Rhesus macaque blastocysts resulting from intracytoplasmic sperm injection of vacuum-dried spermatozoa

Abstract

Sperm desiccation is an attractive approach for sperm preservation. In this study, we examined the feasibility and efficiency of intracytoplasmic sperm injection using vacuum-dried rhesus macaque sperm in CZB medium supplemented with 10% fetal bovine serum. A total of 109 MII oocytes were injected with 69 fresh ejaculated sperm and 40 vacuum-dried sperm. Cleavage occurred in 97% of oocytes injected with fresh, motile sperm and in 88% of oocytes injected with vacuum-dried sperm. Of the cleaved oocytes, 68% fresh sperm-injected oocytes and 74% of dried sperm-injected oocytes developed to the compact morula stage. Blastocyst development was comparable between fresh-injected (16%) and vacuum-dried-injected (17%) oocytes. Differences between treatment groups were not significant. Transmission electron microscopic observation of the blastocysts indicated no detectable differences between fresh sperm and dried sperm-derived embryos. We conclude that vacuum-dried rhesus macaque sperm are capable of inducing fertilization and development of pre-implantation embryos when sperm were dried under vacuum and microinjected into normal viable oocytes.