A microwell sperm penetration assay

Induction of the acrosome reaction and zona-free hamster oocyte penetration by a bull with complete teratospermia versus a half brother with normal sperm

A fertile bull producing normal sperm and a sterile half brother exhibiting 100% teratospermia were available to study an induced sperm acrosome reaction and oocyte penetration. Pedigree analysis indicated that this condition was inherited. Experiments were undertaken to study the induction of the acrosome reaction using dilaurylphosphatidylcholine (PC12) liposomes, because this procedure was previously established to be highly correlated with bull fertility. The sperm from each bull were incubated with several PC12 concentrations for varying time periods. The initial percentages of sperm from the sterile bull with intact, partially intact, and lost acrosomes were 67%, 18%, and 14%, respectively, vs 82%, 13%, and 5% for the fertile bull (P < .05). After incubation for 15 minutes with 50 microM PC12 liposomes the corresponding values were, respectively, 51%, 26%, and 19%; and 60%, 28%, and 12%. Thus, the differences after induction of the acrosome reaction, although significant (P < .05), were small. The number of sperm adhered to each oocyte averaged 22 and 10, respectively, for the fertile and sterile bulls, whereas 74% of the fertile bull sperm and only 11% of the sterile bull sperm penetrated oocytes. Mixing the sperm-oocyte complex during incubation and increasing the sperm concentration during incubation to compensate for differences in sperm motility did not markedly affect oocyte penetration by teratogenic sperm, which is consistent with this bull being sterile. In other studies, microinjection of this type of sperm was demonstrated to induce fertilization, so the consequences of using sperm with hereditary defects in assisted reproductive programs to overcome human male sterility may be a concern.

Semen analysis at the turn of the century: an evaluation of potential uses of new sperm function assays

Semen analysis is a critical assay in the evaluation of infertility and may yield critical information regarding the etiology and prognosis of many types of reduced male fertility. However, basic semen analysis does not directly measure sperm fertilizing capacity, or many of the biochemical events both prior to and subsequent to fertilization. In the last two decades numerous assays of sperm function have been developed. These assays can be classified as: 1) Assays of general biochemistry and ultrastructure, 2) Assays of zona binding and oocyte penetration, and 3) Assays of postpenetration events. Sperm function assays not only allow an accurate diagnosis of many infertilities not diagnosed by the semen analysis, but can also lead to improved treatment modalities. In this review, basic semen analysis and many sperm function assays are briefly reviewed. Novel uses of sperm function are demonstrated in brief case studies.

Review: in vitro spermicidal tests

This review analyzes in vitro spermicidal tests that have been used to evaluate the spermicidal activity of contraceptive products. Special requirements and processes in numerous technologies were also reviewed. Nonoxynol-9 (N-9) was used as an example of a vaginally delivered spermicidal agent, and its spermicidal potency was compared by various spermicidal tests, such as Sander-Cramer, computer-assisted semen analysis, hypoosmotic swelling test, cervical mucus penetration test, and flow cytometry, and advantages and disadvantages of each test were specified. This provides an insight into the different aspects of sperm functionality on which each spermicidal agent exerts its activity. A rationale of the best combination of in vitro spermicidal tests, with particular emphasis on a simple and efficient strategy that targets the complete fertility control, was explained.