A comprehensive N-glycome map of porcine sperm membrane before and after capacitation.

Mapping the N-glycome of porcine sperm before and after sperm capacitation is important for understanding the rearrangement of glycoconjugates during capacitation. In this work, we characterized the N-glycome on the membranes of 18 pairs of fresh porcine sperm before capacitation and porcine sperm after capacitation by MALDI-MS (Matrix-assisted laser desorption/ionization-mass spectrometry). A total of 377 N-glycans were detected and a comprehensive N-glycome map of porcine sperm membranes before and after capacitation was generated, which presents the largest N-glycome dataset of porcine sperm cell membranes. Statistical analysis revealed a significantly higher level of high mannose glycosylation and a significantly lower level of fucosylation, galactosylation, and α-2,6-NeuAc after capacitation, which is further verified by flow cytometry and lectin blotting. This research reveals new insights into the relationship between N-glycosylation variations and sperm capacitation, including the underlying mechanisms of the capacitation process.

Characterization of a novel fast-growing zebrafish: a new approach to growth hormone transgenesis.

The manipulation of the somatotropic axis, governing growth, has been a focus of numerous transgenic approaches aimed at developing fast-growing fish for research, medicine and aquaculture purposes. However, the excessively high growth hormone (GH) levels in these transgenic fish often result in deformities that impact both fish health and consumer acceptance. In an effort to mitigate these issues and synchronize exogenous GH expression with reproductive processes, we employed a novel transgenic construct driven by a tilapia luteinizing hormone (LH) promoter. This approach was anticipated to induce more localized and lower exogenous GH secretion. In this study, we characterized the growth and reproduction of these transgenic LHp-GH zebrafish using hormonal and physiological parameters. Our findings reveal that LHp-GH fish exhibited accelerated growth in both length and weight, along with a lower feed conversion ratio, indicating more efficient feed utilization, all while maintaining unchanged body proportions. These fish demonstrated higher expression levels of LH and GH in the pituitary and elevated IGF-1 levels in the liver compared to wild-type fish. An examination of reproductive function in LHp-GH fish unveiled lower pituitary LH and FSH contents, smaller follicle diameter in female gonads, and reduced relative fecundity. However, in transgenic males, neither the distribution of spermatogenesis stages nor sperm concentrations differed significantly between the fish lines. These results suggest that coupling exogenous GH expression with endogenous LH expression in females directs resource investment toward somatic growth at the expense of reproductive processes. Consequently, we conclude that incorporating GH under the LH promoter represents a suitable construct for the genetic engineering of commercial fish species, providing accelerated growth while preserving body proportions.

SMA20/PMIS2 Is a Rapidly Evolving Sperm Membrane Alloantigen with Possible Species-Divergent Function in Fertilization.

Immunodominant alloantigens in pig sperm membranes include 15 known gene products and a previously undiscovered Mr 20,000 sperm membrane-specific protein (SMA20). Here we characterize SMA20 and identify it as the unannotated pig ortholog of PMIS2. A composite SMA20 cDNA encoded a 126 amino acid polypeptide comprising two predicted transmembrane segments and an N-terminal alanine- and proline (AP)-rich region with no apparent signal peptide. The Northern blots showed that the composite SMA20 cDNA was derived from a 1.1 kb testis-specific transcript. A BLASTp search retrieved no SMA20 match from the pig genome, but it did retrieve a 99% match to the Pmis2 gene product in warthog. Sequence identity to predicted PMIS2 orthologs from other placental mammals ranged from no more than 80% overall in Cetartiodactyla to less than 60% in Primates, with the AP-rich region showing the highest divergence, including, in the extreme, its absence in most rodents, including the mouse. SMA20 immunoreactivity localized to the acrosome/apical head of methanol-fixed boar spermatozoa but not live, motile cells. Ultrastructurally, the SMA20 AP-rich domain immunolocalized to the inner leaflet of the plasma membrane, the outer acrosomal membrane, and the acrosomal contents of ejaculated spermatozoa. Gene name search failed to retrieve annotated Pmis2 from most mammalian genomes. Nevertheless, individual pairwise interrogation of loci spanning Atp4a-Haus5 identified Pmis2 in all placental mammals, but not in marsupials or monotremes. We conclude that the gene encoding sperm-specific SMA20/PMIS2 arose de novo in Eutheria after divergence from Metatheria, whereupon rapid molecular evolution likely drove the acquisition of a species-divergent function unique to fertilization in placental mammals.

