Search Results (1,140)

In vitro maturation (IVM) of oocytes is a critical initial step in mammalian in vitro production (IVP), and its quality directly influences the developmental competence of subsequent embryos. Oxidative stress is a major constraint on oocyte quality, which can be mitigated by exogenous antioxidants. In this study, porcine oocytes were matured in IVM medium supplemented with the antioxidant N-acetyl-L-cysteine (NAC; 0, 0.5, 1.5, and 4 mM) to evaluate its effects on maturation rate, antioxidant capacity, mitochondrial function, vitrification–warming survival rate, post-warming ROS levels, and early embryonic developmental rate. To elucidate the molecular mechanisms underlying the effects of NAC on porcine oocyte maturation, we conducted single-cell transcriptome sequencing. The results showed that, versus the control, 1.5 mM NAC substantially enhanced the IVM rate (p < 0.05), reduced ROS levels (p < 0.05), and increased mitochondrial activity, as assessed by MitoTracker, mitochondrial membrane potential (MMP), and ATP content (p < 0.05). These results suggest that 1.5 mM NAC relieves oxidative stress in oocytes and improves mitochondrial function. However, NAC addition showed no significant differences in vitrification–warming survival rate and post-warming ROS levels relative to the control group (p > 0.05). In addition, 1.5 mM NAC markedly improved the cleavage rate and blastocyst rate of porcine oocytes after in vitro fertilization (IVF, p < 0.05), and also enhanced the cleavage rate after parthenogenetic activation (PA, p < 0.05). Single-cell transcriptome sequencing revealed that, versus the control, differentially expressed genes (DEGs) identified after 1.5 mM NAC supplementation were mainly enriched in pathways related to oxidative phosphorylation (OXPHOS), spliceosome, and ubiquinone/terpenoid-quinone biosynthesis. Among these, the OXPHOS pathway showed the most significant enrichment, with upregulated expression of pathway-related genes such as COX6C, CYCS, and SDHD. The accuracy of the transcriptomic results was further validated by qPCR. In conclusion, supplementing with 1.5 mM NAC relieved oxidative stress, improved mitochondrial function, and thereby promoted oocyte maturation and improved oocyte quality, ultimately facilitating subsequent IVF early embryonic development. Full article

Urban particulate matter (UPM) is a major environmental pollutant known to induce systemic inflammation. While its respiratory toxicity is well-documented, the potential vulnerability of the female reproductive system to inhaled UPM remains a critical concern. In this study, we evaluated female reproductive outcomes in a murine model following repeated short-term intratracheal instillation of UPM (40–200 mg/kg) for a month. Our results demonstrate that while UPM exposure induced robust, dose-dependent pulmonary inflammation, characterized by immune cell infiltration (CD45+, F4/80+, and Ly6G+) and upregulation of pro-inflammatory (Il-6, Il-1β, and Tnfα) and fibrotic (Col1a1 and Tgfβ1) markers, no apparent adverse effects were observed in the reproductive endpoints examined. No significant alterations were observed in maternal pregnancy outcomes, including oocyte recovery rates, fertilization competence, gestation duration, litter size, and postnatal development of pups. Furthermore, the mRNA expression of inflammatory markers in the ovaries and uteri was not detectable. Direct in vitro exposure of two-cell embryos to UPM did not interfere with preimplantation embryo development. Although benzanthracene slightly reduced the blastocyst formation rate, UPM and polycyclic aromatic hydrocarbons, major toxic components of UPM, did not severely compromise preimplantation embryo development in vitro. In conclusion, these findings suggest that marked UPM-induced pulmonary inflammation is not accompanied by substantial alterations in the female reproductive outcomes examined under short-term exposure conditions. Full article

