Protein profile of the seminal plasma of collared peccaries (Pecari tajacu Linnaeus, 1758)

Molecular Biomarkers of Canine Reproductive Functions

The aim of the current study is to review potential molecular biomarker substances selected so far as useful for assessing the quality of dog semen. Proteins, lipids, carbohydrates, and ions can serve as molecular biomarkers of reproductive functions (BRFs) for evaluating male reproductive health and identifying potential risk factors for infertility or reproductive disorders. Evaluation of BRF levels in semen samples or reproductive tissues may provide insights into the underlying causes of infertility, such as impaired sperm function, abnormal sperm-egg interaction, or dysfunction of the male reproductive tract. Molecular biomarker proteins may be divided into two groups: proteins that are well-studied, such as A-kinase anchoring proteins (AKAPs), albumins (ALBs), alkaline phosphatase (ALPL), clusterin (CLU), canine prostate-specific esterase (CPSE), cysteine-rich secretory protein 2 (CRISP2), lactotransferrin (LTF), metalloproteinases (MMPs), and osteopontin (OPN) and proteins that are not well-studied. Non-protein markers include lipid-based substances (fatty acids, phosphatidylcholine), carbohydrates (glycosaminoglycans), and ions (zinc, calcium). Assessing the levels of BRFs in semen samples may provide valuable information for breeding management and reproductive assessments in dogs. This review systematizes current knowledge that could serve as a starting point for developing practical tests with the use of biomarkers of canine reproductive functions and their predictive value for assisted reproductive technique outcomes and semen preservation.

Comparison between commercial media and TRIS-egg yolk extender in the refrigerated storage of collared peccary semen at 17°C

To assist in the conservation of collared peccary, it is important to strengthen semen processing protocols. The aim of this study was to compare the effects of different commercial extenders (BTS; NUTRIXcell+ and PRIMXcell Ultra) and TRIS + egg yolk on the functional and morphological aspects of collared peccary semen stored at 17 °C for 48 hours. Ten ejaculates obtained by electroejaculation were divided into 4 aliquots and diluted in the respective extenders, then stored in a biological incubator at 17 °C for 12, 24, 36, and 48 hours. The samples were evaluated for kinetic parameters, membrane functionality, membrane integrity, mitochondrial activity, morphology, and sperm-binding capacity. At the end of storage (48 h), promising results were found for motility parameters, with TRIS + egg yolk (71.0 ± 4.6%) being more efficient than NUTRIXcell+ (38.9 ± 10.9%) (P < 0.05) and similar to BTS (42.9 ± 11.9%) and PRIMXcell Ultra (46.8 ± 10.8%). The results for membrane integrity and mitochondrial activity were around ∼30-50%, with TRIS being the only extender to preserve both parameters (58.9 ± 5.3 and 59.2 ± 5.6%) for up to 48 hours, respectively (P < 0.05). Finally, the extenders could guarantee 60% membrane functionality and ∼ 60-70% normal sperm morphology, as well as similar binding capacity among the groups. In conclusion, TRIS + egg yolk is effective in preserving the sperm parameters of collared peccary semen at 17 °C for 48 hours, while PRIMXcell Ultra and BTS are viable alternatives for this purpose.

Proteomic Insights into Seminal Plasma and Spermatozoa Proteins of Small-Spotted Catsharks, Scyliorhinus canicula: Implications for Reproductive Conservation in Aquariums

In the ex situ conservation of chondrichthyan species, successful reproduction in aquaria is essential. However, these species often exhibit reduced reproductive success under human care. A key aspect is that conventional sperm analyses do not provide insights into the functional competence of sperm. However, proteomics analysis enables a better understanding of male physiology, gaining relevance as a powerful tool for discovering protein biomarkers related to fertility. The present work aims to build the first proteome database for shark semen and to investigate the proteomic profiles of seminal plasma and spermatozoa from small-spotted catsharks (Scyliorhinus canicula) related to the underlying adaptations to both natural and aquarium environments, thereby identifying the reproductive impact in aquarium specimens. A total of 305 seminal plasma and 535 spermatozoa proteins were identified. Among these, 89 proteins (29.2% of the seminal plasma set) were common to both spermatozoa and seminal plasma. In the seminal plasma, only adenosylhomocysteinase protein showed differential abundance (DAP) between wild and aquarium animals. With respect to the spermatozoa proteins, a total of 107 DAPs were found between groups. Gene Ontology enrichment analysis highlighted the primary functional roles of these DAPs involved in oxidoreductase activity. Additionally, KEGG analysis indicated that these DAPs were primarily associated with metabolic pathways and carbon metabolism. In conclusion, we have successfully generated an initial proteome database for S. canicula seminal plasma and spermatozoa. Furthermore, we have identified protein variations, predominantly within spermatozoa, between aquarium and wild populations of S. canicula. These findings provide a foundation for future biomarker discovery in shark reproduction studies. However, additional research is required to determine whether these protein variations correlate with reproductive declines in captive sharks.

