What is the relevance of seminal plasma from a functional and preservation perspective?

Extracellular vesicles in seminal plasma: A safe and relevant tool to improve fertility in livestock?

“…Overall, as shown in Fig. 1, the concerted mixture of sEVs exert specific actions on capacitation and fertilizing capacity (reviewed by de Andrade et al, 2022) or even the immune responsiveness of the female against paternally derived antigens (Tamessar et al, 2021). It has been established that ncRNA in semen differentially contributes to reproduction, their relative expression even explaining levels of fertility when explored within spermatozoa (Alvarez-Rodriguez et al, 2020b;.…”

“…To favour gene dissemination from best sires, attempts were made to increase the number of AI-doses of liquid, cooled or deep-frozen semen produced per ejaculate, yet maintaining similar levels of fertility as after natural mating. Such plan, intended for all livestock, remains burdened by species-and individualdifferences observed when lowering sperm numbers per AI-dose, likely by the modification of the fluids surrounding the spermatozoa (de Andrade et al, 2022). In most livestock species, the original seminal plasma (SP) is largely extended, whereas in others -as goats or humans-even eliminated (Chang, 1957;Pavaneli et al, 2019), questioning is role or its potential damaging effects for cryopreserved semen or when performing in vitro fertilization (IVF) (reviewed by de Andrade et al, 2022).…”

“…Such plan, intended for all livestock, remains burdened by species-and individualdifferences observed when lowering sperm numbers per AI-dose, likely by the modification of the fluids surrounding the spermatozoa (de Andrade et al, 2022). In most livestock species, the original seminal plasma (SP) is largely extended, whereas in others -as goats or humans-even eliminated (Chang, 1957;Pavaneli et al, 2019), questioning is role or its potential damaging effects for cryopreserved semen or when performing in vitro fertilization (IVF) (reviewed by de Andrade et al, 2022). For IVF, epididymal or ejaculated, washed spermatozoa, i.e., spermatozoa deprived from almost all SP are customarily used (Henkel, 2012).…”

“…There is also evidence, although we still ignore many underlying mechanisms, that the SP can, per se, i.e., if added separately from spermatozoa, modulate fertility (de Andrade et al, 2022). Embryo survival, implantation, placental development, farrowing and litter size improved when additional homologous/pools of SP were infused to the female genital tract of several species (reviewed by Rodriguez-Martinez et al, 2021).…”

“…Indeed, identifying what it is in SP that induces these changes is mandatory. Logically, the task is major, and many studies have been already done or are undergoing, particularly focusing on the differences between the actions of SP under natural mating, and those registered when the SP is retrieved from collected semen and differentially handled in vitro, preserved, and used later for analyses and/or as additive (de Andrade et al, 2022). We strongly suggest, to diminish reiteration of data being presented and discussed here, that readers consult recent extensive comparative reviews we and our long-lasting co-authors have already published, where we attempted to dissect the composition of the SP, considering various species for their specific reproductive anatomy, mating behavior, and semen deposition sites during mating or AI (Rodriguez-Martinez et al, 2021).…”