Successful embryo development transpires far before fertilization inside the meticulously regulated microenvironment of the ovarian follicle. Increasing data indicates that circadian regulatory systems influence several processes that define oocyte competence, including mitochondrial activity, oxidative balance, meiotic development, and cellular metabolism. Brain and muscle ARNT-like protein 1 (BMAL1), an essential transcription factor in circadian regulation, has garnered significant interest due to its crucial involvement in ovarian physiology and reproductive function. Dysregulated BMAL1 signaling has been linked to compromised folliculogenesis, diminished steroidogenesis, mitochondrial dysfunction, elevated oxidative stress, and irregularities in meiotic spindle organization, all of which may negatively impact oocyte quality and early embryo development. Recent experimental and clinical findings indicate that results of assisted reproduction may be influenced by circadian disruption, sleep problems, obesity, ageing, and metabolic dysfunction. Full article

In this study, targeted metabolomics and transcriptomics were applied for the first time to compare fatty acid contents, vitamin levels, and gene expression profiles between Stage II and Stage IV ovaries of LBG. The data revealed a rise in total SFA and PUFA as the ovary progressed from Stage II to Stage IV. The marked increase in n-3 PUFA from 11.5% in Stage II to 26.8% in Stage IV ovaries was primarily attributed to DHA. Despite a reduction in n-6 PUFA, ARA and its metabolism-related fatty acids all increased, suggesting indispensable roles for both ARA and DHA in the vitellogenesis of LBG. Consistent with the changes in fatty acid profiles during ovarian maturation, transcriptome analysis revealed that many upregulated differentially expressed genes (DEGs) showed significant enrichment in fatty acid biosynthesis, arachidonic acid metabolism, and steroid hormone synthesis pathways. The concentrations of VC and VE increased, whereas VA declined during ovarian development from Stage II to Stage IV. Accordingly, many upregulated DEGs exhibited significant enrichment in ascorbate and aldarate metabolism, as well as vitamin digestion and absorption pathways. In addition to VC and VE, our transcriptome data also highlighted the importance of several B vitamins in oocyte development of LBG, warranting further investigation. Overall, these findings suggest that DHA, ARA, VC, and VE are key nutrients governing oocyte maturation in LBG. This study provides a solid theoretical basis for developing broodstock nutritional enhancement strategies in the artificial propagation of LBG. Full article

To compare the fatty acid composition in different tissues of Anguilla japonica before and after sea entry, we analyzed the muscle, liver, and ovary of eels from the Yangtze Estuary and offshore waters, and describe the distribution patterns of various fatty acids in different tissues. Comparing different tissues, in eels from the estuary, the muscle had the highest content of EPA, the liver had the highest content of DHA, and the ovary had the highest contents of ARA. In offshore eels, the muscle had the highest contents of C16:1 and C18:1n9c; the liver had the highest content of C16:0; and the ovary had the highest contents of C18:0 and DPA3. Comparing eels before and after sea entry, the contents of C14:0, C16:0, C20:1n9 and C20:2 in the ovary of estuary eels were significantly higher than those in the offshore eels. Conversely, the contents of C18:0, C20:0, DPA3, HUFA, total n3-PUFA and n3/n6 ratio in the ovary of offshore eels were significantly higher than those in estuary eels. Ovaries of estuarine eels showed higher proportions of saturated fatty acids, whereas ovaries of offshore eels showed higher proportions of n3-PUFA. The observed differences in ovarian fatty acid profiles may reflect the nutritional demands associated with gonadal development stages, which were determined by histological oocyte staging. Full article