Different Methods for Seminal Plasma Removal and Sperm Selection on the Quality and Fertility of Collared Peccary Sperm

Methods for seminal plasma (SP) removal and the selection of collared peccary sperm for fertilization were compared. The experiments evaluated the following: the (I) impact of centrifugation for SP removal before swim-up for sperm selection and (II) a comparison of different Percoll^® gradient densities (PG 45-90% and PG 35-70%). Non-selected sperm served as the control. Sperm quality was assessed based on motility patterns, morphology, membrane functional integrity, viability, reactive oxygen species (ROS), glutathione (GSH), and DNA integrity. Subsequently, the most successful group in the previous experiment and washing by centrifugation (WC) were compared for motility patterns and fertilization using pig oocytes. Swim-up decreased motility and enhanced ROS compared to the control. Centrifugation before swim-up harmed integrity and viability compared to the control. PG 45-90% (96.8 vs. 69.7 vs. 40.7 µm/s) allowed for a better velocity average pathway (VAP), a better velocity straight line, and better linearity (LIN) than those of the control and PG 35-70% (88.4 vs. 56.0 vs. 27.3 µm/s). Thus, PG 45-90% was used for fertilization. PG 45-90% obtained a higher VAP, a higher amplitude of the lateral head, straightness, and higher LIN than those of the control and WC. Cleavage (25.2-26.3%) and morula (8.1-10.5%) rates did not differ between the groups. Therefore, PG 45-90% and WC were efficient in isolating collared peccary sperm capable of fertilizing pig oocytes.

Impact of Seminal Plasma Composition on Sperm Freezability in Wild Mammals: A Review

This review was designed to summarize the most important information around seminal plasma composition and discuss its impact on the freezability of wild mammal semen samples. Seminal plasma is made up of various biochemical constituents, including ions, lipids, proteins, enzymes, and sugars, which vary between species in response to the presence and size of any relevant accessory glands. The biochemical constituents of seminal plasma may change as a result of age, individual variability, and seasonality. These constituents are responsible for supporting different functions in sperm cells, contributing to motility, acrosomal reaction, and fertilization events. A detailed understanding of seminal plasma biochemistry may help to optimize semen freezing protocols, enabling the dynamic alteration in diluents to allow for increased sperm viability rates after thawing.

Influence of antibiotics on bacterial load and sperm parameters during short-term preservation of collared peccary semen

Studies on semen and sperm cells are critical to develop assisted reproductive technologies for the conservation of the collared peccary. The objective of the study was to compare the effect of different antibiotics on the bacterial load and sperm quality during short-term storage of peccary semen. Fresh semen samples from 10 males were extended in Tris-egg yolk or Tris-Aloe vera supplemented with streptomycin-penicillin (SP; 1 mg/mL - 1000 IU/mL or 2 mg/mL - 2000 IU/mL) or gentamicin (30 µg/mL or 70 µg/mL) before storage at 5°C. Bacterial load and sperm motility, membrane integrity and function, mitochondrial activity, and morphology, were evaluated at different time points for 36 h. The SP and gentamicin treatments concentration inhibited (p < 0.05) bacterial growth for 36 h regardless of the extender. Compared to the other treatments, Tris-egg yolk plus 70 µg/mL gentamicin maintained the sperm parameters for longer, including total motility (41.9 ± 6.1%) at 24 h, and membrane integrity (58.3 ± 2.1%) at 36 h. In contrast, the highest SP concentration in both extenders impaired sperm membrane integrity at 36 h (p < 0.05). For the liquid storage of collared peccary semen, it therefore is recommended to use Tris extender supplemented with egg yolk and gentamicin (70 µg/mL).

