Search Results (2,772)

Advances in artificial intelligence (AI) are transforming assisted reproductive technologies by significantly enhancing fertility diagnostics. This review focuses on integrating AI with Computer-Aided Sperm Analysis (CASA) systems to improve assessments of sperm motility, morphology, and DNA integrity. By employing a spectrum of techniques, from classic machine learning (ML), often valued for its interpretability and efficiency with structured data, to deep learning (DL), which excels at extracting intricate features directly from image and video data, the field now achieves more accurate, automated, and high-throughput evaluations. These advanced systems offer significant advantages, including enhanced objectivity, improved consistency over manual methods, and the ability to detect subtle predictive patterns not discernible by human observation. The emergence of extensive open datasets and big data analytics has enabled the development of more robust models. However, limitations persist, such as the dependency on large, high-quality annotated datasets for training DL models, potential challenges in model generalizability across diverse clinical settings, and the “black-box” nature of some complex algorithms, alongside crucial needs for rigorous clinical validation, data standardization, and ethical management of sensitive information. Despite promising progress, these challenges must be addressed. Overall, this review outlines current innovations and future research directions essential for advancing personalized, efficient, and accessible fertility care. Full article

The Chinese tongue sole (Cynoglossus semilaevis) is a commercially important mariculture species; however, its fertilization and hatching rates under artificial conditions remain relatively low. Zona pellucida proteins (ZPs), which mediate sperm–egg binding, were previously identified as differentially expressed genes between newly differentiated ovaries and testes in C. semilaevis. In this study, we identified 25 ZPs of C. semilaevis through genomic analysis and classified them into five subfamilies. All genes possessed a conserved ZP domain, characteristic of the gene family from mammals to teleosts. Among them, nine genes were highly expressed in ovary cells, with the expression levels increasing during ovarian development, while another three genes were predominantly expressed in liver cells. Protein–protein interaction analysis predicted that 12 ZPs interacted with key reproductive regulators such as Gdf9, Arid4a, Arid4b, and Rbl, which were involved in steroidogenesis, sperm–egg recognition, and folliculogenesis. Functional analyses using RNA interference revealed that Cszpc7-1 knockdown in ovarian cells led to the downregulation of cyp19a, esr2, bmp15, and adamts-1, while the expression of rbl, gnas, adgrl1, and adgrl2 was upregulated. In contrast, Cszpax1 knockdown resulted in decreased expression of cyp19a, foxl2, arid4a, and zeb1, along with upregulation of arid4b, ogg1, and gdf9. These results suggested that ZP genes might contribute to ovarian homeostasis by regulating steroid hormone synthesis, follicular development, and ovulation. This study contributed to a deeper understanding of the reproductive mechanisms of C. semilaevis and provided evolutionary insights into the functional divergence of the ZP gene family across teleosts. Full article

Purpose: Non-obstructive azoospermia (NOA) presents major challenges in assisted reproductive technology (ART) due to the extremely low number of viable sperm within testicular tissue. In Micro-TESE procedures, embryologists manually search for sperm under DIC microscopy—a slow, labor-intensive process. We aim to streamline this process with an efficient computational detection tool. Methods: We present SD-CLIP (Sperm Detection using Classical Image Processing), a lightweight, real-time algorithm that simulates sperm structure detection from unstained DIC images. The model first identifies convex sperm head candidates based on shape and width using edge gradients, then confirms the presence of a tail via principal component analysis (PCA) of pixel clusters. Results: Compared to the MB-LBP + AKAZE method, SD-CLIP improved processing speed by 4× and achieved a 3.8× higher posterior probability ratio, making detected sperm candidates significantly more reliable. Evaluation was performed on both human Micro-TESE and mouse testis images, demonstrating robustness in low-sperm environments. Conclusions: SD-CLIP simulates a domain-specific image interpretation model that identifies sperm morphology with high specificity. It requires minimal computational resources, supports real-time integration, and could be extended to automated sperm extraction systems. This tool has clinical value for accelerating Micro-TESE and increasing success rates in ART for NOA patients. Full article

