Bioscientifica Proceedings

For successful conception, fertilization-competent spermatozoa must be present at the site of fertilization in adequate numbers until ovulation has taken place. In pigs, a large volume of semen is delivered into the uterus. Most, if not all, of the inseminated liquid is voided from the vulva within a few hours after insemination and approximately 45% of the spermatozoa are lost. Large numbers of spermatozoa are also lost due to phagocytosis by polymorphonuclear leukocyte...

An overview is presented on the structure and function of the pig oviduct in relation to sperm capacitation and oocyte development in vivo. In pigs, a functional sperm reservoir is established in the uterotubal junction-isthmus when sperm deposition occurs before ovulation. Capacitation is assumed to occur in this location, and spermatozoa progress towards the ampullaryisthmic junction at about the time of ovulation as a consequence of capacitation and hyperacti...

Despite the importance of fertilization for animal production, species preservation and controlling reproduction, the molecular basis underlying fertilization is not well understood. More progress has been made in mice than in other mammals, but targeted deletion of specific genes in the mouse has often yielded unexpected results. The pig is also a useful animal to study, as large numbers of pig gametes can be acquired easily. However, it appears that the pig zona pelluc...

Considerable progress has been made in the in vitro production of pig embryos using improved methods for in vitro maturation (IVM) and fertilization (IVF). Despite the progress, polyspermic penetration remains a problem for in vitro-matured oocytes. Variation among boars, ejaculates and IVF protocols used in different laboratories appears to influence the incidence of polyspermy. Recent studies indicate that oviduct cells and their secretions p...