Seminal Plasma Components Research Articles

Glycome complexity of human seminal plasma high molecular mass components: Evaluation of the contribution of acid-soluble glycoproteins/mucins and extracellular vesicles

This study was aimed at evaluation of the contribution of acid-soluble glycoproteins (ASG)/mucins and extracellular vesicles (EVs), yet unexplored components of human seminal plasma (hSP) to the complexity of its glycome. Gaining insight into the native presentation and distribution of glycans across hSP could help establish molecular environments supporting specific biological activities based on unique ligand capacities.Soluble and particulate fractions of hSP from healthy subjects were analyzed by gel filtration, electrophoresis, ion-exchange chromatography and a solid phase assay with immobilized charge-resolved glycospecies to test their reactivity with plant lectins, carbohydrate-binding antibodies and selected human lectins.Common O- and N-glycosylated species were detected on mixed or overlapped underlying protein scaffolds in both soluble and particulate fractions of hSP. Siaα2,6Gal and N-glycans were concentrated on EVs, whereas Siaα2,3Gal, T and Tn antigens were selectively associated with distinct glycospecies of ASG/mucins. Accessible ligands for the lectins, DC-SIGN and Siglec-9, were detected in all hSP components, but they preferentially bound to EVs glycospecies.Insight into the complexity of hSP glycans as recognition signals under normal physiological conditions could be of interest for regulation and possible modulation of its biological activity, as well as for biomarker potential related to male health.

Seminal vesicle proteins SVS3 and SVS4 facilitate SVS2 effect on sperm capacitation.

Mammalian spermatozoa acquire their fertilizing ability in the female reproductive tract (sperm capacitation). On the other hand, seminal vesicle secretion, which is a major component of seminal plasma, inhibits the initiation of sperm capacitation (capacitation inhibition) and reduces the fertility of the capacitated spermatozoa (decapacitation). There are seven major proteins involved in murine seminal vesicle secretion (SVS1-7), and we have previously shown that SVS2 acts as both a capacitation inhibitor and a decapacitation factor, and is indispensable for in vivo fertilization. However, the effects of SVSs other than SVS2 on the sperm have not been elucidated. Since mouse Svs2-Svs6 genes evolved by gene duplication belong to the same gene family, it is possible that SVSs other than SVS2 also have some effects on sperm capacitation. In this study, we examined the effects of SVS3 and SVS4 on sperm capacitation. Our results showed that both SVS3 and SVS4 are able to bind to spermatozoa, but SVS3 alone showed no effects on sperm capacitation. On the other hand, SVS4 acted as a capacitation inhibitor, although it did not show decapacitation abilities. Interestingly, SVS3 showed an affinity for SVS2 and it facilitated the effects of SVS2. Interaction of SVS2 and spermatozoa is mediated by the ganglioside GM1 in the sperm membrane; however, both SVS3 and SVS4 had weaker affinities for GM1 than SVS2. Therefore, we suggest that separate processes may cause capacitation inhibition and decapacitation, and SVS3 and SVS4 act on sperm capacitation cooperatively with SVS2.

Seminal plasma components differ between “good freezer” and “poor freezer” stallions

Seminal plasma components differ between “good freezer” and “poor freezer” stallions

Brief Report: Seminal Plasma Anti-HIV Antibodies Trigger Antibody-dependent Cellular Cytotoxicity: Implications for HIV Transmission.

Recent evidence from HIV vaccine trials in humans and non-human primates suggests that nonneutralizing antibody functions, such as antibody-dependent cellular cytotoxicity (ADCC), are an important component of vaccine-mediated protection. Whether anti-HIV ADCC antibodies are present in seminal fluid, however, is not known. We assessed whether anti-HIV antibodies within seminal plasma mediate ADCC and activate natural killer (NK) cells. Using matched blood and seminal plasma samples, we detected anti-HIV IgG within samples from all 11 HIV-infected donors. Furthermore, anti-HIV antibodies within the seminal plasma triggered detectable ADCC in 9 of 11 donors and activated NK cells in 6 of 11 donors. The ability of seminal plasma-derived IgG to activate NK cells in an anti-HIV antibody-dependent manner was enhanced when IgG were enriched and other seminal plasma components were removed. These observations have relevance for understanding natural immunity to HIV infection and provide assistance with HIV vaccine design.

