Search Results (109)

Heat stress (HS) severely impairs boar reproductive function by inducing oxidative stress and inflammatory responses, while lycopene (LYC), as a potent antioxidant, exerts a potential protective effect on the male reproductive system. This study aimed to clarify the mechanism underlying LYC-mediated alleviation of HS-induced decline in semen quality in Rongchang boars, identify the most affected tissues, and explore its regulatory role in the Nrf2 (Nuclear factor E2-related factor 2) pathway. A total of 18 Rongchang boars with an initial body weight of 15.81 ± 1.07 kg were randomly assigned to three groups (6 boars per group): the control group (CON, 26 ± 1 °C), the heat stress group (HS, exposed to 35 ± 1 °C for 8 h daily), and the heat stress + 100 mg/kg lycopene group (HS + LYC). After 28 days of adaptive feeding and 14 days of HS treatment, samples were collected for semen quality analysis, testicular histological analysis, antioxidant index detection, transcriptome analysis, Nrf2 pathway detection, and inflammatory index detection. The results showed that HS significantly increased the sperm abnormality rate (p < 0.05), damaged the testicular structure, and induced oxidative stress in serum, lung, liver, left ventricle, testis, and epididymis (caput epididymis, corpus epididymis, cauda epididymis), with varying degrees of oxidative stress observed in these samples. Among these tissues, the testis and cauda epididymis exhibited the most significant responses to HS and LYC, with the comprehensive impact magnitudes of 317% and 514%, respectively. Enrichment analysis of differentially expressed genes (DEGs) in these two tissues revealed that the pathways mediating oxidative stress response displayed distinct tissue specificity, and all of them were closely associated with the Nrf2 antioxidant signaling pathway. HS significantly downregulated the mRNA expressions of Nrf2, Quinone Oxidoreductase (NQO1), Heme Oxygenase 1 (HMOX1) and Glutamate-Cysteine Ligase Catalytic Subunit (GCLC) genes as well as the protein level of Nrf2 in the testis and cauda epididymis, increased the protein level of Keap1, and significantly elevated the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in these two tissues (p < 0.05). Compared with the HS group, dietary supplementation of LYC significantly improved sperm motility and the proportion of rapidly progressive sperm, reduced the proportion of immotile sperm and sperm abnormality rate (p < 0.05), alleviated testicular damage and oxidative stress in various tissues, upregulated the mRNA expressions of Nrf2 and HMOX1 genes in the testis as well as the mRNA expressions of Nrf2, NQO1, HMOX1 and GCLC genes in cauda epididymis (p < 0.05), significantly increased the Nrf2 protein level and decreased the Keap1 protein level in these two tissues, and simultaneously decreased the levels of the aforementioned inflammatory factors (p < 0.05). In conclusion, dietary supplementation with 100 mg/kg LYC can alleviate HS-induced decline in semen quality and testicular damage by regulating the oxidative status and inflammatory level of relevant tissues (e.g., testis and cauda epididymis) in boars, and this protective effect may be associated with the regulation of the Nrf2 signaling pathway. Full article

This study aimed to determine the sexual maturation pattern of Shenxian pigs by combining observation, teaser boar testing, and back-pressure methods, and to apply this pattern for early breeding to shorten the generation interval and increase production efficiency. Subsequently, high-throughput transcriptome technology was used to compare gene expression levels in testicular tissues of Shenxian pigs before and after sexual maturity, as well as between sexually mature Shenxian pigs and Shenxian × Large White crossbred pigs. Functional analysis of differentially expressed genes (DEGs) was conducted to screen candidate genes related to sexual maturation and precocity in Shenxian pigs. The results showed that boars reached sexual maturity at an average age of 116 days in winter and 129 days in summer. For sows, the first estrus occurred at 114 days, the second at 134 days, and the third at 154 days in winter; corresponding ages in summer were 125, 144, and 164 days, respectively. The duration of estrus was around 3 days, and the estrus interval was approximately 20 days for both seasons. Comparative trials revealed no significant change in production performance when selection and first mating were conducted at 5 months of age compared to previous practices. Transcriptome sequencing of testicular tissues before and after sexual maturity in Shenxian pigs identified 6016 upregulated genes, primarily associated with reproduction and sperm function, influencing sexual maturation. The comparison between sexually mature Shenxian pigs and crossbred pigs identified 582 upregulated genes, mainly involved in hormone synthesis, affecting the onset of puberty in Shenxian pigs. After intersecting and functionally analyzing the upregulated genes from both sets, SRD5A1 and CYP11B2 were selected as the most likely candidate genes to affect precocious puberty in Shenxian pigs. Full article

