Search Results (155)

Sperm morphology is one of the most critical indicators of male fertility. This paper presents a deep learning-based approach to classify sperm cells into 18 morphological classes, including one normal and 17 abnormal types. Two state-of-the-art convolutional neural networks, EfficientNetV2-S and ResNet50V2, are employed and fine-tuned using a class-weighted loss function together with extensive data augmentation to improve generalization under class imbalance. Automatic mixed precision training is adopted to reduce memory consumption and accelerate the training process. An ensemble strategy is subsequently constructed by linearly fusing the logits of both architectures, where the fusion weight is optimized to maximize recall, precision, and overall F1-score. Experimental results show that the proposed ensemble achieves an overall accuracy of 70.94%, consistently outperforming the individual models. Sperm cells with pronounced structural abnormalities, such as PinHead and DoubleTail, are classified with high accuracy, whereas less visually distinctive defects result in comparatively lower performance. These findings demonstrate the potential of CNN-based ensemble models to provide consistent and reliable automated sperm morphology classification. Full article

Studies of adult depressed patients report that selective serotonin (5-HT) reuptake inhibitors (SSRIs) like clomipramine (CMI) have secondary effects on sperm quality. The epididymis possesses an autonomous serotonergic system critical for sperm maturation, whose establishment during neonatal development remains unexplored as a target for SSRI programming. We hypothesized that neonatal CMI exposure would disrupt the developing epididymal 5-HT system, leading to permanent sperm dysfunction. CMI (30 mg/kg s.c.) was administered to male rats between postnatal days 8–21. At 3 months, sperm from the epididymal cauda was evaluated, and 5-HT levels were measured in the testis, caput, and cauda epididymis. Our novel findings demonstrate that neonatal CMI exposure induces region-specific, long-term alterations in epididymal 5-HT levels (decreased in caput, increased in cauda) without affecting testicular 5-HT. This reprogramming of the local serotonergic milieu was associated with reduced sperm concentration, viability, normal morphology, and motility, alongside increased mitochondrial activity and reactive oxygen species. This study reveals, for the first time, that the epididymal serotonergic system is a key target for neonatal SSRI programming, providing a mechanistic link (altered 5-HT homeostasis) between early-life exposure and persistent sperm defects in adulthood. Full article

Oxidative stress (OS) is a major cause of defective sperm function. During laboratory handling, gametes are exposed to OS, potentially mitigated by in vitro antioxidant supplementation. This study evaluates the protective role of caffeic acid (CAF) on basal human semen and under induced OS. First, six semen samples from normozoospermic donors were incubated with CAF concentrations ranging from 50 to 500 µM at 37 °C for 2 h. Sperm motility and DNA integrity (acridine orange) were evaluated. Then, ten semen samples were divided into four aliquots and incubated, respectively, with CAF at 100 µM, H₂O₂ at 2 mM, or H₂O₂ at 2 mM + CAF at 100 µM, or untreated. Motility, DNA integrity, acrosome status (Pisum sativum agglutinin), OS quantified by F₂-isoprostanes (ELISA), and expression of Nrf2, Keap1, and HO-1 (qRT-PCR) were assessed. CAF at 100 µM improved progressive motility without damaging DNA and was selected for subsequent experiments. CAF showed protective effects on sperm damage induced by H₂O₂ treatment, restoring motility, DNA integrity, and acrosome status and reducing F₂-isoprostane levels. Nrf2 and HO-1 expression were upregulated by CAF, downregulated by H₂O₂, and restored by the co-treatment. CAF supplementation may protect human spermatozoa during in vitro handling by reducing OS, improving several sperm parameters, with a possible mechanism of action involving the Nrf2 pathway. Full article