Mapping the major proteome of reproductive fluids and sperm membranes of rams: From the cauda epididymis to ejaculation

The present study evaluated the major proteome of ram seminal plasma and the main secretions that contribute to its formation, such as the cauda epididymal and accessory sex gland fluids. The study also investigated sperm membrane protein profiles before and after ejaculation. First, semen was collected from six rams (using artificial vagina) to obtain seminal plasma and ejaculated sperm. Then, rams were vasectomized for collection of accessory sex gland fluid (using artificial vagina). Next, rams were slaughtered and cauda epididymal fluid (CEF), seminal vesicle fluid, bulbourethral gland fluid and cauda epididymal sperm were properly collected. Proteins from reproductive fluids and sperm membranes were analyzed by 2-D SDS-PAGE, tandem mass spectrometry and bioinformatics. There we 386 proteins and 256 isoforms identified in all samples. The most abundant seminal plasma proteins were BSP1, BSP5 and spermadhesins (bodhesin-2 and spermadhesin Z13-like). These proteins were present in similar patterns in maps of accessory sexgland fluid, with very low quantities in the CEF and absent in the bulbourethral gland secretion. Thus, practically all BSPs and spermadhesins come from seminal vesicles. Bulbourethral gland fluid brought bactericidal/permeability-increasing protein-containing Family A member 1 isoforms, superoxide dismutase [Cu-Zn] and betamicroseminoprotein to seminal plasma. CEF was the major provider of clusterin, epididymal-specific lipocalin-5-like isoform, epididymal secretory gluthathione peroxidase, epididymal secretory protein E1 and prostaglandin-H2 D-isomerase to seminal plasma. Albumin came from all reproductive fluids. BSPs and spermadhesins were present in 2-D maps of ejaculated sperm but absent in cauda epididymal sperm. These proteins come from the seminal vesicles and bind to sperm at the moment of ejaculation. Other proteins of ejaculated and epididymal sperm membranes were mostly associated to energy production, cell adhesion and proteolytic activity (ATP synthases, disintegrin, metalloproteinase domain-containing protein 32, carboxypeptidase Q and cytosol aminopeptidase). In conclusion, there is a well-orchestrated sequence of events to form the major seminal plasma proteome, with specific contributions from cauda epididymis, seminal vesicles and bulbourethral glands. The present data contribute to a better understanding of male reproductive biology and how sperm functions are affected by the noncellularmicro environment of semen.

Protein signatures of seminal plasma from bulls with contrasting frozen-thawed sperm viability

The present study investigated the seminal plasma proteome of Holstein bulls with low (LF; n = 6) and high (HF; n = 8) sperm freezability. The percentage of viable frozen-thawed sperm (%ViableSperm) determined by flow cytometry varied from -2.2 in LF to + 7.8 in HF bulls, as compared to the average %ViableSperm (54.7%) measured in an 860-sire population. Seminal proteins were analyzed by label free mass spectrometry, with the support of statistical and bioinformatics analyses. This approach identified 1,445 proteins, associated with protein folding, cell-cell adhesion, NADH dehydrogenase activity, ATP-binding, proteasome complex, among other processes. There were 338 seminal proteins differentially expressed (p < 0.05) in LF and HF bulls. Based on multivariate analysis, BSP5 and seminal ribonuclease defined the HF phenotype, while spermadhesin-1, gelsolin, tubulins, glyceraldehyde-3-phosphate dehydrogenase, calmodulin, ATP synthase, sperm equatorial segment protein 1, peroxiredoxin-5, secretoglobin family 1D and glucose-6-phosphate isomerase characterized the LF phenotype. Regression models indicated that %ViableSperm of bulls was related to seminal plasma peroxiredoxin-5, spermadhesin-1 and the spermadhesin-1 × BSP5 interaction (R2 = 0.84 and 0.79; p < 0.05). This report is the largest dataset of bovine seminal plasma proteins. Specific proteins of the non-cellular microenvironment of semen are potential markers of sperm cryotolerance.

Shotgun proteome analysis of seminal plasma differentiate boars by reproductive performance

There is a need to identify subfertile boars before they enter into the breeding herd. Seminal plasma proteins are essential for normal sperm function and transport and play an important role in fertilization. The objective of this study was to use liquid chromatography tandem mass spectrometry for shotgun proteome analysis to investigate whether differences in boar fertility phenotype can be differentiated by seminal plasma protein abundance. Following 50 breedings, boars were categorized into one of four phenotypes: high farrowing rate and total born (HFHB; n = 9), high farrowing rate with low total born (HFLB; n = 10), low farrowing rate and total born (LFLB; n = 9), and low farrowing rate with high total born (LFHB; n = 4) that were distinct (p < 0.05) from each other by these variables. There were 506 proteins measured in at least one sample across all animals. There were 245 high confidence proteins and 56 were differentially abundant between the high fertility phenotype (HFHB) and at least one of the three subfertile groups. Findings support that seminal plasma protein profiles are distinct between boars with different fertility phenotypes.