Oxidative stress (OS) contributes to poor sperm parameters and increased sperm DNA fragmentation (sDF), yet effective therapeutic strategies remain limited. This study aimed to evaluate the in vitro efficacy of pentoxifylline (PTX) in improving sperm motility and reducing OS and sDF in men with isolated asthenozoospermia. Thirty semen samples from patients with asthenozoospermia were processed using density gradient centrifugation. Each sample was divided into two aliquots: one treated with PTX at a dose of 3.6 mM and the other without PTX treatment. The sperm viability and motility were assessed at 30 min, 1 h, 2 h, and 24 h post-treatment. OS was evaluated using nitro blue tetrazolium staining and a chemiluminescence assay. sDF was assessed using the alkaline Comet assay. The sperm samples treated with PTX, compared to the controls, exhibited a significant increase in total sperm motility (71.8 ± 23.03% versus 47.47 ± 4.88%, respectively; p < 0.0001). However, no significant difference was observed in the sperm viability. PTX treatment significantly reduced ROS production and sDF levels compared to controls (p < 0.01). These findings suggest that in vitro PTX supplementation enhances sperm motility and reduces the nuclear sperm injury associated with seminal ROS production. Therefore, PTX supplementation in vitro may be beneficial in assisted reproductive technology procedures involving men with asthenozoospermia. Full article

Male fertility is strongly influenced by environmental exposures, lifestyle, and advancing age. While advanced paternal age (APA) has been linked with a progressive decline in male fertility, poor reproductive outcomes, and decreased offspring health, the molecular mechanisms underlying these alterations remain unclear. In this work, we investigated the impact of men’s age on human sperm protein expression and phosphorylation to identify molecular alterations possibly responsible for the age-associated decline in male fertility. Semen samples from volunteers attending fertility consultations at the Hospital of Aveiro were collected, analyzed according to WHO’s guidelines, and processed by the density gradient technique. The proteome and phosphoproteome of 19 normozoospermic human sperm samples divided into four age groups were evaluated by mass spectrometry: ≤30 years old; 31–35 years old; 36–40 years old; and >40 years old. Proteomic analysis revealed 46 differentially expressed proteins (DEPs) between groups, some of them associated with infertility-related phenotypes. Gene ontology (GO) analysis, performed using the DAVID database, revealed that DEPs in older men were enriched in pathways related to stress response, metabolism, and embryo implantation. Additionally, 94 differentially phosphorylated sites corresponding to 76 differentially expressed phosphorylated proteins between the groups were identified, related to key reproductive processes such as sperm motility, spermatogenesis, and sperm binding to zona pellucida, and involved in metabolic and stress response pathways, like HSF1 activation. The set of proteins and phosphorylated residues altered in the sperm fraction usually used in assisted reproductive technology (ART) highlights the need to consider the age of the male partner during fertility assessment and treatment planning. These markers can also be used to explain cases of idiopathic infertility, failure in ART, or repeated abortion associated with APA, overcoming the subjectivity of the conventional semen analysis. Full article

Previous studies have shown mouse antigenotoxic and chemopreventive potential with the administration of Citrus paradisi juice (GJ). To evaluate another activity, the aim of the present report was to determine the beneficial effect of GJ on male mouse reproductive damage induced by cadmium chloride (CC). Seven groups of mice were intragastrically (IG) administered for 11 days. A control group was administered purified water daily, three groups were administered GJ daily (4.1, 16.6, and 33.2 µL/g), plus a single administration of CC (3 mg/kg) on the fifth day of the assay, another group was treated daily with 33.2 µL/g GJ, and a positive control group was treated with 3 mg/kg of CC on day 5 of the experiment. The results with the high GJ dose on the CC-treated mice showed a mean reduction of 88% in sperm quality endpoints (viability, motility, malformations) and a 94% sperm concentration increase. With the same dose, we also determined an 81% reduction in the DNA breaking potential and in the number of micronuclei in the spermatids. We also found an 87% decrease in lipoperoxidation and a 68% decrease in protein oxidation with respect to the CC damage, and a strong DPPH scavenging ability. Our results suggest the potential involvement of the GJ antioxidant in the observed effect. Full article

Background: Sperm morphology is a key factor influencing fertilization and embryo development in assisted reproductive technology (ART). However, the predictive value of sperm deformity indices and selection techniques remains debated. This study evaluated the impact of teratozoospermia on fertilization, blastocyst formation, and embryo quality, comparing conventional and microfluidic sperm selection methods. Methods: A retrospective analysis was conducted on ART cycles involving patients with teratozoospermia. Sperm selection was performed using density gradient centrifugation (DGC) or microfluidic sperm sorting (MFSS). The correlations between the Sperm Deformity Index (SDI), Multiple Anomalies Index (MAI), and Teratozoopermia Index (TZI) with fertilization rates, blastocyst formation, and embryo quality were assessed. Statistical analysis included correlation tests, receiver operating characteristic (ROC) curves, and independent samples t-tests. Results: Patients with severe teratozoospermia exhibited lower fertilization rates (p < 0.01) and reduced blastocyst formation (p = 0.02). The SDI and MAI showed moderate negative correlations with fertilization (r = −0.15 and r = −0.25, respectively) and blastocyst development (r = −0.20 and r = −0.30, respectively), while the TZI had only weak associations (r = −0.10 and r = −0.15, respectively). ROC analysis demonstrated that the SDI and MAI were moderate predictors of embryo viability (AUC = 0.70 and 0.75, respectively). Patients who underwent microfluidic sperm selection had higher fertilization rates (p = 0.03) and improved blastocyst quality (p = 0.04) than those processed with DGC. Conclusions: Severe teratozoospermia negatively affects fertilization and blastocyst formation, with the SDI and MAI showing moderate predictive value for embryo development. The use of microfluidic sperm selection significantly improved embryo quality, supporting its clinical relevance in ART. Full article