Spermiogenesis requires extensive molecular and structural remodeling to produce motile sperm. Mutations in the testis-specific RNA methyltransferase NSUN7 are associated with defective fibrous sheath, impaired sperm motility, and male infertility. However, the underlying molecular mechanisms remain poorly understood. Here, we performed proteomic profiling of sorted, elongated, and round spermatids, as well as mature spermatozoa from Nsun7 knockout mice. We showed that NSUN7 is present at all stages of spermiogenesis and is most abundant in round spermatids, which corresponds to the formation of the flagellum and fibrous sheath assembly. Loss of NSUN7 altered the abundance of proteins essential for dynein arm assembly (PIH1D3, CCDC103, CCDC40), intraflagellar transport (IFT122), and fibrous sheath organization (AKAP3, AKAP4, ROPN1L). We also showed that the previously detected impaired retention of cytoplasm in elongated spermatids may be caused by plectin accumulation. Interestingly, no statistically significant changes were found in mature sperm proteomes upon Nsun7 inactivation. Our findings support a model in which NSUN7 primarily stabilizes protein complexes and coordinates flagellar assembly. This indicates that NSUN7 is a critical regulator of spermiogenesis, and its malfunction is a contributing factor to male infertility. Full article

Male reproductive disorders and declining fertility rates play an important role in birth rates, and their impact on future populations makes them one of the most serious public health issues of this century. Defects in spermatogenesis are the most common manifestation of male infertility, and exposure to environmental pollutants has been suggested as a potential cause. Nanomaterials, due to their unique physicochemical properties and widespread application, have raised growing concerns about their potential reproductive toxicity. Studies have shown that nickel nanoparticles (Ni NPs) have reproductive toxicity in male rats and mice, especially sperm damage. This study aimed to explore the male reproductive toxicity of Ni NPs and the role of mitochondrial fission in mouse spermatocytes (GC-2). Our results showed that Ni NPs induced the damage of mitochondrial structure and function in GC-2 cells and disrupted intramitochondrial homeostasis, thereby resulting in enhanced Dynamin-related protein 1(Drp1)-mediated mitochondrial fission and cell apoptosis, along with aggravated cytotoxicity and obvious reproductive toxicity. The mitochondrial division inhibitor 1(Mdivi-1) and lentiviral-transfected low expression of Dnm1l can significantly alleviate the germ cell toxicity caused by Ni NPs, suggesting a certain therapeutic effect. The novelty of this study lies in its systematic demonstration that Drp1-mediated mitochondrial division is a core pathogenic mechanism of Ni NP-induced male reproductive toxicity, and the validation of both pharmacological inhibition and genetic silencing as effective intervention strategies. Therefore, this study offers a reference for expanding the reproductive toxicity effect of Ni NPs and potential molecular mechanisms and provides an important basis for finding potential targets and treatment of Ni NPs. Full article

Assisted reproductive technologies (ART) and, in particular, intracytoplasmic sperm injection (ICSI) transformed the management of male infertility by making fertility possible in previously untreatable cases. However, the bypassing of natural selection mechanisms at fertilization is fraught with the danger of transmission of genetic and epigenetic abnormalities. Male infertility is now a multifactorial disorder with notable contributions from single-gene defects, chromosomal abnormalities, and Y-chromosome microdeletions. The recent advances in next-generation sequencing and sperm omics have identified mutations and copy-number variations in genes critical for spermatogenesis, flagellar structure, and endocrine regulation. Along with these findings, an increasing body of evidence suggests that ART procedures can lead to a disruption of epigenetic reprogramming during gametogenesis and early embryogenesis, resulting in imprinting disorders and altered patterns of gene expression in the offspring. This review synthesizes recent progress in the molecular underpinnings of genetic and epigenetic hazards of ART, with an emphasis on clinical significance for reproductive counselling and ethical considerations for future generations. Full article

Observations of the processes of oogenesis, fertilization, and the earliest embryonic development have given us the opportunity to estimate the importance of chromosomal distribution errors for the success of mammalian reproduction. It is now known that in the large volume of oocytes, zygotes and the first embryonic cells, the rearrangement of chromatin is associated with a complex rearrangement of cytoskeletal structures, which creates specific problems. This review discusses two main issues critical to the success of early embryos: Why oocyte meiosis is too frequently wrong in chromosomal segregation? Why the first zygotic mitoses are too frequently wrong in chromosomal segregation? We concluded the following: (1) The main cytoskeletal defects that disturb oocyte meiosis are a problematic connection between cytoskeleton and nucleoskeleton, unsuccessful movement of the spindle to the oocyte periphery, unstable anchoring of the spindle to oolemma, and deviations in meiotic spindle morphology; (2) The main cytoskeletal defects that disturb pronuclear unification are nonfunctional male centriole, unsuccessful forming of microtubule aster around the sperm centrosome, problematic movement of the two pronuclei towards each other and inappropriate contacts between centrosomes, microtubules and nuclear pore complexes; (3) Cytoskeletal defects that disturb zygote mitosis are unsuccessful forming of bipolar mitotic spindle, non-synchronized congression of maternal and paternal chromosomes, and unsuccessful attachment of kinetochores to microtubules. Full article