Bisphenols and phthalates are ubiquitous endocrine-disrupting chemicals with potential effects on reproductive neuroendocrine regulation, particularly during sensitive developmental windows. This review summarizes current evidence on their exposure profile, mechanisms of reproductive disruption, and female- and male-specific reproductive adversities. A structured narrative review was conducted using PubMed/MEDLINE, Scopus, and Web of Science, including experimental, epidemiological, biomonitoring, systematic review, and meta-analytic studies addressing bisphenols, phthalates, fertility, hormonal regulation, gametogenesis, pregnancy outcomes, and reproductive toxicity mechanisms. Bisphenols and phthalates interfere with estrogenic and androgenic signaling, hypothalamic–pituitary–gonadal axis regulation, steroidogenesis, oxidative stress, inflammation, apoptosis, mitochondrial function, and epigenetic regulation. Reported outcomes include impaired ovarian function, altered oocyte development, hormonal imbalance, reduced semen quality, defective spermatogenesis, sperm DNA damage, infertility, and adverse developmental or pregnancy-related effects. However, human evidence remains heterogeneous and limited by observational designs, exposure misclassification, residual confounding, and insufficient mixture assessment. Current evidence supports biological plausibility for bisphenol- and phthalate-related reproductive toxicity, but causal inference remains limited. Prospective studies with repeated biomonitoring, standardized reproductive endpoints, sex- and age-specific analyses, and improved mixture modeling are needed. A precautionary reduction in avoidable exposure appears reasonable, particularly during sensitive reproductive and developmental periods. Full article

Gametocyte-specific factor 1 (Gtsf1) plays a pivotal role in the gonadal development by transposon silencing via the piRNA pathway in Drosophila melanogaster and Bombyx mori, and is implicated in the female sex determination in B. mori. However, its function remains elusive in other insect species, including Plutella xylostella, a highly destructive pest in cruciferous crops. In this study, we characterized PxGtsf1, encoding a 27.84 kDa protein containing two conserved U11-48K-like CHHC zinc-finger domains. PxGtsf1 was predominantly expressed in male pupae, males and testes. Using CRISPR/Cas9 technique, we successfully generated a homozygous PxGtsf1-knockout strain (△PxGtsf1) with 11 bp deletion. △PxGtsf1 females exhibited normal morphology in terms of external genitalia, body weight, ovariole morphology, ovariole length, oocytes number, and internal ovarian structure, and maintained the expression levels of genes related to female sex determination and fertility. In contrast, △PxGtsf1 males displayed reduced testis size and enlarged eupyrene sperm bundles, whereas apyrene sperm bundles appeared normal. Wild-type (WT) or △PxGtsf1 females mated with △PxGtsf1 males had significantly smaller bursa copulatrix distention area compared to those mated with WT males. Furthermore, WT or △PxGtsf1 females mated with △PxGtsf1 males produced significantly fewer eggs with lower hatching rates than those mated with WT males. Co-immunoprecipitation assays revealed that PxGtsf1 specifically interacts with PxPiwi. Small RNA sequencing further showed that PxGtsf1 knockout resulted in transposon dysregulation in the testes without affecting overall piRNA abundance, suggesting that PxGtsf1 functions in piRNA-mediated transposon regulation rather than global piRNA biogenesis. PxGtsf1 is first reported to be specifically required for male fertility in Lepidoptera insects but is dispensable for female sex determination., PxGtsf1 regulates transposon homeostasis without affecting global piRNA biogenesis. These findings provide new insights into the diverse functions of Gtsf1 in Lepidopteran insects. Full article

Background and Clinical Significance: The oocyte zona pellucida (ZP) is an extracellular glycoprotein matrix with essential roles in oogenesis, fertilization, and early embryonic development. Abnormal ZP morphology is associated with female infertility and adverse outcomes after assisted reproductive technology (ART), but its molecular basis remains incompletely understood. Case Presentation: We present three patients with female infertility, abnormal oocyte ZP morphology, and adverse embryological outcomes, including fertilization failure and early developmental arrest. Whole-genome sequencing identified an extremely rare heterozygous missense variant in the ZP4 gene (rs1254095560) in one patient, resulting in the p.Leu342Pro substitution at a conserved amino acid position within the functionally important ZP-C subdomain of the protein. In silico modeling showed that the p.Leu342Pro substitution may alter the spatial folding of the ZP4 protein. Conclusions: These results and the known role of ZP4 in the organization of the zona pellucida allow this variant to be considered a candidate genetic factor potentially associated with disruption of the zona pellucida structure. The absence of comparable, apparently pathogenic coding variants in ZP genes in two other patients with a similar zona pellucida phenotype suggests genetic heterogeneity of this phenotype. Full article

