A CASE OF DECAPITATED SPERMATOZOA IN AN INFERTILE MAN

A case of headless or decapitated spermatozoa of an infertile man is r eported. The 33-year-old patient showed almost normal spermiogram exce pt for a high percentage (more than 90%) of headless spermatozoa. Both hypoosmotic swelling and zona-free hamster egg tests showed that most headless spermatozoa appeared to be normal in their function as tails . The ultrastructure of the ejaculated spermatozoa was observed using a surface replica method and by conventional ultrathin sectioning. The headless spermatozoa were almost normal in structure except for the a bsence of the head. Tailless heads were rarely observed. Varieties of ultrastructural abnormalities were observed in spermatozoa heads. Amon g them, abnormalities in the nuclear membrane covering the posterior p ole of the nucleus were prominent. The implantation fossa and the basa l plate were not formed. Instead, the nuclear membrane with numerous n uclear pores was found in this region. The decapitation seemed to take place between the region of the basal plate and the proximal centriol e.