Alpha-lipoic acid (ALA) is well-known for its antioxidant and anti-inflammatory functions in various disease models. Here, we tested whether pre-exposure to ALA can protect the testes from cellular damage caused by scrotal heat shock (HS) in mice. Methods: Thirty-six Swiss albino mice were divided into control (CTRL, n = 6), HS (n = 10), and two ALA dose (HS + ALA 200 mg/kg, n = 10; and HS + ALA 400 mg/kg, n = 10) groups. ALA supplementation was administered orally for 30 days. Subsequently, the animals, except the controls, were subjected to an HS water bath at 43 °C for 20 min. Two days later, they were euthanized, and biometric data from gonads and accessory sexual glands, testicular samples for histomorphometric and immunohistochemical analyses, and sperm from the epididymis cauda were obtained for evaluation. Results: Animals submitted to HS had a lower body weight, decreased relative mass of testes and prostate, reduced seminiferous epithelium height and tubular diameter, and increased degeneration in seminiferous tubules. Additionally, sperm analysis showed a reduced linear progressive velocity (VSL) and straightness (STR), increased midpiece defects, and fewer sperm with functional membranes. Immunohistochemical evaluation revealed a reduced superoxide dismutase (SOD1) staining intensity in the testes. Preventive exposure to ALA at 200 mg/kg did not normalize the relative testicular mass, but it reduced the number of giant cells, decreased midpiece defects, normalized the number of sperm with functional membranes, and partially preserved SOD1 expression. Although animals treated with ALA 400 mg/kg showed an improvement in relative testicular mass, this dose was less efficient in other parameters. Conclusions: This study showed that while 30 days of oral ingestion of ALA before the induction of acute degenerative injury did not fully protect male mouse gonads at the tissue level, some parameters related to testicular function and sperm quality showed a partial improvement. Full article

Idiopathic male infertility (IMI), which accounts for nearly 50% of male infertility cases, remains a major clinical challenge due to the inability of standard semen analysis to reveal underlying molecular defects. Post-translational modifications such as lysine acetylation are increasingly recognized as key regulators of sperm function, affecting antioxidant defense, energy metabolism, and spermatogenesis. In this study, global acetyl-proteomic profiling of spermatozoa from idiopathic infertile patients (IIP) and fertile donors (FD) was performed using immunoprecipitation-based enrichment followed by high-resolution LC–MS/MS. Bioinformatics analyses, including STRING, Cytoscape, and Ingenuity Pathway Analysis (IPA), identified 718 differentially acetylated proteins (DAPs), with significant enrichment in pathways related to redox homeostasis, molecular transport, glycolysis, and mitochondrial metabolism. Hub proteins such as SOD1, PARK7, and PRKACA emerged as key regulators linking oxidative stress with defective motility and impaired sperm physiology. Western blot validation confirmed the downregulation of these hub proteins in IIP, supporting their role in redox imbalance and mitochondrial dysfunction. Our findings highlight dysregulated lysine acetylation as a defining molecular feature of IMI and suggest that targeting acetylation-associated pathways may provide novel diagnostic biomarkers and therapeutic strategies to improve sperm function and male reproductive outcomes. Full article