Proteomic identification of boar seminal plasma proteins related to sperm resistance to cooling at 17 °C

The modern pig industry relies on extensive use of artificial insemination with cooled semen. It is important that semen doses maintain their quality during processing, transport and storage before insemination to guarantee maximum fertility rates. However, ejaculates may respond differently to liquid preservation at 17 °C, despite the optimal quality assessed before cooling. Thus, the aim of this study was to identify differences in seminal plasma proteome of ejaculates with a higher or lower seminal resistance to storage at 17 °C. A total of 148 ejaculates from 65 sexually mature healthy boars were classified as: High Resistance to cooling (HR, total motility > 60% at 144h) and Low resistance to cooling (LR, total motility <60 at 72h). To identify differentially expressed seminal plasma proteins between HR and LR ejaculates, ten ejaculates of each group were analyzed by 2D SDS-PAGE and ESI-Q-TOF mass spectrometry. The proteins associated with HR ejaculates were cathepsin B (spot 2803 and 6601, p < 0.01); spermadhesin PSP-I (spots 3101 and 3103, p < 0.05); epididymal secretory protein E1 precursor (spot 2101, p < 0.05) and IgGFc binding protein (spot 1603, p < 0.01). The protein associated with LR group was the Major seminal plasma PSPI (spot 9103, p < 0.01). To our knowledge, this is the first report of the association of boar seminal plasma proteins to semen resistance to cold storage at 17 °C. These results suggest the use of these proteins as biomarkers for semen resistance to preservation at 17 °C.

Composition of collared peccary seminal plasma and sperm motility kinetics in semen obtained during dry and rainy periods in a semiarid biome

The aim of this study was to evaluate environmental effects in a semiarid region on collared peccary seminal plasma content and sperm motility. Ejaculates from 12 mature males were obtained during the peak of rainy and dry periods of the Caatinga biome. Samples were evaluated for semen volume, pH, as well as sperm concentration, morphology, osmotic response, membrane integrity, chromatin condensation, and kinetic motility. Seminal plasma was evaluated for ions and organic compounds. The values for chloride, iron, magnesium, phosphorus, citric acid, cholesterol, triglycerides, total proteins, albumin, and fructosamine were similar during the dry and rainy periods; however, concentrations of fructose (849.2 mg/dL compared with 119.4 mg/dL) and calcium (32.3 mg/dL compared with 15.6 mg/dL) were greater during the rainy compared with dry period (P <  0.05). There were correlations (P <  0.05) among values for semen variables and biochemical contents, particularly between fructose and sperm velocity average pathway (r = 0.65), velocity straight line (r = 0.78), velocity curvilinear (r = 0.57), amplitude lateral head (r = 0.62), linearity (r = 0.41), and subpopulation with a medium velocity (r = -0.75). Furthermore, values for relative humidity were positively correlated with concentrations of fructose (r = 0.49), while air temperature (r = -0.43) and wind velocity values (r = 0.66) were negatively affected by concentration of fructose (P <  0.05). There were novel results regarding collared peccary seminal plasma biochemistry indicating there are important correlations with values for semen variables that are affected by the environment in a semiarid climate.

Proteome of cat semen obtained after urethral catheterization

The binding of seminal plasma (SP) proteins by spermatozoa plays an important role in the regulation of sperm epididymal maturation, motility gaining in female reproductive tracts and sperm-egg interaction. The aim of the study was to analyze the SP and sperm extracts proteome of cat (Felis catus) semen. The seminal plasma and spermatozoa were obtained by urethra catheterization from 10 male cats. Proteins were extracted using RIPA buffer and separated by electrophoresis (SDS-PAGE). The gels were analyzed using MultiAnalyst software. The proteins were subsequently analyzed using NanoUPLC-Q-TOF/MS. UniProt database-supported identification resulted in 106 proteins identified in the cat SP and 98 proteins in the extracts of spermatozoa. Based on a gene ontology analysis, dominant molecular functions of feline SP proteins were binding, catalytic, and antioxidant activity (56%, 33%, and 11% of cases, respectively). The molecular functions of sperm extracts proteins were mainly involved in catalytic activity (41%) and binding (23%). The proteins present in both, the SP and spermatozoa's extracts, were: serum albumin (ALB), semenogelin 2 (SEMG 2), clusterin (CLU), lactoferrin (LTF), prostatic acid phosphatase (ACPP), prolactin inducible protein (PIP), negative elongation factor E (NELF-E) and ectonucleotide pyrophosphatase (ENPP3). Protein-protein interactions analysis showed significant connection for 12 proteins in the cat semen. The seminal plasma proteins which, with high probability score, participate in important metabolic pathways are: glutathione peroxidases (GPx5 and 6), prostatic acid phosphatase (ACPP), β-hexosaminidase (HEXB), polymeric immunoglobulin receptor (pIgR) and serpin family F member 1 (SERPINF1). For sperm protein extracts it were: pyruvate dehydrogenase (PDHB), succinate-CoA-ligase (SUCLA2), malate dehydrogenase (MDH2), ATP synthase F1 subunit alpha (ATP5F1A) and tubulin beta (TUBB).