Spermatogenesis is a sophisticated process coordinated by germ cells and the somatic microenvironment. Circular RNAs (circRNAs), key components of competitive endogenous RNA (ceRNA) networks, form intricate post-transcriptional regulatory systems by sequestering microRNAs (miRNAs). However, the specific functions of these networks in spermatogenesis, particularly regarding the cell-intrinsic regulatory programs of germ cells, remain poorly understood. To address this, we utilized a unique foxl3 mutant model in medaka (Oryzias latipes), in which XX female germ cells spontaneously transdifferentiate into functional sperm within the ovarian somatic environment. This model enables the functional enrichment of core spermatogenic programs largely independent of male-specific somatic cues. Through whole-transcriptome sequencing and bioinformatic analysis, we identified 58 key circRNAs, 27 core miRNAs, and 2965 mRNAs, and constructed a candidate ceRNA regulatory network mediated by six circRNAs. Under genetically consistent conditions, this study elucidated a putative ceRNA network directly involved in the germ cell-dominant initiation of spermatogenesis, suggesting an essential role of these networks in germ cell fate determination. These findings provide new insights into the regulatory mechanisms of teleost spermatogenesis and offer valuable molecular targets for advancing reproductive medicine and improving breeding efficiency in aquaculture. Full article

Conventional semen analysis fails to capture the molecular determinants underlying impaired reproductive function. Emerging evidence positions seminal plasma (SP) and extracellular vesicles (EVs) as dynamic regulators of sperm physiology, rather than passive transport components. SP, enriched with proteins, metabolites, hormones, and antioxidants, modulates sperm motility, capacitation, acrosome reaction, and immune tolerance. Complementarily, EVs, including prostasomes, epididymosomes, and testicular vesicles, deliver proteins, lipids, and small RNAs that remodel sperm membranes, protect against oxidative insults, and influence fertilization success. A critical dimension of the SP-EV axis is its role in balancing oxidative stress (OS) and endocrine signaling. Hormones and metabolic regulators within SP, together with EV-mediated transfer of receptors and regulatory RNAs, further integrate systemic metabolic health with local reproductive outcomes. Dysregulation of these networks, particularly in conditions such as varicocele, obesity, diabetes, and idiopathic infertility, compromises sperm function and reduces assisted reproductive technology (ART) success. This evidence-based review synthesizes current evidence on SP and EVs as ‘molecular gatekeepers’ in male infertility, emphasizing OS regulation, endocrine crosstalk, and their potential as biomarker reservoirs. By integrating proteomic, metabolomic, and transcriptomic insights, the translational opportunities for biomarker-informed diagnostics, prognostication, and therapeutic interventions are highlighted. Full article

