Seminal Plasma Proteome: Promising Biomarkers for Bull Fertility

Abstract

The seminal plasma is a mixture of secretions from the testis, epididymis and male accessory sex glands. A number of seminal plasma proteins are associated with male fertility but most of these have not been studied in detail till now. Recently, proteomics has been used to show the differences in proteins profile in seminal plasma from high and low fertility bulls. For example, osteopontin, phospholipase A2, P25b, acidic seminal fluid proteins, a-L-fucosidase and cathepsin D are positively correlated with fertility of bulls and may act as useful fertility marker (s), while lipocalin-type prostaglandin D synthase, spermadhesin Z13, clusterin and ubiquitin are negatively correlated with fertility in bulls. Bovine seminal plasma proteins in seminal plasma act like a double-edged sword and showed a quadratic association with bull fertility. The physiological roles of the metalloproteinase-2 (TIMP-2), ecto-ADP-ribosyltransferase 5, nuclobindin, Niemann-Pick C2 and epididymal sperm-binding protein 1 and their relationship to bull fertility need further studies. This review summarizes the physiological functions of proteins of seminal plasma and their relation to bull fertility.

Markers for Sperm Freezability and Relevance of Transcriptome Studies in Semen Cryopreservation: A Review

“…While some speciic sperm protein markers facilitating good semen freezability have been identiied [10,24,39,40], their function depends on the presence of mRNA that can be translated into proteins in the spermatozoa. Moreover, the diferential expression paterns of certain classes of SP and sperm proteins following cryopreservation have been used as markers for semen freezability [3,6,10,[39][40][41][42][43][44]. Regarding boar semen, the physiological functions of SP and sperm proteins and their associations with freezability have been summarized in recent reviews by Yeste [3,10].…”

“…Regarding boar semen, the physiological functions of SP and sperm proteins and their associations with freezability have been summarized in recent reviews by Yeste [3,10]. In the bull, higher concentrations of a 26-kDa SP protein, known as lipocalin-type prostaglandin D synthase (L-PGDS), and a 13-kDa acidic seminal luid protein (aSFP) were associated with high-fertility bulls, suggesting the importance of these proteins as freezability markers [41]. Moreover, a fertilityassociated protein, osteopontin (OPN), an acidic glycoprotein occurring in the bovine SP, has been shown to induce capacitation and improve viability of spermatozoa by inhibiting the apoptotic pathways [39,41].…”

“…In the bull, higher concentrations of a 26-kDa SP protein, known as lipocalin-type prostaglandin D synthase (L-PGDS), and a 13-kDa acidic seminal luid protein (aSFP) were associated with high-fertility bulls, suggesting the importance of these proteins as freezability markers [41]. Moreover, a fertilityassociated protein, osteopontin (OPN), an acidic glycoprotein occurring in the bovine SP, has been shown to induce capacitation and improve viability of spermatozoa by inhibiting the apoptotic pathways [39,41]. Bovine SP proteins, collectively known as binder of sperm (BSP) proteins (BSP1, BSP 3, and BSP 5), bind to choline phospholipids in the sperm plasma membrane and are implicated in semen freezability [22,39,41,42].…”

“…Moreover, a fertilityassociated protein, osteopontin (OPN), an acidic glycoprotein occurring in the bovine SP, has been shown to induce capacitation and improve viability of spermatozoa by inhibiting the apoptotic pathways [39,41]. Bovine SP proteins, collectively known as binder of sperm (BSP) proteins (BSP1, BSP 3, and BSP 5), bind to choline phospholipids in the sperm plasma membrane and are implicated in semen freezability [22,39,41,42]. Recently, it has been conirmed that BSP1, one of the most abundantly expressed BSP proteins (representing approximately 25-47% of the total proteins in bovine SP), consists of four molecular forms that have varying cryoprotective efects on the bull spermatozoa [42].…”

“…Irrespective of the thawing procedure of frozen semen, it was reported that there was an increase in the expression levels of a few proteins, such as clusterin (CLU), histone H4 (HIST1H4A), and L-xylulose reductase (DCXR), whereas there was a decrease in the expression levels of several proteins, including apoptosis-inducing factor 1-mitochondrial (AIFM1), carbonic anhydrase 2 (CA2), acrosin (ACR), phosphoglycerate mutase 2 (PGAM2), inositol monophosphatase 1 (IMPA1), calmodulin (CALM1), cytochrome (CYC2), and NADH-cytochrome b5 reductase2 (CYB5R2) [43]. Besides the efect upon the sperm membrane protein P25b, an acrosome membrane-coating protein, cryopreservation causes a signiicant loss of several sperm-coating proteins, resulting in reduced post-thaw semen quality [10,[22][23][24][39][40][41][42][43][44][45]. It appears that the cryo-induced decrease in the levels of sperm proteins is probably atributed to protein degradation, membrane damage due to osmotic stress, and the subsequent freezing-thawing causing the elux of intracellular sperm constituents [6,43].…”