Are genetic biomarkers the future of male fertility testing?

Men with infertility are subjected to numerous diagnostic tests in attempts to determine the nature of their condition. Initially, medical, surgical, and birth histories are elicited with investigations including semen analyses, hormonal panels, and imaging studies such as scrotal or trans-rectal ultrasounds. In cases of men with nonobstructive azoospermia (NOA), these inquiries may all return normal results. More specific testing involving karyotyping and Y-chromosome microdeletion analysis are then performed. When all of these results are normal, a definitive diagnosis must be pursued in the form of a testicular biopsy to determine the physiological ability of the testicle to conduct spermatogenesis.1 Novel biomarkers are constantly being explored to more accurately diagnose male fertility. Song et al.2 present a manuscript that eloquently illustrates the multiple approaches being taken to discover noninvasive, highly specific and sensitive genetic biomarkers for the diagnosis of testicular failure. The perfect biomarker would be all of these previously mentioned factors along with being able to diagnose the condition at an early stage, being both cost-effective and accurate, while exposing the patient to minimal risk.1 Genetic abnormalities are theorized to contribute to ~15%–30% of male factor infertility. Indeed, at present, large structural aberrations (as detected by karyotype analysis) and smaller genomic deletions (Y-microdeletion studies for the AZF/azoospermia factor, and the CFTR test for cystic fibrosis) are currently the best tests available to diagnose and explain certain etiologies in the infertile male. A serum genetic approach currently appears to be the most promising, given that semen for proteomic analysis is complicated by the components of both sperm and seminal plasma. The latter of which contains excretions from the prostate, seminal vesicles, and bulbouretheral glands. Karyotype studies have found ~2% of infertile men have karyotype abnormalities, a rate 5 times greater than the general population3 hinting at the possibilities for genetic screening. The holy grail of biomarker research is the creation of a genetic panel that would screen a wide number of known genes to accurately diagnose infertility and/or predict success at in vitro fertilization without the need for a surgical biopsy. Parallels can be derived from the realm of prostate cancer where the utilization of PSA has been enhanced with the use of biomarkers such as PCA3 and TMPRSS2-ERG.4 Companies such as Myriad Genetics Inc., have taken these concepts a step further offering the Prolaris prognostic screening test to measure tumor growth characteristics to help determine disease progression. Applying such a concept to male fertility makes an attractive proposition and could serve to eliminate the need for surgical intervention in males with infertility in general, and NOA in particular.

Introducing of a New Experimental Method in Semen Preparation: Supernatant Product of Adipose Tissue: Derived Mesenchymal Stem Cells (SPAS)

Human male infertility mostly is due to deficient semen parameters. One of the seminal plasma components providing chemical function of the ejaculate is growth factors functioning as paracrine, autocrine, and/or endocrine regulators of cell growth and differentiation. Adipose tissue-derived mesenchymal stem cells secret several proteins, such as cytokine, growth factors, and chemokine. On the other hand, due to contemporary semen preparation methods limitations, development of a new approach having least adverse effects and most efficiency is unavoidable. So, we decided to assess the effect of semen sample incubation with SPAS on semen parameters including motility, viability and DNA fragmentation. Semen sample of infertile men attending infertility treatment center whose were 30-40 years old was incubated with supernatant product of adipose tissue- derived mesenchymal Stem cells (SPAS). Motility parameters, viability and DNA fragmentation were evaluated using CASA software, eosin- nigrosine staining and halosperm kit respectively. Then conventional method of semen preparation for Intra Uterine Insemination (IUI)- Density gradient centrifugation (DGC)- was compared with SPAS method. Incubation of semen samples with SPAS (specially SP of 8×105 AD-MSCs for 40 minutes at 1:1 ratio) significantly increased motility parameters while decreased DNA fragmentation (p≤0.05) and has no effect in terms of semen viability. Also, SPAS was significantly more influential in improvement of motility parameters than DGC (p≤0.05). Since effect of growth factors in improvement of motility and DNA fragmentation is documented in previous studies, it seems that SPAS can be an effective method which provides all these factors together.