The long-term inhalation of free silica dust causes silicosis—a prevalent occupational hazard—yet its systemic effect on male reproductive toxicity remains underexplored. Tetrandrine (Tet) is the only plant-derived anti-silicosis drug approved in China. This study investigates silica (SiO₂) -induced male reproductive damage and evaluates Tet’s protective effects. Sixty male C57BL/6 mice (6–8 weeks) were divided into control, SiO₂ exposure, and SiO₂ + Tet groups. SiO₂ was administered via intranasal infusion and Tet via gavage. Mice were sacrificed at day 7 (male reproductive injury model corresponding to the pulmonary inflammation stage) and day 42 (male reproductive injury model corresponding to the pulmonary fibrosis stage). Analyses included sperm morphology, testicular transcriptome sequencing, RT-qPCR, and immunofluorescence. At day 7, SiO₂ exposure upregulated testicular inflammatory markers, which were partially mitigated by Tet. At day 42, SiO₂ increased sperm deformity and testicular fibrosis markers (fibronectin and vimentin); Tet intervention reduced these abnormalities. Transcriptome analysis revealed distinct gene expression patterns at day 7 versus day 42, indicating time-dependent injury mechanisms. Tetrandrine alleviates silica-induced reproductive damage in male mice, suggesting potential therapeutic applications for occupational silica exposure and expanding the understanding of silica toxicity beyond the respiratory system. Full article

Tibetan sheep, a dominant livestock species on the Qinghai–Tibet Plateau, is characterized by late sexual maturity and low reproductive efficiency. Although long non-coding RNAs (lncRNAs) are known to play critical regulatory roles in mammalian testicular development and spermatogenesis, their expression dynamics and functions in Tibetan sheep remain poorly understood. In this study, we integrated histological and transcriptomic analyses to profile testicular lncRNAs across three developmental stages: pre-pubertal (3 months), sexually mature (1 year), and adult (3 years). Histological examination showed progressive structural maturation of seminiferous tubules, accompanied by significant increases in testicular weight and serum testosterone levels. RNA sequencing identified 10,857 high-confidence lncRNAs and uncovered extensive reprogramming of the lncRNA transcriptome during sexual maturation, with 7784 lncRNAs differentially expressed between pre-pubertal and post-pubertal stages. Functional enrichment analyses of cis- and antisense-target genes indicated that these lncRNAs were involved in key biological processes, including cell cycle regulation, TGF-β and Hippo signaling pathways, extracellular matrix organization, glycolysis, and apoptosis. Co-expression network analysis further linked upregulated lncRNAs to spermatogenesis-related genes involved in processes such as sperm nuclear condensation (e.g., TNP1) and metabolic support (e.g., PFKP). Our findings demonstrated that lncRNAs coordinate testicular development and spermatogenesis in Tibetan sheep by modulating transcriptional networks, remodeling the cellular microenvironment, and reprogramming energy metabolism. This study provides the first comprehensive atlas of testicular lncRNAs in Tibetan sheep and offers novel insights into the epigenetic regulation of male reproduction in high-altitude mammals. Full article

During the development of the gametophyte in angiosperms, a series of processes occurs, including pollination, pollen recognition, adhesion, hydration, germination, pollen tube growth, and the guidance of the pollen tube toward the ovule for the delivery of sperm cells to the female gametophyte. These processes require a substantial energy supply, which is provided by cellular respiration in the plant. Throughout this sequence, the generation of reactive oxygen species (ROS) is concomitantly observed. At present, the mechanisms underlying ROS production remain incompletely understood, especially in plant trees such as Salix linearistipularis. In this study, pistils of S. linearistipularis were used as experimental materials, and pistils were divided according to their development into three stages—S1, S2, and S3. Transcriptome sequencing (RNA-Seq) was performed for the three developmental stages, and the results indicated that metabolic pathways associated with oxidoreductase activity were highly significant during pistil development in S. linearistipularis. During pistil development, the levels of ROS accumulated rapidly. After pollination, with the adhesion and germination of pollen, the levels of ROS decreased significantly. Moreover, bidirectional regulation of ROS levels revealed that treatment with ROS inducers and scavengers led to increased and decreased ROS accumulation, which were accompanied by the inhibition and promotion of pollen tube number and length. These two opposite results indicate that ROS are the key factor regulating pistil development and pollen tube germination in S. linearistipularis. Full article

