Comparative intracytoplasmic sperm injection (ICSI) in human and domestic species.

The current clinical use of intracytoplasmic sperm injection (ICSI) for the alleviation of male factor infertility has prompted a re-investigation of sperm injection techniques in a number of animal species. This report examines sperm injection of in vitro matured oocytes in the major domestic species and compares the results with the human. Ovine, bovine and porcine oocytes can undergo fertilization and at least limited development without exogenous activation either prior to or subsequent to injection. Porcine is temperature sensitive during fertilization and the early stages of embryo development. The oocytes of all three domestic species, particularly ovine, have a tendency to activate after the injection procedure regardless of the presence or absence of sperm. The implications for early development studies and the practical use of direct sperm injection for domestic species are discussed.