255 SEMINAL PLASMA PROTEINS: FUNCTIONAL ATTRIBUTES AND POTENTIAL MARKERS OF FERTILITY

Mammalian seminal plasma is a complex milieu containing, mostly, secretions of the epididymides and accessory sex glands. After ejaculation, proteins of the seminal fluid interact with sperm and participate in several events, including sperm motility, protection against immune reactions, oxidative processes and microorganisms, interaction with the oviduct epithelium, capacitation, acrosome reaction, and fertilization. Given these aspects, the present talk is focused on seminal plasma proteins and cross-species comparisons of their functional attributes. Experiments that will be presented used gel-based and shotgun proteomics. Binder of sperm proteins are major components of ruminant seminal plasma, while spermadhesins are predominant in the boar and deer (Mazama gouazoubira; Mazama nemorivag) seminal fluid. Annexins (rabbits), clusterin (peccaries: Pecari tajacu), and arginine esterase (coatis: Nasua nasua; dogs) are the most abundant proteins in seminal fluid of other species. Such diversity may reflect differences in how paternal factors modulate fertility. Studies have also reported empirical associations between seminal proteins, sperm freezability, and fertility indexes in ruminants and other domestic species. As evidenced by experiments using IVF, mainly in the bovine, specific seminal proteins influence the fertilizing capacity of both epididymal and ejaculated sperm, as well as early embryo development. In summary, fundamental knowledge gathered by studies of seminal plasma proteome can be used to identify molecular markers of fertility. Availability of such markers will potentially improve the outcome of artificial reproductive technologies. Diversity of seminal plasma composition, however, represents challenges for discovery of fertility markers in unique species. Seminal plasma proteins may also be related to new phenotypes, such as bull differences in sperm survival after sexation. This research was funded in part by the Brazilian Research Councils (CAPES and CNPq) and Ceara State Foundation for Scientific and Technological Development (FUNCAP).

Heterologous recombinant protein with decapacitating activity prevents and reverts cryodamage in ram sperm: An emerging biotechnological tool for cryobiology

During the last decades fundamental and applied aspects of mammalian ram sperm cryopreservation have been increasingly explored by scientists and biotechnologists. Many works report modifications in the composition of the freezing extenders and explore the beneficial and detrimental effects of seminal plasma or seminal plasma components in cryopreservation. Seminal plasma is known to contain stabilizing proteins, thereby this is a good start point to study the maintenance of membrane stability based on the basic knowledge of sperm physiology. However, seminal plasma composition is variable among rams and also the introduction of exogenous seminal plasma or its fractions to commercial semen can be associated with the transmission of viral diseases. Our work shows that a mouse protein, called SPINK3 (Serine Protease Inhibitor Kazal type 3) with decapacitating activity interacts with heterologous ram sperm when it is produced as a recombinant molecule. By immunocytochemistry assays we demonstrate that this protein (naturally expressed by mouse seminal vesicle under androgenic control) binds to the apical portion of both fresh and frozen ram sperm, the same localization described in mouse homologous sperm. Furthermore, it significantly improves sperm progressive motility compared to non-treated samples when it is added to freezing extenders and to dilution media after thawing. On the contrary, addition of SPINK3 does not modify sperm viability. The percentage of sperm with intact acrosome after ionophore induction was also significantly higher in sperm frozen in the presence of SPINK3 compared to control samples and the addition of SPINK3 after thawing significantly reduced both induced and non induced acrosomal loss, indicating that heterologous SPINK3 might act as a calcium inhibitor transport as described in mouse. Based on our results SPINK3 may find a place as a desirable biotechnological tool to achieve a higher proportion of competent sperm to fertilize.