Grass carp (Ctenopharyngodon idella) is one of the most economically important cyprinid species cultured in China. The diploid gynogenetic grass carp (2nGGC, 2n = 48) was generated from the hybrid of female grass carp (GC, 2n = 48) and male topmouth culter (TC, 2n = 48, Culter alburnus). This study obtained the full-length transcriptome of 2nGGC from five tissues using Pacific Biosciences (Pacbio) single-molecule real-time long-read isoform sequencing. Following the mapping of long reads to GC and TC reference genomes, a total of 1848 fusion isoforms were identified. Among them, 775 were distributed across different genomes, indicating that chimeric DNA fragments of TC were embedded in the 2nGGC genome. After removing the fusion genes and redundant isoforms, 107,721 full-length transcripts were obtained from 2nGGC, providing important full-length reference sequences for further research. Finally, comparative analysis of homologous gene variation identified 34 fragments in 2nGGC containing recombinant SNPs derived from both GC and TC. These results provide evidence that natural gynogenesis represents a form of “micro-hybridization” characterized by heterogeneous DNA fragments, distinct from traditional hybridization involving chromosome-level recombination. These findings offer valuable reference for fish genetic breeding. Full article

Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, poses a significant threat to male reproductive health, but the underlying latent molecular mechanisms remain virtually unknown. This study investigated the effects of embryonic B[a]P exposure on testicular function and spermatogenesis in F0 and F1 adult male medaka (Oryzias latipes). Embryos were exposed to sublethal concentrations (2.5, 20, and 80 μg/L) for 8 days and then raised in clean water until they reached adulthood. Transcriptomic analysis of F0 testicular tissues revealed widespread dysregulation of critical pathways. Exposure impaired the brain–pituitary–gonadal axis by disrupting GnRH signaling and downregulating genes encoding key steroidogenic enzymes (CYP17A1, HSD3B2), indicating suppressed testosterone biosynthesis. Concurrently, pathways essential for cellular energy metabolism (AMPK signaling, insulin signaling), amino acid biosynthesis, and cytoskeletal organization (actin cytoskeleton, focal adhesion) were profoundly altered. Furthermore, B[a]P activated apoptotic pathways and disrupted the balance between cell survival (PI3K-Akt signaling) and death, compromising spermatogenic cell fate. These molecular disruptions manifested in drastic physiological impairments, including a reduced gonadosomatic index, decreased sperm motility, and compromised fertilization success in F0 males, although these effects were recovered in the F1 generation. This study provides a comprehensive molecular basis for the long-term reproductive toxicity of early-life B[a]P exposure. Full article

Numerous factors, including genetic, environmental, and nutritional, are involved in testicular development and spermatogenesis. However, little is known about the effects of seasonal factors on pre-sexual maturity testicular development in Hu rams, which are famous for their high fertility and year-round estrus onset. This study explored the effect of the birth season on testicular development and spermatogenesis in Hu sheep. Thirty-six 6-month-old male lambs born in summer (n = 18) and winter (n = 18) were selected for analysis. Results showed that summer-born lambs exhibited significantly higher cauda sperm density (102.65 ± 9.56 vs. 16.86 ± 2.02 × 10⁷/g), antioxidant indices such as superoxide dismutase (SOD: 6.29 ± 1.01 vs. 4.09 ± 0.25 U/mgprot), and higher expression levels of glutathione peroxidase 3 (GPX3), glutathione peroxidase 4 (GPX4), and copper/zinc superoxide dismutase (Cu/Zn-SOD) than winter-born lambs. Conversely, the malondialdehyde content (1.08 ± 0.32 vs. 2.13 ± 0.34 nmol/mgprot) was significantly lower in the summer-born group (p < 0.05) than in the winter-born group. A total of 44 differential oxylipins and 326 differentially expressed genes (DEGs) were screened by ultra-performance liquid chromatography–tandem mass spectrometry and transcriptomics, respectively. An integrated analysis of oxylipins and transcriptomics revealed that these differential molecules were enriched in metabolic pathways. Notably, downregulated DEGs (e.g., UAP1L1 and NAT8L) were significantly correlated with upregulated differential oxylipins (e.g., epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids). These results indicate that compared to the winter-born group, the testicular tissues of summer-born rams showed stronger testicular antioxidant capacity and lower lipid peroxidation at the sexual maturity stage, which contributes to spermatogenesis. Full article

