The effect of sperm concentrations during preincubation and at insemination on fertilization of rat eggs in vitro

✍ Scribed by Nishimura, H. ;Niwa, K. ;Miyake, M. ;Iritani, A.

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 298 KB
• Volume: 223
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402230112

✦ Synopsis

Abstract

Rat epididymal spermatozoa, at a concentration of 40–65 × 10^4^ cells/ml, were preincubated for 5–5.5 hr and then added to eggs from superovu‐lated, immature rats. By 10–12 hr after insemination, 86% of the eggs had undergone fertilization, but many of them (41%) were polyspermic. When sperm were preincubated at almost the same concentration and for the time stated above, but then diluted to 1–3 × 10^4^ cells/ml before insemination, the number of fertilized eggs and the incidence of polyspermy were both reduced, being 56% and 5%, respectively. When a sperm concentration of 1–3 × 10^4^ cells/ml was used both during preincubation and at insemination, the fertilization rate and the degree of polyspermy were essentially zero. To achieve a fertilization rate of 60% or more, with polyspermy not in excess of 10%, a sperm concentration of 30–100 × 10^4^ cells/ml during preincubation and then diluted to approximately 1–3 × 10^4^ cells/ml at insemination appears to be optimal.