Terminal Mannose Residues in Seminal Plasma Glycoproteins of Infertile Men Compared to Fertile Donors

The impact of seminal plasma components on the fertilization outcomes in humans is still under question. The increasing number of couples facing problems with conception raises the need for predictive biomarkers. Detailed understanding of the molecular mechanisms accompanying fertilization remains another challenge. Carbohydrate–protein recognition may be of key importance in this complex field. In this study, we analyzed the unique glycosylation pattern of seminal plasma proteins, the display of high-mannose and hybrid-type oligosaccharides, by means of their reactivity with mannose-specific Galanthus nivalis lectin. Normozoospermic infertile subjects presented decreased amounts of lectin-reactive glycoepitopes compared to fertile donors and infertile patients with abnormal semen parameters. Glycoproteins containing unveiled mannose were isolated in affinity chromatography, and 17 glycoproteins were identified in liquid chromatography-tandem mass spectrometry with electrospray ionization. The N-glycome of the isolated glycoproteins was examined in matrix-assisted laser desorption ionization mass spectrometry. Eleven out of 27 identified oligosaccharides expressed terminal mannose residues, responsible for lectin binding. We suggest that lowered content of high-mannose and hybrid type glycans in normozoospermic infertile patients may be associated with impaired sperm protection from preterm capacitation and should be considered in the search for new infertility markers.

Effect of dialysis of dog semen on sperm characteristics and some biochemical components of seminal plasma.

The aim of this study was to investigate the effect of dog semen dialysis on sperm characteristics and some biochemical components of seminal plasma. Whole ejaculates were dialyzed against Tris-citrate-fructose extender for a 5 h period at room temperature (using semi-permeable cellulose tubing of 12-14 kDa molecular weight cut-off). It has been demonstrated that the long-term dialysis of dog semen causes a significant decrease in sperm quality parameters and disrupts the biochemical properties of seminal plasma. This procedure requires further improvement.

Assessment of the Effect of Selected Components of Equine Seminal Plasma on Semen Freezability

Abstract In this study, selected components of seminal plasma in equine semen were evaluated. Levels of enzymes, electrolytes, microelements and some other components were observed. The aim of this study was to find some important differences between the levels of these components and the total sperm motility after freezing and thawing (freezability of the semen). Total of 32 ejaculates from 7 stallions were collected, assessed and prepared in 0,5 ml straws for freezing. After thawing, the sperm motility was analyzed and ejaculates were divided into two groups: “good” freezable and “poor” freezable. The only statistically significant difference between groups of „good“ and „poor“ freezable ejaculates was in the concentration of vitamin E in the seminal plasma. In the group of „good“ freezable ejaculates, the level of vitamin E was significantly lower (p≤0,05) than in the group of “poor” freezable ejaculates

On a matter of seminal importance.

Egg and sperm have, understandably, been the "stars" of mammalian fertilization biology, particularly because artificial reproductive technologies allow for fertilization to occur outside of the female reproductive tract without other apparent contributions from either sex. Yet, recent research, including an exciting new paper, reveals unexpected and important contributions of seminal plasma to fertility. For example, seminal plasma proteins play critical roles in modulating female reproductive physiology, and a new study in mice demonstrates that effects of some of these proteins on the female can even affect the health of her progeny. Furthermore, although several actions of seminal plasma have been conserved across taxa, male accessory glands and their products are diverse - even among mammals. Taken together, these studies suggest that the actions of seminal plasma components are important to understand, and also to consider in future development of assisted reproductive technologies (ART) for humans, farm species and endangered species of mammals.