Major seminal plasma proteome of rabbits and associations with sperm quality

The present study was conducted to describe the major seminal plasma proteome of rabbits and potential associations between seminal proteins and semen criteria. Semen samples were collected from 18 New Zealand adult rabbits, and seminal plasma proteins were analyzed by 2-D SDS-PAGE and tandem mass spectrometry. Sperm motility, vigor, concentration, morphology and membrane sperm viability were evaluated. Rabbits ejaculated 364 ± 70 million sperm/ml, with 81 ± 6.1% motile cells, 3.8 ± 0.2 vigor and 66.7 ± 2.5% sperm with normal morphology. Based on the viability and acrosome integrity assay, there were 65.8 ± 2.5% live sperm with intact acrosome and most spermatozoa had both intact acrosome and functional membrane. On average, 2-D gels of rabbit seminal plasma had 232 ± 69.5 spots, as determined by PDQuest software (Bio Rad, USA). Mass spectrometry allowed the identification of 137 different proteins. The most abundant proteins in rabbit seminal plasma were hemoglobin subunit zeta-like, annexins, lipocalin, FAM115 protein and albumin. The intensity of the spots associated with these five proteins represented 71.5% of the intensity of all spots detected in the master gel. Multiple regression models were estimated using sperm traits as dependent variables and seminal plasma proteins as independent ones. Also, sperm motility had positive association with beta-nerve growth factor and cysteine-rich secretory protein 1-like and a negative one with galectin-1. The percentage of rabbit sperm with intact membrane was related to seminal plasma protein FAM115 complex and tropomyosin. Then, the population of morphologically normal sperm in rabbit semen was positively linked to carcinoembryonic antigen-related cell adhesion molecule 6-like and down regulated by seminal plasma isocitrate dehydrogenase. Based on another regression model, the variation in the percentage of live sperm with intact acrosome was partially explained by the amount of leukocyte elastase inhibitor and the peptidyl-prolyl cis-trans isomerase A in the rabbit seminal fluid. The current study reports the identification of 137 proteins of rabbit seminal plasma. Major proteins of seminal secretion relate primarily to prevention of damages caused by lipid peroxide radicals and oxidative stress, membrane functionality, transport of lipids to the sperm membrane and temperature regulation. Moreover, finding seminal plasma proteins as indicators of semen parameters will improve assisted reproductive technologies.

Environmental effects on collared peccaries (Pecari tajacu) serum testosterone, testicular morphology, and semen quality in the Caatinga biome

The objective of the study was to understand the influence of climatic variations in a semiarid environment on serum testosterone, testicular morphology and semen quality in collared peccaries (Pecari tajacu). Reproductive metrics (semen quality, testicular morphometry and testosterone serum profiles) of 10 mature males were measured monthly for 18 months. Meteorological data (rainfall, air temperature, relative humidity, wind speed and radiant heat load) also were recorded during the same period. Rainfall regimes were classified in different classes (Class 1: months with no rain; Class 2: months with up to 50 mm of rain; and Class 3: months with >50 mm of rain). Among rainfall classes, average air temperature (°C) and relative humidity (%) were different. Climatic changes between rainfall classes did not lead to overall variations of testicular size, testosterone production, and semen metrics. However, relative humidity recorded before semen collection (one day, one week, or over 51-55 days) was positively correlated (P < 0.05) with semen motility metrics (total motility, beat cross frequency and straightness) and sperm subpopulations (medium and static sperm), as well as with volume. Negative correlations (P < 0.05) were revealed between air temperature and the same semen motility patterns and volume. Additionally, radiant head load measured on the day of semen collection negatively influenced (P < 0.05) sperm straightness. This study demonstrates for the first time that no seasonal changes could be detected overt the 18-month period on the serum testosterone, testicular morphology and semen quality of collared peccaries raised in the Caatinga biome; however, it is expected that long term environmental changes will influence the reproductive physiology of species leaving in that habitat.

