The effect of in vitro storage of hamster sperm on fertilization and early development

Abstract

The effects of storage of hamster sperm in vitro at temperatures above freezing on fertilization and early development were studied. Initially, female hamsters were inseminated artificially with epididymal sperm stored up to five days at 5°, 16°, or 23–25°C. Eggs were examined at the pronuclear stage for evidence of fertilization. The best conditions for the storage of hamster sperm were found to be 16°C in a 5% CO2 in air gas phase. Pre- and postimplantation development were then assessed following insemination of females with sperm stored at 16°C. An increased frequency of eggs with three pronuclei, a decrease in the number of pregnant females, and an increase in the number of resorption sites were found with increasing sperm storage time. Chromosome mosaicism and triploidy were encountered in 9.5-day embryos resulting from eggs fertilized by stored sperm. No chromosome abnormalities were found in a control group of embryos. Thus, storage of hamster epididymal sperm resulted in decreased fertility and an increased frequency of abnormal development.