Mitochondrial Differentiation during Spermatogenesis: Lessons from Drosophila melanogaster.

Numerous diseases can arise as a consequence of mitochondrial malfunction. Hence, there is a significant focus on studying the role of mitochondria in cancer, ageing, neurodegenerative diseases, and the field of developmental biology. Mitochondria could exist as discrete organelles in the cell; however, they have the ability to fuse, resulting in the formation of interconnected reticular structures. The dynamic changes between these forms correlate with mitochondrial function and mitochondrial health, and consequently, there is a significant scientific interest in uncovering the specific molecular constituents that govern these transitions. Moreover, the specialized mitochondria display a wide array of variable morphologies in their cristae formations. These inner mitochondrial structures are closely associated with the specific functions performed by the mitochondria. In multiple cases, the presence of mitochondrial dysfunction has been linked to male sterility, as it has been observed to cause a range of abnormal spermatogenesis and sperm phenotypes in different species. This review aims to elucidate the dynamic alterations and functions of mitochondria in germ cell development during the spermatogenesis of Drosophila melanogaster.

Kaempferol as an Alternative Cryosupplement for Bovine Spermatozoa: Cytoprotective and Membrane-Stabilizing Effects.

Kaempferol (KAE) is a natural flavonoid with powerful reactive oxygen species (ROS) scavenging properties and beneficial effects on ex vivo sperm functionality. In this paper, we studied the ability of KAE to prevent or ameliorate structural, functional or oxidative damage to frozen-thawed bovine spermatozoa. The analysis focused on conventional sperm quality characteristics prior to or following thermoresistance tests, namely the oxidative profile of semen alongside sperm capacitation patterns, and the levels of key proteins involved in capacitation signaling. Semen samples obtained from 30 stud bulls were frozen in the presence of 12.5, 25 or 50 µM KAE and compared to native ejaculates (negative control-CtrlN) as well as semen samples cryopreserved in the absence of KAE (positive control-CtrlC). A significant post-thermoresistance test maintenance of the sperm motility (p < 0.001), membrane (p < 0.001) and acrosome integrity (p < 0.001), mitochondrial activity (p < 0.001) and DNA integrity (p < 0.001) was observed following supplementation with all KAE doses in comparison to CtrlC. Experimental groups supplemented with all KAE doses presented a significantly lower proportion of prematurely capacitated spermatozoa (p < 0.001) when compared with CtrlC. A significant decrease in the levels of the superoxide radical was recorded following administration of 12.5 (p < 0.05) and 25 µM KAE (p < 0.01). At the same time, supplementation with 25 µM KAE in the cryopreservation medium led to a significant stabilization of the activity of Mg2+-ATPase (p < 0.05) and Na+/K+-ATPase (p < 0.0001) in comparison to CtrlC. Western blot analysis revealed that supplementation with 25 µM KAE in the cryopreservation medium prevented the loss of the protein kinase A (PKA) and protein kinase C (PKC), which are intricately involved in the process of sperm activation. In conclusion, we may speculate that KAE is particularly efficient in the protection of sperm metabolism during the cryopreservation process through its ability to promote energy synthesis while quenching excessive ROS and to protect enzymes involved in the process of sperm capacitation and hyperactivation. These properties may provide supplementary protection to spermatozoa undergoing the freeze-thaw process.

Insights on Platelet-Derived Growth Factor Receptor α-Positive Interstitial Cells in the Male Reproductive Tract.

Male infertility is a significant factor in approximately half of all infertility cases and is marked by a decreased sperm count and motility. A decreased sperm count is caused by not only a decreased production of sperm but also decreased numbers successfully passing through the male reproductive tract. Smooth muscle movement may play an important role in sperm transport in the male reproductive tract; thus, understanding the mechanism of this movement is necessary to elucidate the cause of sperm transport disorder. Recent studies have highlighted the presence of platelet-derived growth factor receptor α (PDGFRα)-positive interstitial cells (PICs) in various smooth muscle organs. Although research is ongoing, PICs in the male reproductive tract may be involved in the regulation of smooth muscle movement, as they are in other smooth muscle organs. This review summarizes the findings to date on PICs in male reproductive organs. Further exploration of the structural, functional, and molecular characteristics of PICs could provide valuable insights into the pathogenesis of male infertility and potentially lead to new therapeutic approaches.

