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.
Hough
Shelley R
SR
Department of Animal Science, Cornell University, Ithaca, New York 14853-4801, USA.
Kaproth
Michael T
MT
Foote
Robert H
RH
D020101:Acrosome Reaction / Q000502:physiology*; D000818:Animals; D002417:Cattle; D006224:Cricetinae; D007248:Infertility, Male / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D009865:Oocytes / Q000502:physiology; D010375:Pedigree; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure; D015044:Zona Pellucida / Q000502:physiology*