Ram seminal plasma and its functional proteomic assessment

Abstract

Ejaculation results in the confluence of epididymal spermatozoa with secretions of the accessory sex glands. This interaction is not a prerequisite for fertilisation success, but seminal factors do play a crucial role in prolonging the survival of spermatozoa both in vitro and in vivo by affording protection from handling induced stress and some selective mechanisms of the female reproductive tract. Reproductive biologists have long sought to identify specific factors in seminal plasma that influence sperm function and fertility in these contexts. Many seminal plasma proteins have been identified as diagnostic predictors of sperm function and have been isolated and applied in vitro to prevent sperm damage associated with the application of artificial reproductive technologies. Proteomic assessment of the spermatozoon, and its surroundings, has provided considerable advances towards these goals and allowed for greater understanding of their physiological function. In this review, the importance of seminal plasma will be examined through a proteomic lens to provide comprehensive analysis of the ram seminal proteome and detail the use of proteomic studies that correlate seminal plasma proteins with ram sperm function and preservation ability.

Effect of Seminal Plasma Protein Fractions on Stallion Sperm Cryopreservation

“…Nevertheless, during boar sperm cryopreservation, they were unable to prevent capacitation-like changes [ 74 ]. As reviewed by Leahy et al, 2019 [ 75 ], variability in seminal plasma composition and seminal plasma proteins across species complicates the task to reveal their importance and function on spermatozoa. Differences in accessory sex glands and mating strategies result in protein and composition of seminal plasma diversity [ 76 ].…”

Sperm Cryodamage in Ruminants: Understanding the Molecular Changes Induced by the Cryopreservation Process to Optimize Sperm Quality

“…Many of the differentially abundant proteins between these sperm sources were mainly involved in energy metabolism, structural activity, redox homeostasis, immune response and fertilization. Although some proteins from seminal plasma are able to prevent or revert the cold-shock damage on sperm [87,117], other proteins from seminal plasma have been negatively correlated with sperm preservation ability [118]. For example, binder of sperm proteins (BSP), which are one of the most abundant protein families in bull and ram seminal plasma, exert a different effect during cryopreservation in these species.…”

From One Ejaculate to Another: Transference of Sperm Traits via Seminal Plasma Supplementation in the Ram

“…While seminal plasma was originally considered to function exclusively as a transport medium for sperm, it is now recognised to play an important role in many aspects of male reproductive success by influencing factors including sperm physiology, male/female interactions, and even offspring health [7][8][9]. Seminal plasma remodels the sperm surface and modifies the physiological response of spermatozoa through the provision of signalling factors and glycoproteins with sperm-binding properties [10]. Its composition varies among species, breeds, males, and ejaculates (e.g., across seasons and ages) [11,12], suggesting that seminal plasma composition is responsive to changes in selective pressures and environmental conditions.…”

“…Indeed, seminal plasma is routinely washed from sperm prior to use in ART as its persistent presence in IVF prevents capacitation and sperm-egg fusion [15]. However, seminal plasma supplementation during sperm processing can also be used to improve sperm function in ART [10,13], although outcomes are inherently variable due to variability in seminal plasma composition and the method of supplementation [16]. For example, the addition of seminal plasma can improve post-thaw sperm quality, but only when the seminal plasma is sourced from males with high freeze-tolerance ejaculates [17,18].…”