Paternal contributions to preimplantation embryo development are increasingly recognized as an important component of reproductive success, but the associations between male reproductive phenotype, early embryonic competence, and embryo molecular characteristics remain insufficiently defined. Using bovine in vitro embryo production as a translational large-mammalian model, this study evaluated whether paternal reproductive phenotype and oocyte origin were associated with embryo developmental performance and embryonic sirtuin expression. Oocytes obtained from mature cows or heifers were fertilized with semen from bulls differing in reproductive status, including bulls characterized by libido disturbances and irregular semen collection. Fertilization, cleavage, blastocyst formation, and hatching were assessed, while embryonic SIRT2, SIRT3, SIRT6, and SIRT7 expression was quantified by immunofluorescence. Early developmental endpoints were relatively preserved, whereas differences were more evident at later stages of preimplantation development. Cow-derived oocytes were associated with higher hatching rates than heifer-derived oocytes. Embryos generated using semen from bulls with an impaired reproductive phenotype showed lower developmental competence and lower SIRT6 and SIRT7 expression. SIRT6 expression showed the strongest positive correlation with hatching, and positive correlations were also observed among the analyzed sirtuins. These findings indicate that paternal reproductive phenotype and oocyte origin are associated with bovine embryo developmental competence and embryonic sirtuin profiles. Embryonic SIRT6 and SIRT7 expression may represent candidate molecular indicators of embryo competence; however, causal relationships cannot be inferred from the present study design. Full article

Recent developments and applications of high-throughput omics technologies have modernised animal biotechnology, offering extraordinary comprehension of animal reproduction. The current review discusses the applications and advancement of high-throughput omics technologies in animal reproductive biology. The data for this review were sourced from old and recently published work in different journals. The internet databases used to access the manuscripts were ResearchGate, Google Scholar, ScienceDirect, Web of Science, PubMed, and the Directory of Open Access Journals. The results showed that omics technologies have been previously used in human biology, and with time, have come to be introduced in animal reproductive biology. Studies using these technologies showed that genomics analysis identified at least 180 CNVs and 49 candidate genes enriched in vital fertility pathways, including retinol metabolism, steroid hormone biosynthesis, and Hippo signalling, while transcriptomics analysis screened the molecular dynamics of reproductive indicators at both the cellular and molecular levels. Pig oocytes matured in vitro or in vivo were subjected to transcriptome analysis. These analyses generate large amounts of ‘Big Data’. As a result, omics can handle large amounts of data generated through the analyses, but it needs bioinformatics experts and advanced computers, making it less affordable at the farm level. However, widely utilised technologies, including assisted reproductive technologies (ARTs), have hit their limit after years of use. To break this plateau of traditional ARTs, future research must give integrative ARTs and high-throughput omics technologies top priority, as they have clearly been shown to improve farm animals’ reproductive success. The synergy of increased reproductive efficiency and a smaller ecological footprint is crucial for improving the accuracy and sustainability of livestock systems, ultimately promoting global food security. Full article