Male infertility is a multifactorial condition often associated with disruptions in sperm metabolism and mitochondrial function, yet traditional semen analysis provides limited insight into these molecular mechanisms. Understanding sperm bioenergetics and metabolic dysfunctions is crucial for improving the diagnosis and treatment of conditions such as asthenozoospermia and azoospermia. This systematic review synthesizes recent literature, focusing on advanced tools and techniques—including omics technologies, advanced imaging, spectroscopy, and functional assays—that enable comprehensive molecular assessment of sperm metabolism and development. The reviewed studies highlight the effectiveness of metabolomics, proteomics, and transcriptomics in identifying metabolic biomarkers linked to male infertility. Non-invasive imaging modalities such as Raman and magnetic resonance spectroscopy offer real-time metabolic profiling, while the seminal microbiome is increasingly recognized for its role in modulating sperm metabolic health. Despite these advances, challenges remain in clinical validation and implementation of these techniques in routine infertility diagnostics. Integrating molecular metabolic assessments with conventional semen analysis promises enhanced diagnostic precision and personalized therapeutic approaches, ultimately improving reproductive outcomes. Continued research is needed to standardize biomarkers and validate clinical utility. Furthermore, these metabolic tools hold significant potential to elucidate the underlying causes of previously misunderstood and unexplained infertility cases, offering new avenues for diagnosis and treatment. Full article

To achieve the goals of productivity and sustainability across diverse livestock systems, reproductive factors play a pivotal role. Historically, reproductive research has primarily focused on females, as they are responsible for maintaining pregnancy and delivering offspring following oocyte fertilization. However, since the early 2000s, the biological significance of sperm RNAs has been increasingly recognized in various livestock species. These RNAs contribute both genetically and epigenetically at the time of fertilization and during early embryonic development. Multiple types of sperm RNA have been identified in bovine, porcine, ovine, buffalo, and caprine spermatozoa. Notably, transcriptomic profiling has shown potential to differentiate between high- and low-fertility males, even when conventional semen quality values appear normal in both groups. This opens the possibility for more accurate identification of highly fertile sires. Nevertheless, a definitive marker or set of markers has yet to be established, likely due to the transcriptome’s sensitivity to environmental conditions and to the variability in evaluation methodologies. Therefore, global scientific efforts should aim to establish standardized, robust protocols, as sperm RNA represents a promising avenue for enhancing the sustainability of animal production systems. Full article

Background: Oxidative stress is a critical factor contributing to male infertility, impairing spermatogonial stem cells (SSCs) and disrupting normal spermatogenesis. This study aimed to isolate and characterize human SSCs and to investigate oxidative stress-related gene expression, protein interaction networks, and developmental trajectories involved in SSC function. Methods: SSCs were enriched from human orchiectomy samples using CD49f-based magnetic-activated cell sorting (MACS) and laminin-binding matrix selection. Enriched cultures were assessed through morphological criteria and immunocytochemistry using VASA and SSEA4. Transcriptomic profiling was performed using microarray and single-cell RNA sequencing (scRNA-seq) to identify oxidative stress-related genes. Bioinformatic analyses included STRING-based protein–protein interaction (PPI) networks, FunRich enrichment, weighted gene co-expression network analysis (WGCNA), and predictive modeling using machine learning algorithms. Results: The enriched SSC populations displayed characteristic morphology, positive germline marker expression, and minimal fibroblast contamination. Microarray analysis revealed six significantly upregulated oxidative stress-related genes in SSCs—including CYB5R3 and NDUFA10—and three downregulated genes, such as TXN and SQLE, compared to fibroblasts. PPI and functional enrichment analyses highlighted tightly clustered gene networks involved in mitochondrial function, redox balance, and spermatogenesis. scRNA-seq data further confirmed stage-specific expression of antioxidant genes during spermatogenic differentiation, particularly in late germ cell stages. Among the machine learning models tested, logistic regression demonstrated the highest predictive accuracy for antioxidant gene expression, with an area under the curve (AUC) of 0.741. Protein oxidation was implicated as a major mechanism of oxidative damage, affecting sperm motility, metabolism, and acrosome integrity. Conclusion: This study identifies key oxidative stress-related genes and pathways in human SSCs that may regulate spermatogenesis and impact sperm function. These findings offer potential targets for future functional validation and therapeutic interventions, including antioxidant-based strategies to improve male fertility outcomes. Full article