Antimicrobial host defence peptide, LL-37, as a potential vaginal contraceptive

Does antimicrobial peptide, LL-37, inhibit sperm fertilizing ability? Our results indicate that LL-37 inhibits mouse and human sperm fertilizing ability. LL-37, a cationic antimicrobial peptide, exerts its microbicidal effects through the disruption of microbial cytoplasmic membranes following its interaction with microbial surface anionic phospholipids. ALL-38 (an LL-37 close analogue: LL-37 + Ala at the N-terminus) is produced in the vagina 2-6 h post-intercourse from its precursor hCAP-18, a seminal plasma component. At this time, motile sperm have already swum into the uterine cavity, thus unexposed to ALL-38. Since sperm contain a substantial amount of acidic sulfogalactosylglycerolipid (SGG) on their surface, treatment of sperm with LL-37 may cause their membrane disruption in an analogous manner to that occurring on microbial membranes. Mouse/human sperm treated (2-30 min) with LL-37 in a physiological concentration range (up to 10.8 µM) were assessed for SGG-dependent LL-37 binding, and parameters relevant to fertilizing ability, namely motility and intactness of the sperm acrosome and plasma membrane. Ability of mouse sperm to fertilize eggs in vitro was also evaluated. Each study was performed with greater than or equal to three different sperm samples. The efficacy of LL-37 to inhibit sperm fertilizing ability in vivo was determined in female mice (n = 26 each for LL-37 treatment and no treatment), using sperm retrieved from 26 males. Human sperm samples were donated by fertile men. LL-37 was chemically synthesized and was biotinylated for sperm binding studies. Sperm motility was assessed by videomicroscopy and the acrosomal status by Coomassie blue staining of acrosome-intact mouse sperm or the exposure of CD46, an inner acrosomal membrane protein, of acrosome reacted human sperm. Sperm membrane permeabilization/disruption was assessed by the loss of hypo-osmotic swelling response, an incorporation of Sytox Green (a membrane impermeable fluorescent DNA dye), and electron microscopy. Mouse IVF was scored by the presence of two pronuclei in eggs 6 h post-insemination. Ability of mouse sperm to fertilize eggs in vivo was determined by the pregnancy outcome of female mice injected transcervically with sperm with or without LL-37. Biotinylated LL-37 bound to both mouse and human sperm and the binding was partially dependent on sperm surface SGG. Mouse and human sperm became immotile and underwent a premature acrosome reaction upon treatment with LL-37 at 3.6 and 10.8 µM, respectively. The initial action of LL-37 on both mouse and human sperm appeared to be through permeabilization/disruption of sperm surface membranes evidenced by the loss of hypo-osmotic swelling response, Sytox Green staining and electron microscopy revealing ultrastructural damage. Mouse sperm treated with 3.6 µM LL-37 lost the ability to fertilize eggs both in vitro and in vivo. All 26 female mice inseminated with sperm and LL-37 did not become pregnant. No apparent damage to the reproductive tract was observed as revealed by histological characterization in LL-37-inseminated mice and these females resumed fecundity following mating with fertile males. Direct demonstration that LL-37 treated human sperm fail to fertilize eggs was limited by legal restrictions on obtaining human eggs for such use. Our results reveal selective inhibitory effects of LL-37 on sperm fertilizing ability in mice without apparent impairment to the female reproductive tract. LL-37 is therefore a promising candidate to be developed into a vaginal contraceptive with microbicidal activity. This work was supported by Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation (OPP1024509), Canadian Institutes of Health Research (MOP119438 & CCI82413) and International Collaboration and Exchanges NSFC of China (No.30611120525). There are no competing interests to declare.