Integrated proteomics and untargeted metabolomics were employed to systematically characterize molecular differences between Acipenser schrenckii embryos with normal versus abnormal 24 h post-fertilization (24 hpf), which were classified as high-quality (HQ) and poor-quality (PQ) groups. Among 1636 proteins and 1102 metabolites, 220 differentially expressed proteins (DEPs) and 365 differential metabolites (DMs) were identified. Functional enrichment demonstrated that HQ samples were predominantly enriched in pathways associated with amino acid biosynthesis, glycolysis/tricarboxylic acid cycle, nucleotide metabolism, and mRNA surveillance, which collectively supported material accumulation, energy supply, and embryonic developmental competence. In contrast, PQ samples were mainly enriched in oxidative phosphorylation, mitochondrial stress response, arachidonic acid metabolism, and immune and inflammatory signaling pathways, indicating severe lipid metabolic disorders and excessive oxidative stress. Spearman correlation analysis identified L-pyroglutamic acid and ascorbic acid as core correlated metabolic hubs associated with high-quality eggs, while natamycin and tetrahydrocorticosterone were correlated characteristic metabolic signatures enriched in deteriorated eggs. Key protein nodes showing strong correlations with 24 hpf developmental phenotypes included GAPDH, glutathione S-transferase, and CYP450 2E1. Collectively, this study reveals divergent correlated molecular profiles linked to normal versus abnormal 24 hpf development and screens correlative multi-omics candidate signatures for distinguishing well-developed and deteriorated oocytes. Full article

Alepes djedaba is a coastal fish species of high economic value. However, information on its early developmental biology remains incomplete, which limits its application in large-scale seed production. In this study, fertilized eggs were obtained through hormone-induced spawning. Under controlled conditions, microscopic observation and histological sectioning were used to systematically record and analyze embryonic development, larval growth characteristics, and the gonadal development potential of the artificially bred first-generation (F1) offspring. The results showed that the fertilized eggs of A. djedaba are spherical and pelagic with a single oil globule. The egg diameter is (672.02 ± 10.03) μm, and the oil globule diameter is (189.76 ± 8.82) μm. At a water temperature of 24.50–24.97 °C, embryonic development is divided into 6 periods (20 stages), taking 19 h 28 min to complete hatching with an average hatching rate of 22.9% ± 15.6%. The total length of newly hatched larvae is (1.43 ± 0.09) mm, with an average daily growth of 0.39 mm from 0 to 21 days post-hatching (DPH). Furthermore, the testes of the F1 generation cultured in captivity exhibit complete tissue structures and mature spermatozoa, while the ovaries show orderly development primarily dominated by stage II–III oocytes with some early stage IV oocytes. This confirms at the histocytological level that the artificially bred offspring possess normal gonadal development, providing strong evidence of its reproductive potential. This study clarifies the key stages of early development and the adaptability of A. djedaba in captive environments, providing critical theoretical support and basic data for subsequent large-scale seed production and larval rearing optimization. Full article

Oocyte development begins during embryonic life and remains arrested in prophase I until meiotic resumption during ovulation. A substantial proportion of oocytes retrieved during assisted reproductive procedures remain immature at the metaphase I (MI) stage and fail to achieve the maturation required for fertilization. In women with diminished ovarian reserve, alterations in the ovarian microenvironment may impair the biochemical signaling necessary for normal oocyte development. Autologous exosomes have emerged as a potential strategy to enhance meiotic progression through the transfer of bioactive molecules. This study aimed to evaluate the in vitro efficacy of autologous exosomes in improving the maturation potential of immature oocytes in women with diminished ovarian reserve. A prospective, randomized, controlled pilot study was conducted in 32 women aged 38–46 years. A total of 111 oocytes were retrieved (52 metaphase II [MII] and 59 MI oocytes), and only MI oocytes were included in the experimental analysis. MI oocytes were cultured either in conventional medium or in medium supplemented with autologous exosomes. The exosome-supplemented group demonstrated significantly higher in vitro maturation rates compared with the conventional culture group (63.63% vs. 11.53%; p < 0.001). Fertilization rates among matured oocytes were 76.19% and 33.33% in Groups II and I, respectively. In addition, favorable embryo development outcomes were observed in the exosome-treated group. Autologous exosome supplementation may enhance in vitro maturation and fertilization outcomes in women with diminished ovarian reserve. After accounting for clustering of oocytes within patients using generalized estimating equations, exosome supplementation remained significantly associated with successful oocyte maturation (OR 15.46, 95% CI 5.16–46.39; p < 0.001). Full article

