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

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.

Candida Genus Maximum Incidence in Boar Semen Even after Preservation, Is It Not a Risk for AI though?

There is little information in the literature about the fungal contamination of boar semen and its persistence during storage. The challenge of this study was to perform a mycological screening to identify the yeast in the raw semen at 12/24 h after dilution. The research was done in pig farms in the N-E area of Romania, with maximum biosecurity and state-of-the-art technology. All the examined ejaculates (101) were considered to be normal for each spermogram parameter, with microbiological determinations in T0 at the time of ejaculate collection, T1 at the time of dilution, and T2 at 24 h of storage. Microbiological determinations (mycological spermogram) were performed for quantitative (LogCFU/mL) and qualitative (typification of fungal genera) identification. Bacterial burden (×103 LogCFU/mL) after dilution (T1) decreased drastically (p < 0.0001) compared to the one in the raw semen (T0). After 24 h of storage at 17 °C, the mean value of the bacteriospermia remained constant at an average value of 0.44. Mycospermia had a constant trend at T0 (raw) and T1 (0.149 vs. 0.140) and was slightly higher at T2 (0.236). The difference between T1 vs. T2 (p = 0.0419) was close to the statistical reference value (p = 0.05). Of the total genera identified (24), the fungi had a proportion of 37.4% (9/15) and a ratio of 1:1.6. Regarding the total species (34), the fungi had a frequency of 29.42% (10/24) with a ratio between the fungi and bacteria of 1:2.4. A fertility rate of 86% was observed in the L1 group (50 AI sows with doses and mycospermia from T1), and an 82% rate was observed in the L2 group (50 AI sows with doses and mycospermia from T2). The litter size of L1 was 9.63 piglets and 9.56 for L2. Regarding the total number of piglets obtained between the two groups, there was a slight decrease of 22 piglets in group L2, without statistical differences (p > 0.05). The predominant genera persisted after dilution during a 12 h storage at 17 °C, where yeasts, such as Candida parapsilosis and C. sake were identified in more than 92% of AI doses.

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.

The characteristics of proteome and metabolome associated with contrasting sperm motility in goat seminal plasma

Sperm motility is an index tightly associated with male fertility. A close relationship between seminal plasma and sperm motility has been confirmed. This study was to assess the protein and metabolite profiles of seminal plasma obtained from adult goats with high or low sperm motility using the proteomic and metabolomic strategies. In total, 2098 proteins were found. 449 differentially abundant proteins (DAPs) were identified, and 175 DAPs were enriched in the high motility group. The obtained DAPs primarily exist in cytoplasma and extra-cellular portion. The Gene Ontology enrichment analysis demonstrated the main functional roles of these DAPs in regulating biological process, metabolic process of organic substances, cellular-metabolic process, primary-metabolic process, metabolic process of nitrogen compounds, etc. Additionally, the Kyoto-Encyclopedia of Genes and Genomes (KEGG) analysis revealed that these DAPs were primarily involved in phosphatidylinositol signaling system, salivary secretion, proteasome, apoptosis, mitophagy-animal, etc. Aided by the parallel reaction monitoring technology, the abundance changing pattern of 19 selected DAPs was consistent with that of the corresponding proteins obtained by TMT. A total of 4603 metabolites were identified in seminal plasma. 1857 differential metabolites were found between the high motility group and the low motility group, and 999 metabolites were up-regulated in the high motility group. The KEGG analysis demonstrated the primary involvement of the differential metabolites in metabolic and synthetic activities. In conclusion, we first established the proteome and metabolome databank of goat seminal plasma, detecting some proteins and metabolites which may affect sperm motility. This study will be valuable for understanding mechanisms leading to poor sperm motility.

Deactivation of the JNK Pathway by GSTP1 Is Essential to Maintain Sperm Functionality

Fifty percent of male subfertility diagnosis is idiopathic and is usually associated with genetic abnormalities or protein dysfunction, which are not detectable through the conventional spermiogram. Glutathione S-transferases (GSTs) are antioxidant enzymes essential for preserving sperm function and maintaining fertilizing ability. However, while the role of GSTP1 in cell signaling regulation via the inhibition of c-Jun N-terminal kinases (JNK) has been enlightened in somatic cells, it has never been investigated in mammalian spermatozoa. In this regard, a comprehensive approach through immunoblotting, immunofluorescence, computer-assisted sperm assessment (CASA), and flow cytometry analysis was used to characterize the molecular role of the GSTP1–JNK heterocomplex in sperm physiology, using the pig as a model. Immunological assessments confirmed the presence and localization of GSTP1 in sperm cells. The pharmacological dissociation of the GSTP1–JNK heterocomplex resulted in the activation of JNK, which led to a significant decrease in sperm viability, motility, mitochondrial activity, and plasma membrane stability, as well as to an increase of intracellular superoxides. No effects in intracellular calcium levels and acrosome membrane integrity were observed. In conclusion, the present work has demonstrated, for the first time, the essential role of GSTP1 in deactivating JNK, which is crucial to maintain sperm function and has also set the grounds to understand the relevance of the GSTP1–JNK heterocomplex for the regulation of mammalian sperm physiology.

Antibacterial defense in bull and boar semen: A putative link to the microbiome and reproductive strategy?

Several domestic and wildlife species have been shown to possess antibacterial defenses in their ejaculate most probably in order to increase the fertilization success and protect against sexually transmitted pathogens. However, very little is known about the consequences and factors influencing the differences within and between species as far as ejaculate-associated immunity. In the present study, we have analyzed bacterial killing activity (BKA) against Escherichia (E.) coli and Staphylococcus (S.) aureus as well as lysozyme concentrations (LC) in seminal plasma from 60 Fleckvieh bulls. Further, sperm quality and its association with BKA and LC were determined. Twenty percent of the individuals displayed BKA against both bacteria, 78.3% against S. aureus only and 1.7% of the bulls did not indicate any BKA in seminal plasma. No bulls with seminal plasma BKA only against E. coli were identified; implying that 80.0% of the tested bulls had no ejaculate associated defense mechanisms against this gram-negative bacterial species in place. This is in striking contrast to results of Pietrain boars within our previous study, in which 42.8% of the 119 boars expressed an antibacterial activity against E. coli in seminal plasma, 10.9% amongst them with BKA against E. coli only. LC was higher in the bull group with BKA against both bacteria (1.2 ± 0.6 μg/mL) compared to the group with BKA against S. aureus only (0.7 ± 0.3 μg/mL), but - if calculated over all individuals - LC in bulls (0.8 ± 0.4 μg/mL) was lower compared to boars (2.4 ± 1.2 μg/mL). LC showed positive correlations to the age of the bulls and sperm quality as well as a negative relation to bacterial load in raw semen although the highest bacterial contamination was found in animals with seminal plasma BKA against both strains. We discuss the obtained results with regards to possible differences within the microbiome of female and male genital tracts and the reproductive strategies (vaginal vs. uterine depositors) in these two livestock species. Besides identifying the responsible molecules, future phylogenetically controlled comparative studies are needed for a better understanding of the evolution of species differences in ejaculate-associated antibacterial defenses.

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).