Proteomic landscape of seminal plasma associated with dairy bull fertility

Male fertility is the ability of sperm to fertilize the egg and sustain embryo development. Several factors determine the fertilizing capacity of mammalian sperm, including those intrinsic to sperm and components of the seminal plasma. The present study analyzed the seminal fluid proteome of Bos taurus and potential associations between proteins and fertility scores. Mass spectrometry coupled with nano HPLC allowed the identification of 1,159 proteins in the dairy bull seminal plasma. There were 50 and 29 seminal proteins more abundant in high (HF) low fertility (LF) bulls, respectively. Based on multivariate analysis, C-type natriuretic peptide, TIMP-2, BSP5 and sulfhydryl oxidase indicated relationship with HF bulls. Clusterin, tissue factor pathway inhibitor 2, galectin-3-binding protein and 5′-nucleotidase were associated with LF bulls. Abundance of NAD(P)(+)-arginine ADP-ribosyltransferase, prosaposin and transmembrane protein 2 proteins had the highest positive correlations with fertility ranking. Quantities of vitamin D-binding protein, nucleotide exchange factor SIL1 and galectin-3-binding protein showed the highest negative correlations with fertility ranking. A fertility ranking score was calculated and the relationship with these proteins was significant (Spearman’s rho = 0.94). The present findings represent a major and novel contribution to the study of bovine seminal proteins. Indicators of fertility can be used to improve reproductive biotechnologies.

Cryopreservation of collared peccary (Pecari tajacu L., 1758) epididymal sperm using extenders based on Tris and powdered coconut water (ACP®-116c)

The aim of this study was to establish a functional freezing–thawing protocol for epididymal sperm of collared peccaries (Pecari tajacu L., 1758) by comparing different extenders. The epididymal sperm from 12 sexually mature males was recovered by retrograde flushing using Tris-based or coconut water-based (ACP®-116c) extenders. After initial evaluation, samples were diluted and frozen with the same extenders to which 20% egg yolk and 6% glycerol were added. After 2 weeks, thawing was performed at 37°C/60 s and sperm motility, vigour, morphology, functional membrane integrity, sperm viability, sperm plasma membrane integrity, and a computer-assisted semen analysis (CASA) were assessed. In addition, to evaluate the survival of frozen–thawed sperm, a thermal resistance test (TRT) was executed. Samples preserved using Tris were in better condition compared with those preserved using ACP®, showing higher values for most assessments performed, including CASA and the TRT (P<0.05). After determining Tris to be the better of the two extenders, additional samples were thawed using different thawing rates (37°C/60 s, 55°C/7 s, 70°C/8 s). Sperm thawed at 37°C/60 s had the greatest preservation (P<0.05) of viability (54.1 ± 5.9%) and functional membrane integrity (43.2 ± 5.4%), and had higher values for various CASA parameters. In conclusion, we suggest the use of a Tris-based extender added to egg yolk and glycerol for the cryopreservation of epididymal sperm obtained from collared peccaries. In order to achieve better post-thawing sperm quality, we suggest that samples should be thawed at 37°C/60 s.

Seminal plasma proteomes and sperm fertility

During ejaculation, the spermatozoa are transported by the seminal plasma, a fluid resulting from secretions originating mainly from the prostate and the seminal vesicles in mammals. The interaction of the seminal plasma with spermatozoa induces binding of seminal proteins onto the sperm surface and membrane remodeling potentially impacting the sperm transport, survival and fertilizing ability in the female genital tract. The seminal plasma also contains peptides and proteins involved in the inflammatory and immune response of the female tract. Therefore the seminal plasma proteome has been investigated in a large range of taxa, including mammals, birds, fishes and insect species. The association of the seminal plasma with semen preservation or fertility identified proteic markers of seminal plasma function in domestic species. This review summarizes the current knowledge in seminal plasma proteomes and proteic markers of sperm preservation in animal species.