Obesity is a major contributor to male infertility, not only exacerbating infertility but also impairing the effectiveness of both surgical interventions and medical treatments. This review examines the complex relationship between obesity, the immune microenvironment, and male infertility, highlighting how obesity-induced changes in immune function lead to testicular dysfunction and impaired spermatogenesis. Key mechanisms include chronic low-grade inflammation, immune cell infiltration, and dysregulated adipokines such as leptin and adiponectin. We also explore current therapeutic strategies aimed at alleviating these effects, including lifestyle interventions, anti-inflammatory treatments, metabolic therapies, and regenerative medicine approaches, such as exosome-based therapies. Despite promising results, substantial research gaps remain, particularly in understanding the molecular mechanisms and identifying novel biomarkers for early diagnosis. Future studies should focus on multi-omics approaches, large-scale cohort studies, the gut–testis axis, and the psychological and social factors influencing male infertility. A deeper understanding of these processes is crucial for developing more effective, targeted therapies for obesity-related male infertility. Full article

Background: The testis, a critical reproductive organ in male animals, is responsible for sperm production and androgen secretion. Testis weight often correlates with reproductive performance, yet the genetic factors influencing testicular traits in chickens remain unclear. Methods: Previous genome-wide association studies (GWAS) have identified key genes affecting testicular traits in Kangle Yellow chickens, along with the associated regulatory pathways and Gene Ontology (GO) terms, through bioinformatic analyses. In this study, we utilized the existing literature, full-length transcriptome data, and proteome analyses to select key candidate genes. Results: We identified 13 associated markers for chicken testicular traits with 262 candidate genes. Nine candidate genes were found to regulate chicken testicular traits referred to integrated analysis, including CDH3, ZFPM1, CFAP52, ST6GAL1, IGF2BP2, SPG7, CDT1, NFAT5, and OPRK1. Physical interactions among these genes were also observed, implicating mechanisms such as cell adhesion molecules and neuroactive ligand–receptor interaction. Conclusions: These findings provide a genetic basis for improving testicular traits in Chinese native chicken breeds. Full article

Mouse sperm-associated antigen 6-like (SPAG6L) evolved from SPAG6, the mammalian ortholog of Chlamydomonas PF16, which is localized in the central apparatus of the motile cilia and is essential for ciliary motility. Even though the amino acid sequences of the two SPAG6 proteins are highly similar, the two proteins have different biological expression patterns in vivo. No major phenotypes were discovered in the global Spag6 knockout mice. However, the global Spag6l knockout mice demonstrated multiple phenotypes in tissues with and without cilia. Since SPAG6L decorates microtubules and modulates cytoskeleton function, and Sertoli cells have a well-developed microtubule transport network, the potential function of SPAG6L in Sertoli cells was evaluated. The floxed Spag6l mice were crossed with Amh-Cre transgenic mice to inactivate the Spag6l gene specifically in Sertoli cells. Surprisingly, the fertility of the homozygous mutant males was not reduced. The testis size and sperm number and motility showed no significant difference to those of the control mice. Testicular histology also showed normal spermatogenesis. No significant changes were observed in the number of Sertoli cells and blood–testis barrier function. Our study showed that the inactivation of only Spag6l does not affect Sertoli cell function during the first 6 months of life. Full article