A Pilot Analysis of Whole Transcriptome of Human Cryopreserved Sperm.

Sperm cryopreservation is a procedure widely used to store gametes for later use, to preserve fertility in patients prior to gonadotoxic treatments or surgery, and for sperm donation programs. The purpose of the study was to assess the impact of cryopreservation on human sperm transcriptome. Semen samples were collected from 13 normospermic men. Each sample was divided into two aliquots. The total RNA was immediately extracted from one aliquot. The second aliquot was frozen and total RNA was extracted after a week of storage in liquid nitrogen. The RNA samples were randomized in four pools, each of six donors, and analyzed by microarrays. The paired Significance Analysis of Microarray was performed. We found 219 lower abundant transcripts and 28 higher abundant transcripts in cryopreserved sperm than fresh sperm. The gene ontology analysis disclosed that cryopreservation alters transcripts of pathways important for fertility (i.e., spermatogenesis, sperm motility, mitochondria function, fertilization, calcium homeostasis, cell differentiation, and early embryo development), although the increase of some transcripts involved in immune response can compensate for the harmful effects of freezing.

Hypoxia enhances autophagy level of human sperms.

The relationship between oxygen sensing and autophagy in human sperms was explored in this study. Health semen and asthenozoospermia (astheno) semen were incubated with hypoxia-inducible factor-1α (HIF-1α) interferents, i.e., lificiguat (YC-1) or cobalt chloride (CoCl2), respectively. Label-free quantitative proteomic technology was used to identify the differentially expressed proteins in human semen under the hypoxia condition. Selected proteins were detected with ELISA. It was found that the autophagy levels of sperm in the YC-1 + health group or CoCl2 + astheno group increased while the vitality decreased. A total of 17, 34 and 35 differentially expressed proteins were observed in the Astheno group, the YC-1 + health group and the CoCl2 + astheno group, respectively. These proteins were primarily associated with protein processing in endoplasmic reticulum, Th17 cell differentiation, progesterone-mediated oocyte maturation, glycolysis/gluconeogenesis, HIF-1 signaling pathway, biosynthesis of amino acids, and carbon metabolism. The expression levels of protein HIF-1α, LC3B, histone H4, cathepsin L and ENO1 changed significantly in the groups. The study suggests that hypoxia can increase sperm autophagy level and reduce their vitality through HIF-1 signaling pathway and glycolysis/gluconeogenesis signaling pathway. Furthermore, proteins histone H4, cathepsin L, glutathione synthetase and ENO1 are proposed as potential biomarkers of autophagy and vitality in asthenozoospermia sperm.

Nuclear autoantigenic sperm protein facilitates glioblastoma progression and radioresistance by regulating the ANXA2/STAT3 axis.

AIMS: Although radiotherapy is a core treatment modality for various human cancers, including glioblastoma multiforme (GBM), its clinical effects are often limited by radioresistance. The specific molecular mechanisms underlying radioresistance are largely unknown, and the reduction of radioresistance is an unresolved challenge in GBM research. METHODS: We analyzed and verified the expression of nuclear autoantigenic sperm protein (NASP) in gliomas and its relationship with patient prognosis. We also explored the function of NASP in GBM cell lines. We performed further mechanistic experiments to investigate the mechanisms by which NASP facilitates GBM progression and radioresistance. An intracranial mouse model was used to verify the effectiveness of combination therapy. RESULTS: NASP was highly expressed in gliomas, and its expression was negatively correlated with the prognosis of glioma. Functionally, NASP facilitated GBM cell proliferation, migration, invasion, and radioresistance. Mechanistically, NASP interacted directly with annexin A2 (ANXA2) and promoted its nuclear localization, which may have been mediated by phospho-annexin A2 (Tyr23). The NASP/ANXA2 axis was involved in DNA damage repair after radiotherapy, which explains the radioresistance of GBM cells that highly express NASP. NASP overexpression significantly activated the signal transducer and activator of transcription 3 (STAT3) signaling pathway. The combination of WP1066 (a STAT3 pathway inhibitor) and radiotherapy significantly inhibited GBM growth in vitro and in vivo. CONCLUSION: Our findings indicate that NASP may serve as a potential biomarker of GBM radioresistance and has important implications for improving clinical radiotherapy.