Sperm motility and lactate production at different sperm concentrations

s / Journal of Equine Veterinary Science 34 (2014) 76 76 x106sperm/mL. Sperm recovery rate after centrifugation was lower in low concentration samples (p<0.001). Mean lactate concentration at T0 was the same in all three groups and directly correlated with raw semen volume (r1⁄40.5032; p1⁄40.0103). Lactate concentrations at T0 and T24 were not correlated. Compared to T0, lactate concentration was increased at T24when groupswere pooled, in C1, C4 and C8 groups separately, and lactate concentration was directly correlated with sperm concentration (r1⁄40.6080; p1⁄40.0002). At T24, lactate concentration was lower in C1 samples (p<0.001) when compared to lactate concentrations observed in higher sperm concentrations. In highly concentrated samples (C8), PTM was decreased after 8 hr but not PPM (p<0.01). After 24 hr, low concentration samples showed higher PTM and PPM (p<0.01). PTM and PPM after 24 hr were negatively correlated to lactate concentrations at T0 (r1⁄4-0.4568; p1⁄40.0217 and r1⁄4-0.4684; p1⁄40.0182). Concentrations of TM spermatozoa after 8 and 24 hr were correlated to lactate concentration at T24 (respectively, r1⁄40.5373; p1⁄40.0015 and r1⁄40.5320 and p1⁄40.0017). The same correlation was observed for the concentrations of PM spermatozoa after 8 and 24 hr (r1⁄40.5738; p1⁄40.0006 and r1⁄40.5579 and p1⁄40.0009, respectively). Concentration of NPM after 24 hr of storage was highly correlated to lactate concentration at T24 (r1⁄40.6767; p<0.0001). Fig. 1. Lactate concentration (mmol/L) according sperm concentration in samples and storage. Different letters in superscript indicate statistically different values. 4. Discussion Raw semen parameters are not associated with lactate concentration at T0, except the initial ejaculate volume. These data show that lactate concentration at T0 depends on collection conditions. It also shows that the negative effect of lactate on semen parameters is not observed immediately but during storage. In the present study, semen storage with high sperm concentration is rapidly deleterious for total motility, whereas progressive motility decreases between 8 and 24 hr. This delayed effect of high storage concentrations on progressive motility suggests that insemination with highly concentrated semen should not be performed later than 8 hr. Volume of the raw ejaculate is associated with lactate concentrations at T0 while raw semen concentration is not. Lactate concentration at T0 was negatively associated with progressive and total motility after 24 hr. This suggests that production and composition of seminal plasma could interfere with lactate concentration in raw semen and with its long-term conservation. Seminal plasma components should be studied to determine changes in metabolic products. A direct association between lactate concentration after 24 hr and total sperm concentration was observed, reflecting anaerobic metabolism by spermatozoa. Concentration of NPM spermatozoa was strongly correlated to lactate concentration after 24 hr of storage, suggesting an increased use of anaerobic glycolysis by the subpopulation of non-progressively motile spermatozoa. To conclude, lactate production is associated with total sperm concentration. It negatively affects preservation of total and progressive motility, showing an effect of by-products of anaerobic metabolism on long-term sperm storage. Moreover, our data show that non-progressively motile spermatozoa are highly associated with lactate concentration, and thus, anaerobic glycolysis. More studies are required to determine relative contributions of aerobiosis and anaerobiosis to sperm motility under different storage conditions.

Parental diet, pregnancy outcomes and offspring health: metabolic determinants in developing oocytes and embryos

The periconceptional period, embracing the terminal stages of oocyte growth and post-fertilisation development up to implantation, is sensitive to parental nutrition. Deficiencies or excesses in a range of macro- and micronutrients during this period can lead to impairments in fertility, fetal development and long-term offspring health. Obesity and genotype-related differences in regional adiposity are associated with impaired liver function and insulin resistance, and contribute to fatty acid-mediated impairments in sperm viability and oocyte and embryo quality, all of which are associated with endoplasmic reticulum stress and compromised fertility. Disturbances to maternal protein metabolism can elevate ammonium concentrations in reproductive tissues and disturb embryo and fetal development. Associated with this are disturbances to one-carbon metabolism, which can lead to epigenetic modifications to DNA and associated proteins in offspring that are both insulin resistant and hypertensive. Many enzymes involved in epigenetic gene regulation use metabolic cosubstrates (e.g. acetyl CoA and S-adenosyl methionine) to modify DNA and associated proteins, and so act as 'metabolic sensors' providing a link between parental nutritional status and gene regulation. Separate to their genomic contribution, spermatozoa can also influence embryo development via direct interactions with the egg and by seminal plasma components that act on oviductal and uterine tissues.