Heat stress impairs spermatogenesis primarily through increased testicular oxidative stress. Astaxanthin, a potent antioxidant, has shown beneficial effects in sperm cryopreservation. However, its potential to mitigate testicular damage induced by elevated temperatures remains uninvestigated. In this study, male mice were administered astaxanthin (10 mg/kg/d, 50 mg/kg/d, and 100 mg/kg/d) via gavage for 21 days, with heat exposure occurring during the final 14 days. Samples were collected after the last treatment or following a recovery period. Spermatozoa in the cauda epididymis were assessed using computer-aided sperm analysis (CASA) or Diff-Quik staining, and serum testosterone levels and oxidative stress markers in both serum and testis were quantified via enzyme-linked immunosorbent assay (ELISA). Heat treatment resulted in significant reductions in sperm motility, viability, and morphological integrity. However, daily supplementation of astaxanthin at 50 mg/kg and 100 mg/kg effectively alleviated these heat-induced impairments. Furthermore, astaxanthin at 50 mg/kg/d notably improved testis weight, testis index, and serum testosterone levels under heat stress. Its antioxidant capacity was validated by significant restoration of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and reduction in malondialdehyde (MDA) levels in both testis and serum. In conclusion, this study highlights the protective effects of astaxanthin against heat-induced testicular and sperm damage by reducing oxidative stress, supporting its potential use as a nutritional or nutraceutical supplement to promote male reproductive health, particularly in the context of summer subfertility in farm animals. Full article

As a surface-located molecule in biological membranes, cholesterol sulphate (CholS) plays a major role in membrane-driven cell–cell processes and events including platelet-cell adhesion, T-cell receptor signalling, sperm–egg interaction, membrane fusion, and skin differentiation. Despite this, little is known about the biophysical implications of CholS at the membrane in cells and organelles. In this study, we investigate the effect of increasing the content of CholS on the biophysical properties in cholesterol-poor and cholesterol-rich biomimetic models. Data obtained show that increasing amounts of CholS result in a slight increase in anisotropy, evidence for decreased membrane fluidity at higher CholS content (10 mol%) in cholesterol-poor systems but only negligible in rigidified epithelial-like cholesterol-rich systems. On the other hand, incorporation of CholS has an overall increasing ordering effect on membrane organisation and on-surface potential that is influenced by the lipid composition and cholesterol content. Though further research is needed to gain better insights on the (patho)physiological levels of CholS in cells and organelles, our findings are discussed in the context of diet–microbiota–host interactions in membrane-driven events in inflammatory-related disorders. Full article

The concurrent occurrence of summer heat stress and the non-breeding season has significantly impaired the semen quality of rams. Currently, there exists no straightforward and efficient method to address this issue. In this study, we demonstrate that two consecutive administrations of melatonin implants significantly mitigate the adverse effects of summer heat stress and the non-reproductive season on rams. Our findings indicate that implantation of exogenous melatonin enhances semen quality by improving sperm DNA integrity, mitochondrial integrity, and decreasing the proportion of abnormal sperm, as compared to control rams. This improvement is ascribed to the alleviation of oxidative stress and the optimized regulation of endocrine hormone levels in both serum and seminal plasma. Further exploration of the regulatory mechanism reveals that melatonin can also influence the tryptophan metabolism pathway. Additionally, our study revealed that certain indices and metabolites are strongly correlated with semen quality and can potentially serve as indicators for research aimed at improving semen quality. Notably, this is the first time that differences in tryptophan metabolites between serum and seminal plasma have been elucidated. All the above information suggests that melatonin implantation can protect sperm from heat stress by optimizing the blood and semen microenvironment. Full article

Several viruses have demonstrated the potential for infecting the human male genital tract, leading to potential host pathologic consequences and sexual transmission. Despite the testes being an immune-privileged niche of the body, viruses like Zika, mumps, Ebola, Marburg, and human immunodeficiency virus infect the lumen of testes. The human blood–testis barrier (BTB) is a specialized epithelial barrier responsible for protecting the developing sperm in the lumen of the seminiferous tubules from foreign antigen; however, testicular-tropic viruses possess the unique ability to modulate this barrier prior to entry into the lumen. Previous scientific reports identified immunomodulatory and viral-induced changes to BTB physiology during infection—a necessary step prior to viral entry into the testicular lumen. This review aims to explore the specific mechanisms employed by viruses to disrupt the human BTB and establish testicular infection. Full article

Horses and donkeys, as integral members of the equine family, exhibit distinct reproductive capabilities and characteristics. Seminal plasma, the fluid component of semen, contains a variety of proteins that play critical roles in sperm function and fertility. This study aimed to systematically compare the protein profiles in the seminal plasma of horses and donkeys, thereby elucidating the molecular differences between these two species. The study utilized 4D-DIA proteomics technology to analyze seminal plasma from horses and donkeys and further validated key proteins through Western blot. Our findings revealed significant variations in seminal plasma protein composition between horses and donkeys. We identified 2380 and 2385 proteins in the seminal plasma of horses and donkeys. Among these proteins, 59 are solely present in the seminal plasma of horses, and 64 uniquely exsit in that of donkeys, respectively. These insights enhance our understanding of the biological mechanisms underlying the reproductive distinctions between these equine species. Moreover, the identified species specific proteins may be essential for thier sperm quality and function, which holds practical value for breeding programs and investigations. Full article