The Clinical Investigation on Varicocele and Sperm Quality in the Tibet an Plateau of China: A Prospectively Planned Retrospective Cohort Study.

Varicoceles are a common cause of male infertility, affecting up to 35% of men undergoing fertility evaluations. This study aims to investigate the potential influence of altitude and residence time on the occurrence of varicoceles, as well as on sperm quality and sterility in plateau areas. A total of 168 patients with varicocele were enrolled in the study, and the study population was divided into groups based on their direct exposure to different high altitudes due to their living locations. The internal diameter in Quiet breath (Dr), internal diameter in Valsalva maneuver (Dv), reflux peak value, and reflux time are gradually increased accompanied with altitude elevation and residence time extension. The number of cases above 4,500 m also increased with the severity of varicocele, and the altitude of clinical types was higher than that of subclinical types of varicocele. Especially above 4,500 m, the Dv, Dr, reflux peak value, and reflux time all increased with the severity of varicocele. The severity of varicocele was positively correlated with the residence time in plateau area. Patients with residence time of more than 1 year had higher values of Dr, Dv, differentiation time, reflux peak value, and reflux time than those with residence time of less than 1 year. Compared to 3,650 m, patients with varicocele in 4,500 m also have worse semen quality. Both altitude and residence time are strongly positively related to the severity and incidence rate of varicocele in plateau areas.

A Single-Cell Landscape of Spermioteleosis in Mice and Pigs.

(1) Background: Spermatozoa acquired motility and matured in epididymis after production in the testis. However, there is still limited understanding of the specific characteristics of sperm development across different species. In this study, we employed a comprehensive approach to analyze cell compositions in both testicular and epididymal tissues, providing valuable insights into the changes occurring during meiosis and spermiogenesis in mouse and pig models. Additionally, we identified distinct gene expression signatures associated with various spermatogenic cell types. (2) Methods: To investigate the differences in spermatogenesis between mice and pigs, we constructed a single-cell RNA dataset. (3) Results: Our findings revealed notable differences in testicular cell clusters between these two species. Furthermore, distinct gene expression patterns were observed among epithelial cells from different regions of the epididymis. Interestingly, regional gene expression patterns were also identified within principal cell clusters of the mouse epididymis. Moreover, through analysing differentially expressed genes related to the epididymis in both mouse and pig models, we successfully identified potential marker genes associated with sperm development and maturation for each species studied. (4) Conclusions: This research presented a comprehensive single-cell landscape analysis of both testicular and epididymal tissues, shedding light on the intricate processes involved in spermatogenesis and sperm maturation, specifically within mouse and pig models.

Consequences of Exposure to Hypobaric Hypoxia Associated with High Altitude on Spermatogenesis and Seminal Parameters: A Literature Review.

Preclinical research has provided compelling evidence indicating that exposure to hypobaric hypoxia (HH) results in a deterioration of spermatogenesis. This adverse effect extends to the underlying molecular mechanisms, progressively leading to impairments in the seminiferous epithelium and germ cells and alterations in semen parameters. Indeed, several studies have demonstrated that animals exposed to HH, whether in natural high-altitude environments or under simulated hypoxic conditions, exhibit damage to the self-renewal and differentiation of spermatogenesis, an increase in germline cell apoptosis, and structural alterations in the seminiferous tubules. One of the primary mechanisms associated with the inhibition of differentiation and an increase in apoptosis among germ cells is an elevated level of oxidative stress, which has been closely associated with HH exposure. Human studies have shown that individuals exposed to HH, such as mountaineers and alpinists, exhibit decreased sperm count, reduced motility, diminished viability, and increased sperm with abnormal morphology in their semen. This evidence strongly suggests that exposure to HH may be considered a significant risk factor that could elevate the prevalence of male infertility. This literature review aims to provide a comprehensive description and propose potential mechanisms that could elucidate the infertility processes induced by HH. By doing so, it contributes to expanding our understanding of the challenges posed by extreme environments on human physiology, opening new avenues for research in this field.

Paternal Age Amplifies Cryopreservation-Induced Stress in Human Spermatozoa.

