Freeze preservation of spermatozoa recovered from male mice that had been refrigerated after death.

摘要

Male mice of the ICR and BDF1 strains were killed and refrigerated at 4-6鳦 for various periods. Epididymal spermatozoa collected from the carcasses were frozen in liquid nitrogen. The viability of the spermatozoa after thawing was examined by in vitro fertilization, embryo culture and embryo transfer. When spermatozoa from freshly killed males was used 41-52% of freshly collected oocytes were fertilized. The fertilization rate after 1 day of refrigeration was 29-49%. The rate dropped as the refrigeration period increased, reaching 1-3% after 3 days. Partial zona dissection improved the fertilization rate when males had been refrigerated for 2 days (12-24% vs. 5-9%). High proportions of the resulting embryos developed in vitro, regardless of the strain of male mice used, the refrigeration period and or whether partial zona dissection had been performed. Embryos derived from spermatozoa from males that had been refrigerated for 2 days developed to term after transfer to recipients.