Transport, capacitation and fertilizing ability of epididymal spermatozoa

✍ Scribed by Overstreet, J. W. ;Bedford, J. M.

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 733 KB
• Volume: 189
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401890208

✦ Synopsis

Abstract

Equal numbers of rabbit spermatozoa from the proximal cauda epididymidis and ejaculate of the same male were mixed and inseminated intravaginally. Their competitive performance in the same female was evaluated by identification of the two populations with x‐irradiation marking (fertilizing spermatozoon) and fluorescein isothiocyanate labelling (spermatozoa in the uterus and egg vestments). Following such mixed inseminations, epididymal spermatozoa from thirteen males fertilized 48% of 251 eggs recovered 50 hours after HCG injection and comprised 55%, 59% and 73% of spermatozoa in the perivitelline space, zona pellucida and mucin layer. When mixed spermatozoa from eight other males were inseminated 5 hours after HCG and the eggs were recovered 8 hours later (13 hours after HCG), epididymal spermatozoa accounted for 53% of the perivitelline and zona spermatozoa in 108 eggs and more than 50% of the uterine spermatozoa in seven of fifteen females. Cleavage of eggs fertilized by spermatozoa from the distal corpus epididymidis and ejaculate of the same male (eight males) was compared by insemination of the respective sperm populations into contralateral oviducts of the same female (sixteen females). There was no significant difference in the level of fertilization or the stage of cleavage 27 hours after insemination and HCG, whether eggs were fertilized by epididymal or ejaculated spermatozoa. These results indicate that once epididymal spermatozoa have acquired the capacity to penetrate the egg, they do not differ from ejaculated spermatozoa in their transport, capacitation, fertilizing ability or competence to sustain development of the egg to the sixteen cell stage.