Sire-dependent variation in bovine in vitro fertilization (IVF) success is poorly explained by conventional semen parameters once samples meet standard quality thresholds. Sperm capacitation is required for acquisition of fertilization competence, yet its contribution to sire-dependent variation in bovine IVF outcomes remains unclear. Fifteen bulls (Bos taurus) were evaluated across five IVF replicates using 30 abattoir-derived oocytes per bull per replicate. Sperm were analyzed before (0 h) and after 3 h of in vitro capacitation using image-based flow cytometry to quantify zinc ion localization patterns (zinc signatures; Fluo-Zin 3 AM), acrosome remodeling (peanut agglutinin conjugated to Alexa Fluor 647; PNA-AF647), and plasma membrane integrity (propidium iodide). Motility parameters were assessed using computer-aided sperm analysis (CASA). Cleavage rate was assessed on Day 3 and blastocyst development on Day 7. Substantial bull-to-bull variation was observed for both cleavage (31.5–76.3%) and blastocyst development (7.3–40%). Bull effects on cleavage were significant (p < 0.0001). Predictive modeling revealed that CASA or biomarker variables alone explained limited variance in embryo development. In contrast, models incorporating capacitation-induced changes in zinc signatures and acrosome remodeling significantly improved prediction of IVF outcomes. Integration of biomarker and motility parameters across time points yielded the highest explanatory power, with zinc signature dynamics among the most consistently informative predictors. These findings demonstrate that sperm capacitation-associated zinc flux and acrosomal remodeling are biologically relevant determinants of bull-specific variation in bovine IVF embryo development and provide mechanistic biomarkers that improve prediction beyond conventional motility assessment alone. Full article

Obesity is a multifactorial condition that profoundly affects female reproductive health through endocrine, metabolic, and inflammatory mechanisms that disrupt the hypothalamic–pituitary–gonadal (HPG) axis. Women with obesity frequently develop menstrual irregularities, anovulation, amenorrhea, infertility, polycystic ovary syndrome (PCOS), impaired endometrial receptivity, and adverse pregnancy outcomes. Central obesity and insulin resistance contribute to hyperinsulinemia, reduced sex hormone-binding globulin (SHBG) levels, hyperandrogenism, altered gonadotropin secretion, and impaired folliculogenesis, while adipokines such as leptin and chronic inflammation further impair ovarian steroidogenesis and ovulatory function. Obesity-related oxidative stress and lipotoxicity also negatively affect oocyte quality, embryo development, implantation, and assisted reproductive technology outcomes, increasing the risk of gestational diabetes, preeclampsia, miscarriage, and preterm birth. This review evaluates the therapeutic potential of pharmacological weight-loss therapies in obesity-associated female reproductive dysfunction. A comprehensive literature review was conducted using various databases, focusing on anti-obesity pharmacotherapy on obesity, infertility and fertility in reproductive-aged women. Evidence suggests that several FDA-approved and off-label anti-obesity agents, including orlistat, liraglutide, semaglutide, phentermine/topiramate, bupropion/naltrexone, metformin, exenatide, and tirzepatide, may improve reproductive outcomes primarily indirectly through weight reduction and metabolic improvement. GLP-1 receptor agonists, particularly liraglutide, semaglutide, and exenatide, appear especially promising, demonstrating beneficial effects on insulin sensitivity, menstrual regularity, ovulation, androgen levels, and pregnancy rates in women with PCOS. Tirzepatide, a dual GLP-1/GIP receptor agonist, has shown potent weight-loss and metabolic effects with potential indirect fertility benefits. Metformin improves insulin sensitivity and is widely used in PCOS to regulate androgen levels and restore ovulation, although its effects on pregnancy and live birth rates remain controversial. However, evidence for several agents remains limited, and concerns persist regarding reproductive safety during pregnancy. Overall, anti-obesity pharmacotherapy may represent an important adjunctive strategy for improving reproductive and metabolic health in women with obesity, although larger randomized clinical trials are still required. Full article