The global fall in male fertility is a complicated process driven by a variety of factors, including environmental exposure, lifestyle, obesity, stress, and aging. The availability of assisted reproductive technology (ART) has allowed older couples to conceive, increasing the average paternal age at first childbirth. Advanced paternal age (APA), most often considered male age ≥40, has been described to impact several aspects of male reproductive physiology. In this prospective cohort study including 200 normozoospermic patients, 105 of whom were ≤35 years (non-APA), and 95 of whom were ≥42 years (APA), we assessed the impact of paternal age on different endpoints representative of sperm quality and cryopreservation tolerance. Non-APA patients had superior fresh semen quality; DNA fragmentation was notably increased in APA as compared to non-APA individuals (21.7% vs. 15.4%). Cryopreservation further increased the DNA fragmentation index in APA (26.7%) but not in non-APA patients. Additionally, APA was associated with increased mtDNAcn in both fresh and frozen/thawed sperm, which is indicative of poorer mitochondrial quality. Cryopreservation negatively impacted acrosome integrity in both age groups, as indicated by reduced incidences of unreacted acrosome in relation to fresh counterparts in non-APA (from 71.5% to 57.7%) and APA patients (from 75% to 63%). Finally, cryopreservation significantly reduced the phosphorylation status of proteins containing tyrosine residues in sperm from young males. Therefore, the present findings shed light on the effects of paternal age and cryopreservation on sperm quality and serve as valuable new parameters to improve our understanding of the mechanisms underlying sperm developmental competence that are under threat in current ART practice.

The journey of a generation: advances and promises in the study of primordial germ cell migration.

The germline provides the genetic and non-genetic information that passes from one generation to the next. Given this important role in species propagation, egg and sperm precursors, called primordial germ cells (PGCs), are one of the first cell types specified during embryogenesis. In fact, PGCs form well before the bipotential somatic gonad is specified. This common feature of germline development necessitates that PGCs migrate through many tissues to reach the somatic gonad. During their journey, PGCs must respond to select environmental cues while ignoring others in a dynamically developing embryo. The complex multi-tissue, combinatorial nature of PGC migration is an excellent model for understanding how cells navigate complex environments in vivo. Here, we discuss recent findings on the migratory path, the somatic cells that shepherd PGCs, the guidance cues somatic cells provide, and the PGC response to these cues to reach the gonad and establish the germline pool for future generations. We end by discussing the fate of wayward PGCs that fail to reach the gonad in diverse species. Collectively, this field is poised to yield important insights into emerging reproductive technologies.

Dual-Activated H2O2-Responsive AIE Probes for Oocyte Quality Assessment.

Nonobstructive azoospermia (NOA) is an important cause of infertility, and intracytoplasmic sperm injection (ICSI) is the mainstay of treatment for these patients. In cases where a sufficient number of sperm (usually 1-2) is not available, the selection of oocytes for ICSI is a difficult problem that must be solved. Here, we constructed a dual-activated oxidative stress-responsive AIE probe, b-PyTPA. The strong donor-acceptor configuration of b-PyTPA leads to twisted intramolecular charge transfer (TICT) effect that quenches the fluorescence of the probe, however, H2O2 would specifically remove the boronatebenzyl unit and release a much weaker acceptor, which inhibits TICT and restores the fluorescence. In addition, the presence of a pyridine salt makes b-PyTPA more hydrophilic, whereas removal of the pyridine salt increases the hydrophobicity of PyTPA, which triggers aggregation and further enhances fluorescence. Thus, the higher the intracellular level of oxidative stress, the stronger the fluorescence. In vitro, this dual-activated fluorescent probe is capable of accurately detecting senescent cells (high oxidative stress). More importantly, b-PyTPA was able to characterize senescent oocytes, as assessed by the level of oxidative stress. It is also possible to identify high quality oocytes from those obtained for subsequent ICSI. In conclusion, this dual-activated oxidative stress-assessment probe enables the quality assessment of oocytes and has potential application in ICSI.

[Effect and mechanism of aqueous extract of Strychni Semen on bone destruction in rats with type â ¡ collagen-induced rheumatoid arthritis].

