1957). The relationship of acrosome morphology and its alteration to the potentially fertile, motile, immotile or dead cell, as well as the sequence of alteration, must be more clearly understood before the role of this structure in fertilization can be fully evaluated. This report summarizes our observations on freshly collected bovine spermatozoa examined by light and electron microscopy following fixation and by differential interference contrast without fixation. The use