In addition to the male genome, the fertilizing spermatozoon delivers to the oocyte several factors whose deficiency can cause embryo dysfunction. Sperm oocyte-activating factor, identified as phoshoplipase C zeta (PLCζ), drives oocyte exit from meiotic arrest through a signaling pathway initiated by periodic rises of free cytosolic Ca²⁺ concentration (calcium oscillations). Sperm centrioles, together with oocyte proteins, form centrosomes that are responsible for aster formation, pronuclear migration, and DNA polarization before nuclear syngamy and subsequent mitotic divisions. Sperm DNA fragmentation can be at the origin of aneuploidies, while epigenetic issues, mainly abnormal methylation of DNA-associated histones, cause asynchronies of zygotic gene activation among embryonic cells. Sperm long and short non-coding RNAs are important epigenetic regulators affecting critical developmental processes. Dysfunction of sperm PLCζ, centrioles, DNA, and RNA mostly converge to aneuploidy, developmental arrest, implantation failure, miscarriage, abortion, or offspring disease. With the exception of DNA fragmentation, the other sperm issues are more difficult to diagnose. Specific tests, including heterologous human intracytoplasmic sperm injection (ICSI) into animal oocytes, genetic testing for mutations in PLCZ1 (the gene coding for PLCζ in humans) and associated genes, and next-generation sequencing of sperm transcriptome, are currently available. Oral antioxidant treatment and in vitro selection of healthy spermatozoa can be used in cases of sperm DNA fragmentation, while ICSI with assisted oocyte activation is useful to overcome oocyte-activation defects. No clinically confirmed therapy is yet available for sperm RNA issues. Full article

The Junggar Bactrian camel, a primitive indigenous breed in China, exhibits low reproductive efficiency under natural grazing conditions. This is partly attributed to the development of the epididymis and the quality of semen, both of which directly affect reproductive performance. The epididymis is a key male reproductive organ responsible for sperm storage and transport. However, the gene expression profile of camel epididymal tissue remains poorly understood. In this study, we conducted whole-transcriptome sequencing of epididymal tissues from Junggar Bactrian camels before and after sexual maturity. A total of 683 differentially expressed mRNAs (DEmRNAs) were identified, including TPM2, ITGA5, FASN, and ACP5, of which 415 were upregulated and 268 were downregulated. Additionally, 260 differentially expressed long non-coding RNAs (DELncRNAs), including LOC123611838, LOC105083505, and LOC123614702, were identified, with 113 upregulated and 147 downregulated. An additional 11 differentially expressed microRNAs (DEmiRNAs), including eca-miR-206 and eca-miR-216a, were also detected. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that key differentially expressed genes (DEGs), including TPM2, ITGA5, DDIT4, FASN, and ACP5, were mainly involved in pathways such as Cell Adhesion Molecules, Phospholipase D signaling, Cytokine–Cytokine Receptor Interaction, and Olfactory Transduction. This study presents a comprehensive whole-transcriptome analysis of the epididymis in Junggar Bactrian camels before and after sexual maturity, identifying key genes and regulatory pathways associated with epididymal development and reproductive function. These findings provide a theoretical foundation and valuable data for future research on reproductive performance and epididymal biology in Bactrian camels. Full article