Seminal plasma and sperm proteome of ring-tailed coatis (Nasua nasua, Linnaeus, 1766)

Ring-tailed coati is listed as a species of least concern in the International Union for Conservation of Nature (IUCN) Red List, however, there has been a sharp decline in their population. The present study was conducted to evaluate the major proteins of both seminal plasma and sperm in ring-tailed coatis. Semen sample was collected from three adult coatis and evaluated for their morphological characteristics. Further, the sample was centrifuged to separate spermatozoa from seminal plasma, and then stored in liquid nitrogen. The seminal plasma and sperm proteins were subjected to one-dimensional (1-D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and identified by mass spectrometry. Gene ontology and protein networks were analyzed using bioinformatics tools. Based on sperm concentration and average protein content of the semen, the concentration of protein/spermatozoon was found to be 104.69 ± 44.43 μg. The analysis of SDS-PAGE gels showed 20.3 ± 3.1 and 17 ± 2 protein bands/lane for seminal plasma and sperm, respectively. In-gel protein digestion and peptide analysis by mass spectrometry revealed 238 and 246 proteins in the seminal plasma and sperm, respectively. The gene ontology analysis revealed that the proteins of seminal plasma mainly participated in cellular (35%) and regulatory (21%) processes. According to their cellular localization, seminal plasma proteins were categorized as structural (18%), extracellular (17%), and nuclear (14%) proteins with molecular functions, such as catalytic activity (43%) and binding (43%). The sperm proteins were also involved in cellular (38%) and regulatory (23%) processes, and mainly categorized as extracellular (17%), nuclear (13%), and cytoplasmic (10%) proteins. The major molecular functions of the sperm proteins were catalytic activity (44%) and binding (42%). These results indicated that the seminal plasma of ring-tailed coati has an array of proteins that can potentially modulate several sperm functions, from sperm protection to oocyte binding. However, further studies are necessary to interpret the roles of these major seminal plasma proteins in coatis.

Sperm membrane proteins associated with the boar semen cryopreservation

This study aimed to define sperm membrane protein markers of semen freezability of boars with the aid of a proteomic approach. Semen from fourteen adult boars were subjected to slow freezing and rapid thawing. After thawing, sperm vigor and motility were analyzed, and based on these results, animals were separated into two groups: good (GFEs) and poor freezability (PFEs). Sperm membrane proteins were extracted and subjected to two-dimensional electrophoresis. Stained gels were analyzed by computerized resources to indicate differentially expressed protein spots, that were identified by mass spectrometry. Six animals showed good freezability with average sperm vigor and motility of 2.2±0.8 and 41.8±22.9, respectively, whereas eight boars showed poor freezability, with 1.9±0.6 and 26.8±17.5 of sperm vigor sperm motility, respectively. An average of 263±62.2 spots per gel and 234.2±54.6 of spots consistently present in all gels were detected. The intensities of five spots were significantly different between groups. Fc fragment of IgG binding protein and lactadherin were more intense in the PFE group, while Arylsulfatase A and F-actin capping protein subunit alpha 1 were more expressed in the GEF group. Based on their functions and interactions with other proteins, we conclude that these four sperm membrane proteins may act as potential markers of boar semen freezability.

Proteomic characterization of canine seminal plasma

The present study was conducted to identify the major proteome of the sperm-rich fraction and prostatic fraction of canine seminal plasma. Three semen samples from four healthy dogs were obtained by digital manipulation. The pre-sperm fraction, sperm-rich fraction and prostatic fraction were separated from each ejaculate. Immediately after sperm analysis, a protease inhibitor was added to the sperm-rich fraction and prostatic fraction, and the fractions were separately centrifuged and frozen at -80 °C. The samples were thawed, re-centrifuged, and the total protein concentration was determined. Samples were subjected to 1D SDS-PAGE and Coomassie-blue stained gels, were analyzed by Quantity One 1D Analysis Software. Bands detected in the gels were excised and proteins subjected to digestion with trypsin. Proteins were identified by nano-HPLC-MS and tools of bioinformatics. Tandem mass spectrometry allowed the detection of 268 proteins in the gels of sperm-rich fraction and prostatic fraction of canine ejaculate. A total of 251 proteins were common to the sperm-rich and prostatic fractions, while 17 proteins were present in the sperm-rich fraction and absent in the prostatic fraction. The intensity of the bands detected in range 1 and 2 represented 46.5% of all of the band intensities detected in the 1D gels for proteins of the sperm-rich fraction and 53.0% of all bands in the prostatic fraction. Arginine esterase and lactotransferrin precursor were the protein with the highest intensity observed in the both fractions. Among the proteins present only in the sperm-rich fraction, the proteins UPF0764 protein C16orf89 homolog and epididymal-specific lipocalin-9 were the most abundant. In conclusion, canine sperm-rich fraction and prostatic fraction express a very diverse set of proteins, with unique biochemical properties and functions. Moreover, although most proteins are common to both sperm-rich fraction and prostatic fraction, there are some exclusive proteins in sperm-rich fraction.

