An acrosomal abnormality in spermatids from infertile men.

A specific developmental abnormality of the acrosomes is described in the spermatids of two infertile men. The first change is the irregular folding of the acrosome membrane in the early round nucleated spermatids. Vesicles appear later in the subacrosomal space, in the nucleus and in the cytoplasm. All spermatids in the later steps of spermiogenesis were affected.