Ultrastructural study of anomalies of the acrosome in spermatozoa with irregular heads]

The study of the ultrastructure of spermatozoa having an irregular head, encountered in large number in semen of men supposed to be sterile, shows that the acrosome is often modified in its shape or its texture. In several samples the spermatozoa have either no acrosome or a small one, at a certain distance from the nucleus. In other cases the ratio between the segments of the acrosome is modified and the parallelism between the edges is not conserved. These acrosomes are often covered with a cytoplasmic velum the post acrosomal cape is missing. Finally the acrosome can be deformed by local expansions of the subacrosomal space, or by large gaps. Other anomalies which are less common have been observed. The elimination of possible artefacts and the comparison between these human anomalies and similar acrosomal anomalies of mammalian semen, are discussed in this paper.