Background/Objectives: Acephalic spermatozoa syndrome (ASS) is a rare subtype of male infertility characterized by headless sperm due to defective head–tail coupling. Genetic factors are recognized as the primary etiology of ASS; however, known pathogenic mutations only explain a subset of ASS cases. Further investigations are required to elucidate the underlying genetic pathogenesis of ASS and the implications of such genetic defects for assisted reproductive technology (ART) outcomes. This study aimed to identify a novel PMFBP1 mutation in an ASS patient; investigate the effects of the identified mutation on sperm ultrastructure and PMFBP1 protein expression/stability, and assess ART outcomes using the patient’s sperm. Methods: One 34-year-old infertile male with ASS was enrolled. Genetic screening was performed via whole-exome sequencing (WES), followed by Sanger sequencing for mutation validation. Sperm morphological characteristics were evaluated using Diff-Quik staining (for general morphology), transmission electron microscopy (TEM, for ultrastructural analysis), and peanut agglutinin (PNA) staining. Protein expression and stability were analyzed by Western blot and cycloheximide (CHX)/MG132 assays. ART outcomes were compared between the in vitro fertilization (IVF) cycles using the patient’s sperm and those using donor sperm. Results: In IVF cycles, donor sperm achieved normal fertilization (characterized by two pronuclei [2PN] formation), whereas the patient’s sperm failed to form 2PN and leading to embryo fragmentation. Genetic sequencing identified a novel nonsense mutation in PMFBP1 (c.2641C>T), which introduced a premature stop codon and resulted in a premature protein product (p.Arg881Ter). Morphologically, this mutation led to complete sperm head–tail detachment, and abnormalities in acrosome structure and sperm head–neck junction. The absence of PMFBP1 protein in the patient’s spermatozoa was observed. The in vitro assays showed the c.2641C>T mutation induced expression of the truncated PMFBP1 protein and significantly altered PMFBP1 protein stability. Conclusions: The PMFBP1 c.2641C>T mutation impairs sperm head–tail adhesion, thereby contributing to the pathogenesis of ASS. This study expands the clinical mutational spectrum of PMFBP1-associated male infertility and provides valuable insights for the genetic diagnosis of ASS patients. Additionally, these findings may lay a foundation for the choice of therapeutic strategies targeting PMFBP1-related ASS. Full article

Background: Male infertility is evaluated using standard semen parameters. However, these criteria offer limited insight into sperm functionality and poorly predict natural fertility or assisted reproductive technology (ART) outcomes. Methods: In this study, the expression levels of three genes (AURKA, HDAC4, and CARHSP1) involved in mitosis regulation, epigenetic modulation and early embryonic development, were measured by RT-qPCR in sperm samples (training dataset). For each gene, thresholds of normal and reduced expression were established by biostatistical modeling and combined with the number of motile spermatozoa to develop the Spermatozoa Function Index (SFI). Results: The ROC analysis was used to interpret the SFI values: SFI > 320 (normal), 290–320 (intermediate), and <290 (low). Then, this index was validated using 627 fresh semen samples from 25- to 60-year-old men at our ART center. Based on the World Health Organization criteria, 54.5% of the 627 sperm samples were normospermic, 8.8% showed oligo-astheno-teratospermia, and 36.6% had one or two abnormal parameters. According to the SFI values, 41% of sperm samples displayed normal expression, 55.9% low expression, and 4.1% intermediate expression. Only 57% of the 342 normospermic samples had normal SFI values and 37% had low SFI values. Among the 81 samples with stringent normal criteria (≥50 million/mL, ≥50% total motility, ≥14% normal morphology), 67.9% displayed normal SFI and 22.2% low SFI values. These findings suggest that even sperm with normal parameters may harbor dysfunctions. Conclusions: Our data highlight a gene signature with strong discriminatory power and promising diagnostic value for detecting subclinical sperm defects and improving male infertility assessment. Full article

Sperm morphology analysis is critical for assessing bovine fertility, since it provides insight into bull reproductive potential as well as subfertility and infertility. Traditional sperm morphology analysis is time-consuming, subjective, and prone to human error, all of which highlight the need for automated, objective solutions. This study presents the design and implementation of a computer-aided system for bovine sperm morphology analysis, leveraging deep learning models to detect and classify sperm cells based on their morphological characteristics. Using micrographs of bull sperm, we present a sequential deep learning framework that automatically detects morphological sperm aberrations. The model segments and analyzes each cell, identifying defects in the head, neck/midpiece, tail, and residual cytoplasm. Specifically, the system employs the YOLOv7 object detection framework, trained on a dataset of 277 annotated images comprising six morphological categories, to automatically identify and classify sperm abnormalities. The experimental results demonstrate a global mAP@50 of 0.73, precision of 0.75, and recall of 0.71, indicating a balanced tradeoff between accuracy and efficiency. By reducing reliance on manual analysis, this work enhances efficiency and accuracy in animal reproduction laboratories, contributing to veterinary reproduction through a cost-effective and scalable solution for sperm quality assessment. Full article