To investigate the mechanism of action of aqueous extract of Strychni Semen(SA) on bone destruction in rats with type Ⅱ collagen-induced arthritis(CIA), the SD rats were randomly divided into normal group, model group, low, medium, and high dose(2.85, 5.70, and 11.40 mg·kg~(-1)) groups of SA, and methotrexate group. Except for the normal group, the CIA model was prepared for the other groups. After the second immunization, different doses of SA were given to the low, medium, and high dose groups of SA once a day, and the methotrexate group was given once every three days. 0.3% sodium hydroxymethylcellulose(CMC-Na) was given once a day to the normal and model groups for 28 d. The clinical score of arthritis was evaluated every three days. Micro computed tomography(Micro-CT) method was used to evaluate the degree of bone destruction. Histopathological changes in the joint tissue and the number of osteoclasts in CIA rats were evaluated by hematoxylin-eosin(HE) staining and tartrate-resistant acid phosphatase(TRAP) staining. The expression of interleukin-1ß(IL-1ß) in the joint tissue of rats was detected by immunohistochemistry. Western blot was used to detect key protein expression in mitogen-activated protein kinase(MAPK) and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt) signaling pathways in the joint tissue of rats. The results showed that different doses of SA were able to improve the red and swollen inflammatory joint and joint deformity in CIA rats to varying degrees, reduce the clinical score, inhibit synovial inflammation, vascular opacification, cartilage erosion, and bone destruction, and reduce the number of TRAP-positive cells in bone tissue. Micro-CT results showed that the SA was able to increase bone mineral density, bone volume fraction, trabecular reduce, and trabecular number and reduce bone surface/bone volume and trabecular separation/spacing. Different doses of SA could down-regulate the protein expression of IL-1ß, p-JNK, p-ERK, p-p38, PI3K, and p-Akt to varying degrees. In conclusion, SA can improve disease severity, attenuate histopathological and imaging changes in joints, and have osteoprotective effects in CIA rats, and its mechanism of action may be related to the inhibition of the overactivation of MAPK and PI3K/Akt signaling pathways.

[Mechanism of aqueous extract of Strychni Semen in improving pain in rats with rheumatoid arthritis based on TLR4/TNF-α/MMP-9 signaling pathway].

This study aims to explore the mechanism of aqueous extract of Strychni Semen(SA) in relieving pain in the rat model of rheumatoid arthritis(RA) via Toll-like receptor 4(TLR4)/tumor necrosis factor-α(TNF-α)/matrix metalloproteinase-9(MMP-9) signaling pathway. Firstly, the main chemical components of Strychni Semen were searched against TCMSP, TCMID, ETCM, and related literature, and the main targets of the chemical components were retrieved from TargetNet and SwissTargetPrediction. The main targets of RA and pain were searched against GeneCards, Online Mendelian Inheritance in Man(OMIM), and Therapeutic Target Database(TTD). Venny 2.1.0 was used to obtain the common targets shared by Strychni Semen, RA, and pain, and STRING and Cytoscape 3.6.1 were used to build the protein-protein interaction network. Then, molecular docking was carried out in AutoDock Vina. Finally, the rat model of type Ⅱ collagen-induced arthritis(CIA) was established. The up-down method and acetone method were employed to examine the mechanical pain threshold and cold pain threshold of rats, and the pain-relieving effect of SA on CIA rats was evaluated comprehensively. Hematoxylin-eosin(HE) staining was employed to evaluate the histopathological changes of joints in CIA rats. The expression levels of key target proteins was determined by immunohistochemistry and Western blot, and the mRNA levels of key targets were determined by real-time fluorescence quantitative polymerase chain reaction(real-time PCR). The results of network prediction showed that Strychni Semen may act on the TLR4/TNF-α/MMP-9 signaling pathway to exert the pain-relieving effect. The results of molecular docking showed that brucine, the main active component of SA, had strong binding ability to TLR4, TNF-α, and MMP-9. The results of animal experiments showed that SA improved the mechanical and cold pain sensitivity(P<0.05, P<0.01) and reduced the joint histopathological score of CIA rats(P<0.01). In addition, medium and high doses of SA down-regulated the protein and mRNA levels of TNF-α, TLR4, and MMP-9(P<0.05,P<0.01). In conclusion, SA alleviated the mechanical pain sensitivity, cold pain sensitivity, and joint histopathological changes in CIA rats by inhibiting the over activation of TLR4/TNF-α/MMP-9 signaling pathway.

Predicting the cryotolerance of boar sperm through antioxidant stress.

