Seminal Plasma Proteins: What Role Do They Play?

Abstract

Citation Rodríguez‐Martínez H, Kvist U, Ernerudh J, Sanz L, Calvete JJ. Seminal Plasma Proteins: What Role Do They Play? Am J Reprod Immunol 2011; 66 (Suppl. 1): 11–22Problem Semen is a heterogenous and complex cell suspension in a protein‐rich fluid with different functions, some of them well known, others still obscure.Method of study This paper reviews, comparatively, our current knowledge on the growing field of proteomics of the SP and its relevance in relation to the in vivo situation, for the sake of reproductive biology, diagnostics and treatment.Results Ejaculated spermatozoa, primarily bathing in cauda epididymal fluid, are (in vitro) bulky, exposed to most, if not all, secretions from the accessory sexual glands. In vivo, however, not all spermatozoa are necessarily exposed to all secretions from these glands, because sperm cohorts are delivered in differential order and bathe in seminal plasma (SP) with different concentrations of constituents, including peptides and proteins. Proteins are relevant for sperm function and relate to sperm interactions with the various environments along the female genital tract towards the oocyte vestments. Specific peptides and proteins act as signals for the female immune system to modulate sperm rejection or tolerance, perhaps even influencing the relative intrinsic fertility of the male and/or couple by attaining a status of maternal tolerance towards embryo and placental development.Conclusions Proteins of the seminal plasma have an ample panorama of action, and some appear responsible for establishing fertility.

Characterization of the porcine seminal plasma proteome comparing ejaculate portions

“…Consequently, the quantitative differences on SP-proteins among ejaculate portions showed in the present study should be considered statistically robust, but the conservative statistic procedure developed might overlook some other expressed proteins that could also show quantitative differences between ejaculate portions, although to a lesser degree and always open to misinterpretation. The absence of quantitative differences in SP-protein expression between P1 and P2 may be understandable, as P1 and P2 together comprise the first naturally occurring ejaculate fraction (SRF), whose SP has a common origin, albeit having amount differences [5]. to some specific sperm functionalities, as membrane stability and permeability (GLB1L3, [46]; ARSA, [47]), capacitation (HEXB, [48]), acrosome reaction (GP2, [49]), fertilizing ability (LCN-5, [50]) or sperm-zone pellucid binding (ARSA, [51]).…”

“…Seminal plasma is a complex mixture composed of exocrine secretions from the testis, epididymis and the male accessory sexual glands, containing a wide variety of both organic and inorganic components, being proteins the main one and probably the major conditioners of the reproductive success involving the use of processed semen [5,6].…”

“…As indicated by Park et al [14], extensive and comprehensive knowledge of SP-proteome is an essential prerequisite before SP-proteins could be used as biomarkers of sperm functionality, or even fertility. Unfortunately, the boar SP-proteome is still far from being completely decoded, requiring further research [5,15]. Despite the economic relevance, porcine is currently the livestock species with the fewer SP-proteins identified, less than 100 [15,16], which contrasts with other livestock species, such as poultry or ovine with more than 600 SP-proteins identified.…”

“…The boar ejaculate is fractionally emitted, alike other mammalian species such as equine and even human [5]. Then, it is possible to visually differentiate two main fractions during the ejaculation, a first fraction named sperm rich fraction (SRF), containing most of the total sperm, and a second named post-SRF, largest in volume but containing very few sperm.…”

Gelatin Binding Proteins in Reproductive Physiology

“…Spermatozoa develop in the testes, mature in the epididymis and are ejaculated along with seminal fluids, which provide nutrition and protection for sperm deposited in the female reproductive tract. This fluid contains a liquid fraction known as seminal plasma, which is secreted from various accessory sex glands such as the epididymis, seminal vesicles, ampullae, prostate and the bulbourethral glands [1].…”