Dietary fiber plays an important role in animal nutrition by influencing gut health, feed intake, and metabolism. In swine production, studies suggest that fibers may also affect reproductive traits, but findings remain inconsistent, especially in adult boars. This study evaluated the effects of partially fermentable insoluble fiber (PFIF) on semen quality, behavior, and general health of adult boars. Thirty animals were assigned to a completely randomized design with two treatments: (1) CON: no fiber supplementation, and (2) PFIF: fiber supplementation (35 g/animal/day). Fiber was provided once daily for 120 consecutive days. During the period, semen was collected weekly and analyzed macroscopically and microscopically using the Computer-Assisted Sperm Analysis (CASA) system. Behavior was recorded weekly, one and three hours after feeding, based on a pre-established ethogram. Feed intake, perineal, and fecal scores were also evaluated. Fiber supplementation did not affect total motility, progressive motility, sperm concentration, fecal or perineal scores, or behavior. However, improvements were observed in sperm kinematics, with higher straight-line distance (DSL), linearity (LIN), and straightness (STR), as well as a tendency for increased straight-line velocity (VSL) and wobble (WOB). Conversely, a higher incidence of proximal cytoplasmic droplets was recorded in the fiber group, indicating more sperm maturation defects. Supplemented animals also showed reduced feed intake compared with controls, suggesting a satiety effect of the fiber. In conclusion, PFIF supplementation (35 g/animal/day offered once daily) in adult boars produced mixed outcomes, with improved sperm kinematics but increased maturation defects and only minor changes in feeding behavior, indicating a limited and inconsistent physiological response. Full article

Bulls can develop various conditions affecting the penis, testicles, and associated structures that reduce fertility, spread disease, and increase costs for farmers. This review synthesizes data from farm fertility examinations and slaughterhouse findings to illustrate the prevalence of these conditions, their causes (including inherited defects, infections, and injuries), their impacts on breeding, and potential interventions. Conditions discussed include orchitis, testicular hypoplasia, testicular degeneration, testicular hydrocele, malignant tumors, spermatocele, penile papillomatosis, and penile hematoma. Lameness and systemic illnesses can also impair a bull’s breeding ability. Regular fertility examinations assessing overall health, testicle size, semen motility, and sperm morphology, coupled with timely medical or surgical treatment, can improve reproductive outcomes. Maintaining national records of birth defects and health histories could aid in preventing the transmission of deleterious traits. Reducing these disorders enhances animal welfare, protects herd fertility and the food supply, and supports the economic viability of cattle producers. Full article

Cannabis is one of the most studied psychoactive substances due to its increasing prevalence and evolving legal status. Of particular concern is the rising consumption among young individuals, where excessive use may disrupt reproductive processes and pose long-term health risks to offspring. This narrative review examines the effects of cannabis use on male and female reproductive health, including its impact on male fertility, the female reproductive system, placental function, and prenatal and postnatal outcomes, as well as fetal development. A nonsystematic review was conducted using PubMed, Scopus, Web of Science, and Google Scholar databases in November 2024. After screening titles and abstracts and the full-text analysis, 64 studies were included in this narrative review. In men, cannabinoids can interfere with spermatogenesis, reduce sperm motility and quality, and lower testosterone levels, as demonstrated in clinical and experimental studies. In women, cannabinoid-induced disorders include negative effects on ovarian follicle maturation, ovulation, placental function, and prenatal development. Prenatal exposure to cannabis is associated with the risk of reduced birth weight, birth defects, sudden infant death syndrome (SIDS) or lactation problems due to the penetration of cannabis metabolites into breast milk. The findings highlight the potential negative effects of cannabis on reproductive health and fetal development. Given these risks, individuals attempting to conceive, and pregnant women should be advised against cannabis use. Greater awareness is needed among healthcare professionals and the public regarding the reproductive risks associated with cannabis consumption. While the evidence on teratogenic effects is not always conclusive, caution should be exercised, and further research is essential to deepen the understanding of these effects. Full article