High sperm cryotolerance is crucial to the successful cryopreservation of boar sperm. Evaluating the cryotolerance of boar sperm by using a rapid and convenient technique can enhance the commercial viability of these sperm. This study investigated the correlation between sperm parameters for three sample subsets-fresh sperm, sperm with H2O2-induced oxidative damage (hereinafter referred to as H2O2-induced sperm), and frozen-thawed sperm-to identify the potential of these correlations to predict cryotolerance. A total of 64 sperm samples were obtained from 64 Duroc boars. The sperm parameters of the three subsets, where the frozen-thawed sperm were analysed at 30 or 180 min after thawing, were determined, and the coefficients of correlation between these parameters were calculated. The results indicated that H2O2-induced oxidative stress resulted in decreases in various sperm parameters-including total motility (TM), viability (VIA), mitochondrial membrane potential (MMP), and live sperm with MMP (LMP)-but increased their coefficients of variation. Receiver operating characteristic (ROC) curve analysis revealed that the kinematic parameters of the H2O2-induced sperm effectively predicted those of the frozen-thawed boar sperm at 30 min after thawing; the corresponding area under the ROC curve (AUC) was 0.8667 for TM and 0.8733 for progressive motility in the H2O2-induced sperm. For measurement at 180 min after thawing, the sperm membrane and mitochondrial parameters of the H2O2-induced sperm effectively predicted the LMP of the frozen-thawed boar sperm; the corresponding AUC was 0.8489 for VIA, 0.8289 for MMP, and 0.8444 for LMP. To our knowledge, this is the first study to directly establish a strong correlation between post-thaw boar sperm quality and H2O2-induced oxidative stress before freezing. Our proposed technique can serve as a valuable reference for the development of practical applications aimed at enhancing techniques for cryopreserving boar sperm.

Use of thermography in the long-term evaluation of scrotal surface temperature and its impact on seminal quality in stallions.

Scrotal surface thermography is a non-invasive method for assessing testicular thermoregulation in stallions; however, few studies have explored the application of this technique concerning the thermal physiology of equine reproductive systems. This study aimed to evaluate the consistency of testicular thermoregulation in stallions over a year using thermography to measure the scrotal surface temperature (SST). Moreover, we assessed the best region for measuring the surface body temperature compared with the SST. Ten light-breed stallions were used in the experiment. Thermographic images of the scrotal and body surfaces (neck and abdomen) were captured. Fresh, cooled and frozen-thawed semen samples were evaluated to verify the impact of thermoregulation on semen quality. Testicular thermoregulation was maintained throughout the year in stallions amidst changes in the external temperature, as evidenced by the weak correlation between the SST and ambient temperature. A lower correlation was observed between the environmental temperature and body surface temperature (BTS) obtained from the abdomen (BTS-A; R = .4772; p < .0001) than with that obtained from the neck (BTS-N; R = .7259; p < .0001). Moreover, both BTS-A and SST were simultaneously captured in a single image. The consistent quality of the fresh, cooled and frozen semen suggests efficient thermoregulation in stallions throughout the year.

Optimizing semen cryopreservation in Calomys laucha: a step forward in rodent reproductive research.

BACKGROUND: Examining semen cryopreservation in Calomys laucha offers valuable insights for reproductive research and species conservation. OBJECTIVE: To determine the most effective sugar for the cryopreservation of C. laucha semen. MATERIALS AND METHODS: Using 36 epididymides from C. laucha, semen samples were diluted in a 3% skimmed milk medium supplemented with one of four sugars (glucose, fructose, lactose, or sucrose) at a concentration of 0.3 M. These mixtures underwent a conditioning phase at 37 degree C for 10 min, cooled to -80 degree C for another 10 min, and were subsequently stored in liquid nitrogen. RESULTS: Upon thawing, samples treated with lactose and glucose solutions show superior sperm motility, achieving 8.2% and 10.0% respectively, in contrast to the fructose (2.0%) and sucrose (4.1%) mixtures. Furthermore, samples preserved in glucose registered the highest sperm penetration rates, reaching 44.9%. CONCLUSION: Our findings suggest that a cryopreservation medium containing 0.3 M glucose can contribute to the safeguarding C. laucha rodent semen. https://doi.org/10.54680/fr24210110612.