Lactotransferrin in Asian Elephant (Elephas maximus) Seminal Plasma Correlates with Semen Quality

Asian elephants (Elephas maximus) have highly variable ejaculate quality within individuals, greatly reducing the efficacy of artificial insemination and making it difficult to devise a sperm cryopreservation protocol for this endangered species. Because seminal plasma influences sperm function and physiology, including sperm motility, the objectives of this study were to characterize the chemistry and protein profiles of Asian elephant seminal plasma and to determine the relationships between seminal plasma components and semen quality. Ejaculates exhibiting good sperm motility (≥65%) expressed higher percentages of spermatozoa with normal morphology (80.3±13.0 vs. 44.9±30.8%) and positive Spermac staining (51.9±14.5 vs. 7.5±14.4%), in addition to higher total volume (135.1±89.6 vs. 88.8±73.1 ml) and lower sperm concentration (473.0±511.2 vs. 1313.8±764.7×106 cells ml−1) compared to ejaculates exhibiting poor sperm motility (≤10%; P<0.05). Comparison of seminal plasma from ejaculates with good versus poor sperm motility revealed significant differences in concentrations of creatine phosphokinase, alanine aminotransferase, phosphorus, sodium, chloride, magnesium, and glucose. These observations suggest seminal plasma influences semen quality in elephants. One- and two-dimensional (2D) gel electrophoresis revealed largely similar compositional profiles of seminal plasma proteins between good and poor motility ejaculates. However, a protein of ∼80 kDa was abundant in 85% of ejaculates with good motility, and was absent in 90% of poor motility ejaculates (P<0.05). We used mass spectrometry to identify this protein as lactotransferrin, and immunoblot analysis to confirm this identification. Together, these findings lay a functional foundation for understanding the contributions of seminal plasma in the regulation of Asian elephant sperm motility, and for improving semen collection and storage in this endangered species.

Sperm parameters and biochemical components of goat seminal plasma in the rainy and dry seasons in the Brazilian Northeast: the season's influence on the cooling of semen

The present study aimed to verify the caprine semen characteristics during dry and rainy seasons in the Brazilian Northeast, and the influence of these seasons on cooled semen. Seminal volume, concentration, percentage of motile cells, vigor and spermatic morphology, as well as biochemical profile (fructose, citric acid, P, Ca2+, Mg, total proteins and phospholipase A2 activity) were analyzed. It was observed a reduction (P&lt;0.05) in normal sperm morphology, fructose, citric acid, P, Mg and total protein concentration during the dry season, which did not affect the motility, vigor, volume and sperm concentration. Phospholipase A2 activity was increased during the dry season (P&lt;0.05). The analysis of the semen cooled at 4ºC during 48 hours showed reduction in total motility and vigor sperm during the dry season (P&lt;0.05). Based on these results, we conclude that the best period of year for caprine semen cooling is the rainy season.

