A role for seminal plasma in modulating pregnancy outcomes in domestic species

Abstract

Seminal plasma is a complex fluid produced by the accessory glands of the male reproductive tract. Seminal plasma acts primarily as a transport medium for sperm on its arduous journey through the male and then female reproductive tract following ejaculation. This spermatozoan expedition will hopefully result in the meeting of and resultant fertilization of an oocyte, perpetuating the genetic lineage of both sexes. Whereas seminal plasma has historically been perceived as only a transport medium providing a nutrient-rich fluid environment for sperm during this exchange of genetic material, new insights into a complex communication pathway between males and females has been unraveled in the past 30 years. This new research suggests seminal plasma as a method to promote early pregnancy success by modulating cellular and molecular adaptions of the maternal environment required to facilitate healthy, successful pregnancy outcomes. Whereas much work on this exciting new communication process has focused on mice and translation to human reproduction, here we review the current evidence in domestic species where artificial insemination in the absence of seminal plasma is routine. Improving artificial insemination in domestic species to optimize offspring health and productivity could have far-reaching impacts on agriculturally relevant species such as cattle, sheep, pigs and horses.Reproduction (2016) 152 R223-R232

Aquaporins in the male reproductive tract and sperm: Functional implications and cryobiology

“…Despite less documented than in the testis and excurrent ducts, AQPs are also present in accessory glands, which are crucial for their contribution to seminal plasma (see Bromfield, for review). In effect, AQP1 is found in the prostate and seminal vesicles (Brown et al., ) and AQP9 is found in the prostate and the coagulating gland of rats (Pastor‐Soler et al., ).…”

Effect of bovine seminal plasma on bovine endometrial epithelial cells in culture

“…However, in artificial insemination, semen can be deposited at the anterior os of the cervix, just inside the uterus or using a deep‐uterine technique (Bergeron, Crête, Brindle, & Manjunath, ). Thus varying amounts of SP can enter the uterus, as it is not removed during processing—it is merely diluted by adding semen extender (Bromfield, ). The proportion of bovine SP included in frozen semen depends on the sperm concentration, the intended number of sperm per straw and possibly on the predicted fertility of the bull.…”

“…A rough estimation of the amount of seminal plasma normally found in a bull semen dose can be obtained by assuming that the spermatozoa occupy a volume of 1.0–1.5 ml in raw semen (depending on the sperm concentration). Using this rough estimation, we found that commercial semen doses contain approximately 0.8%–12% SP (Bromfield, ; Hering, Oleński, Ruść, & Kaminski, ). The proportions of SP investigated here (75 μl and 300 μl) represent 1% and 4% of the cell culture medium; it is difficult to obtain a higher proportion in our cell culture system without depriving the cells of nutrients.…”

“…Seminal plasma (SP) promotes sperm motility and serves as a medium for transporting spermatozoa into the female (Bromfield, ; Maxwell, de Graaf, Ghaoui, & Evans, ; Poiani, ). It is produced by the accessory sex glands with small amounts of testicular and epididymal fluid (Bromfield, ). The major components of bovine SP include peptidase proteins, cytokines, enzymes, antioxidants, hormones, ions, sugar and lipid (Juyena & Stelletta, ).…”

“…Furthermore, differences in SP composition between low‐ and high‐fertility bulls have been reported, namely specific proteins (Killian, Chapman, & Rogowski, ; Morrell, Madej, Madej, & Stålhammar, ) and protein expression (D'Amours, Frenette, Fortier, Leclerc, & Sullivan, ; Moura, Koc, Chapman, & Killian, ). Endometrial epithelial cells can be exposed to, and interact with, SP during insemination (Bromfield, ; Robertson, ). However, no research has been performed on the impact of bovine SP from bulls of different fertility on bovine endometrial epithelial cells (bEEC).…”