Purification of binder of sperm protein 1 (BSP1) and its effects on bovine in vitro embryo development after fertilization with ejaculated and epididymal sperm

The present study evaluated functional aspects of binder of sperm 1 (BSP1) in the bovine species. In a first experiment, cumulus-oocyte complexes (n = 1274) were incubated with frozen-thawed ejaculated sperm (18 hours) in Fert-TALP medium containing: heparin, 10, 20, or 40 μg/mL BSP1. Heparin followed by gelatin affinity chromatography was used for purification of BSP1 from bovine seminal vesicle fluid. With ejaculated sperm, cleavage rates were similar when Fert-TALP medium was incubated with heparin (74.1 ± 2.7%), 10 μg/mL BSP1 (77.8 ± 3.1%), or 20 μg/mL BSP1 (74 ± 2.0%). Day-7 blastocyst rates were equivalent after incubations with heparin (40.8 ± 5.0%) and 10 μg/mL BSP1 (34.1 ± 4.4%), but reduced after 20 μg/mL BSP1 (22.4 ± 2.9%) and 40 μg/mL BSP1 (19.3 ± 4.1%; P < 0.05). In the second experiment, cumulus-oocyte complexes (n = 1213) were incubated with frozen-thawed cauda epididymal sperm (18 hours) in Fert-TALP medium containing: no heparin, heparin, 10, 20, or 40 μg/mL. Cleavage and blastocyst rates were similar after treatments with heparin (68.5 ± 1.3% and 24.7 ± 3.2%, respectively) or without heparin (65.5 ± 1.8% and 27.3 ± 1.6%, respectively). Cleavage was higher after treatment with any BSP1 concentrations (74.2 ± 2.7%-79.0 ± 1.1%) than without heparin (P < 0.05). Also, cleavage was better after Fert-TALP medium incubation with 40 μg/mL BSP1 (79.0 ± 1.1%) than with heparin (68.5 ± 1.3%; P < 0.05). Embryo development was higher (P < 0.05) after treatment with 20 μg/mL BSP1 (35.6 ± 2.5%) and 40 μg/mL (41.1 ± 2%) than after incubations with heparin (24.7 ± 3.2%) or without heparin (27.3 ± 1.6%). Interestingly, BSP1 did not cause reductions in blastocyst rates after fertilization with epididymal sperm, as observed with ejaculated sperm. On the basis of immunocytochemistry, there was BSP1 binding to frozen-thawed ejaculated but not to epididymal sperm. Also, anti-BSP1 reaction remained on ejaculated sperm (as expected) and appeared on epididymal sperm after incubation with purified BSP1. Acrosome reaction of ejaculated and epididymal sperm was induced after incubation with purified BSP1 as well, indicating an effect of BSP1 on capacitation. In conclusion, purified BSP1 from bull seminal vesicles was able to bind to and induce capacitation of ejaculated and epididymal sperm. Also, BSP1 added to fertilization media and allowed proper cleavage and embryo development, with the effects being modulated by previous exposure or not of spermatozoa to seminal plasma.

Seminal plasma proteins and their relationship with percentage of morphologically normal sperm in 2-year-old Brahman (Bos indicus) bulls

The objective was to determine the relationship between seminal plasma proteins and sperm morphology in Bos indicus bulls of the Brahman breed. Fifty-six 24-month-old Australian Brahman bulls were electroejaculated and samples were examined to determine the percentage of morphologically normal sperm (PNS24) and the seminal plasma protein composition was identified and quantified by 2-D gel electrophoresis. The total integrated optical density of 152 seminal plasma protein spots (SPPs) across all gels was determined using the PDQuest software version 8.0 (Bio Rad, USA). Using a single regression mixed model with the density of individual spots as a covariate for PNS24, 17 SPPs were significantly associated with PNS24 (p<0.05). A multiple regression analyses of these SPPs, using three models; non-parametric Tree Model, Generalized Additive Model, and a step-wise selection method were conducted, and 6 SPPs could be used to predict PNS24; four SPPs had positive and two had negative association with PNS24. Together these spots explained 35% of the phenotypic variation in PNS24. Using mass spectrometry (MALDI-ToF and TripleToF-MS) the SPPs with positive relationship contained mainly apolipoprotein A-I (1310), protein DJ-1 and glutathione peroxidase 3 (2308), phosphoglycerate kinase 1 (6402) and apolipoprotein A-I and secretoglobin family 1D member (8008). The SPPs inversely associated with PNS24 were clusterin/seminal plasma protein A3 (1411) and epididymal secretory protein E1 (8108). This is the first comprehensive report on the association between seminal plasma protein composition in Bos indicus Brahman bulls and sperm morphology.