Boar seminal plasma components and their relation with semen quality

Select boar seminal plasma (SP) components and their relation to semen quality were investigated. Thirty nine boars from three artificial insemination (AI) centers were divided into group A (GA: > 80% normal sperm and >70% motility) and group B (GB: < 80% normal sperm and < 70% motility). Each ejaculate was collected and semen volume, concentration, sperm motility (computer aided semen analysis; CASA), morphology, and vitality (both eosin nigrosin staining) were investigated. The SP was separated and analyzed for aspartate-amino-transferase (AST), γ-glutamyl-transferase (GGT), alkaline phosphatase (ALP) activity, and the concentrations of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), phosphate (PO43-), magnesium (Mg), selenium (Se) and zinc (Zn) were assessed. Repeated measures (2 months interval) were conducted in eight boars of GA from one AI center. The activity of GGT (r = -0.482) and ALP (r = -0.459) was moderately associated (p < 0.05) with ejaculate volume and strongly associated with concentration (r = 0.580 and r = 0.618, respectively; p = 0.000). Moderate associations (p < 0.05) were found between ALP (r = 0.439), GGT (r = 0.387), Na (r = -0.428), K (r = 0.354), and Se (r = 0.354) with progressive motility. The SP concentration of Na (r = -0.401), Cl (r = -0.521), and K (r = 0.350) was associated (p < 0.05) with normal morphology. Only Mg was associated (p < 0.05) with membrane damage (r = -0.335). The concentration of Na, Cl, and Zn (1681.0 vs. 1701.0 µg/dL) was different between groups (p < 0.05). Repeated measures showed significant differences in time but only for Na, Mg, and Zn (p < 0.05). In conclusion, several biochemical components of SP were related to semen quality. The analysis of biochemical parameters could provide extra information about reproductive health of AI boars.

The percentage of spermatozoa lost during the centrifugation of brown bear (Ursus arctos) ejaculates is associated with some spermatozoa quality and seminal plasma characteristics

Cryopreservation of brown bear (Ursus arctos) semen requires centrifugation to increase concentration and/or remove urine contamination. However, a percentage of the spermatozoa are lost in the process. This percentage varies considerably between males and ejaculates, and we have studied the effect of sperm quality and seminal plasma characteristics on the spermatozoa recovery rate after centrifugation. One hundred and thirty one sperm samples obtained from fifteen brown bear males by electroejaculation under general anaesthesia were used. The ejaculates were centrifuged 600×g for 6min. Motility was assessed by CASA, and acrosomal status (PNA-FITC) and viability (SYBR-14/propidium iodide) were determined by flow cytometry. Seminal plasma characteristics (albumin, alkaline phosphatase, calcium, cholesterol, creatine, glucose, glutamic oxaloacetic transaminase (GOT), lactate, lipase, magnesium, phosphate and total protein) were determined by a biochemical and gas analysis. Total motility (r=0.26; P=0.005) and cell viability (r=0.20; P=0.033) were positively correlated with the percentage of recovered spermatozoa. Sperm recovery was correlated with the concentration of several components of seminal plasma: negatively with glucose concentration (r=−0.47; P=0.005) and positively with the enzymes GOT (r=0.36; P=0.040) and lactate dehydrogenase (r=0.36; P=0.041). After sorting the data into classes according to sperm recovery (Low: 0–39, Medium: 40–69, High: 70–100), we observed that the samples with a lower recovery rate derived from ejaculates with lower values for TM, VAP and viability (P<0.05). Multiple regression analysis rendered two models to define the post-centrifugation spermatozoa recovery which included total motility and damaged acrosome or glucose, GOT and lactate dehydrogenase. We discuss these relationships and their implications in the electroejaculation procedure and the handling of the sample during centrifugation.

Seminal Plasma Components in Camelids and Comparisons with Other Species

Camelid semen is characterized by a highly viscous, low-volume ejaculate with a low concentration of spermatozoa that exhibit low progressive motility. The viscous seminal plasma is currently the major impediment to the development of assisted reproductive technologies (ARTs) in camelids. To advance ARTs such as sperm cryopreservation and artificial insemination in camelids, it is necessary to identify the cause of the viscosity and gain an understanding of the role of seminal plasma components on sperm function and fertility. Numerous compounds and proteins have been identified as mediators of sperm function and predictors of fertility in other livestock species, and understanding the importance of specific proteins has progressed the success of ARTs in these species. Current knowledge on the components of camelid seminal plasma is outlined, together with the implications of these components for the development of ARTs in camelids. The cause of semen viscosity, as well as proteins that are present in camelid seminal plasma, is described for the first time. Seminal plasma components are compared with those of other species to hypothesize their role in sperm function and fertility.