Search Results (951)

The successful application of assisted reproductive technologies (ARTs), such as in vitro maturation (IVM) and artificial oocyte activation, requires species-specific adaptations. Although these methods are routinely used in laboratory rodents, their use in wild or non-model species remains limited, such as the Spix’s yellow-toothed cavy, a Neotropical species of ecological and reproductive interest. This study evaluated the effects of different concentrations of epidermal growth factor (EGF; 10 or 50 ng/mL) on IVM (Experiment 1) and of 6-dimethylaminopurine (6-DMAP) on artificial oocyte activation (Experiment 2). EGF at 10 ng/mL (93.8% ± 1.6; 84.9% ± 0.7) promoted greater viability and less apoptosis in cumulus cells, compared to 50 ng/mL (83.0% ± 1.6; 78.9% ± 2.7), maintaining cumulus expansion, ultrastructural integrity, and better morphometric quality of oocytes. Thus, this concentration was used in the next step, where oocytes were activated with or without 6-DMAP. After five days, the presence of 6-DMAP increased cleavage rates (69.3% ± 5.0) compared to activation without the compound (53.5% ± 3.5), without significantly affecting morula formation (13.2% ± 3.1 to 17.3% ± 2.9). It is concluded that EGF improves the oocyte microenvironment, while 6-DMAP enhances cleavage, with these being the initial steps in the development of ARTs for Spix’s yellow-toothed cavy. Full article

Normal proliferation of ovarian granulosa cells is essential for follicular development. The results of this study showed that ADAMTS1 was primarily localized in the cytoplasm of granulosa cells in sheep ovarian follicles, as revealed by immunohistochemistry and immunofluorescence staining. Knockdown and overexpression experiments of ADAMTS1 in granulosa cells demonstrated that the number of EdU-positive cells significantly decreased in the knockdown group (p < 0.05), while the expression levels of Bax (p < 0.05), Bax/Bcl2 (p < 0.01), and caspase3 (p < 0.05) were significantly upregulated, indicating that knockdown of ADAMTS1 markedly inhibited granulosa cell proliferation. In contrast, overexpression of ADAMTS1 significantly promoted cell proliferation. Transcriptome sequencing revealed that PSAT1 and SLC6A9 were significantly downregulated in the knockdown group and significantly upregulated in the overexpression group, which was confirmed by Quantitative Polymerase Chain Reaction (Q-PCR) (p < 0.05). KEGG enrichment analysis showed that PSAT1 was significantly enriched in the glycine, serine and threonine metabolism and vitamin B6 metabolism pathways. Molecular docking analysis indicated a stable binding interface between ADAMTS1 and PSAT1. Based on these findings, we speculate that ADAMTS1 may regulate amino acid metabolism in ovarian granulosa cells by modulating the expression of SLC6A9, which in turn affects PSAT1 in the glycine, serine, and threonine metabolism and vitamin B6 metabolism pathways, thereby influencing granulosa cell proliferation. Full article

The aim was to evaluate the effectiveness of semen cryopreservation and oocyte vitrification in roe deer as a potential method of gamete preservation for endangered deer species. Sperm were isolated from the cauda epididymis of fourteen bucks (n = 14). The motility measure (CASA) and morphology of fresh semen (FS) and frozen–thawed semen (TS) were compared. A hyaluronic binding assay was used to distinguish between mature FS spermatozoa expressing hyaluronan receptors and immature FS lacking these receptors, and the mitochondrial membrane potential (MMP) in TS was determined (flow cytometry). A Sperm–Hyaluronan Binding Assay (HBA) showed a viability rate of 61.9% in FS and 78.2% in TS. Oocytes received from eight does (n = 8) underwent a viability test and vitrification, and fresh oocytes from the other eight does (n = 8) were fertilized with TS and embryos were cultured until the blastocyst stage. The number of isolated oocytes, cumulus–oocyte complexes (COCs), cleaved embryos, and expanded blastocysts was evaluated. Higher percentages of morphological factors (acrosome, head, midpiece, and tail shape) were observed in FS compared to TS, whereas the motility and progressive movement were greater in TS (p ≤ 0.001). The viability was 50.5% and MMP was 40.6% in TS. A total of 311 oocytes were collected and from 150 COCs and 125 blastocysts developed. The viability of thawed oocytes after vitrification was 81%. The viability of vitrified oocytes and cryopreserved sperm confirmed the effectiveness of freezing protocols and highlights the potential for their implementation in other deer species. Full article

Background/Objectives: Platelet-derived growth factor receptor alpha (PDGFRα) is a receptor involved in cell growth and differentiation, with unclear roles in ovarian tissues and potential interactions with KCNK3 (potassium two-pore domain channel subfamily K member 3), a member of the two-pore domain K⁺ channel involved in cellular homeostasis. This study aims to map PDGFRα expression across mouse tissues and to explore its co-expression with KCNK3 in the ovary. Methods: We visualized PDGFRα expression using RNA-seq data from the genotype-tissue expression (GTEx) BodyMAP across 54 human tissues and Cap Analysis of Gene Expression (CAGE) data for various mouse tissues. In PDGFRα^EGFP mice expressing EGFP in PDGFRα⁺ cells, histological and fluorescence imaging were used to assess ovarian expression. Immunohistochemistry determined the co-localization of PDGFRα and KCNK3, and qPCR quantified their mRNA levels in the ovary, oviduct, and uterus. Results: PDGFRα showed high expression in human and mouse female reproductive tissues, particularly the ovary. In the PDGFRα^EGFP mouse model, PDGFRα was primarily found in the thecal layer and stromal cells, not in granulosa cells or oocytes. Immunohistochemistry indicated that 90.2 ± 8.7% of PDGFRα⁺ cells expressed KCNK3 in the ovarian stroma. qPCR revealed lower PDGFRα and KCNK3 expression in the ovary compared to the oviduct and uterus. Conclusions: This study shows that PDGFRα is predominantly expressed in ovarian stromal and theca cells and is highly co-localized with KCNK3, suggesting a potential role for PDGFRα⁺ cells in ionic regulation and their possible involvement in follicular development and ovarian physiology. Full article

To minimize the deleterious effects of oxidative stress and improve oocyte competence, we assessed the impact of melatonin during in vitro pre-maturation (pre-IVM) in bovine cumulus–oocyte complexes (COCs). We compared three groups: control (conventional IVM), pre-IVM control (without melatonin), and pre-IVM + MTn (with melatonin). The analyses included levels of reactive oxygen species (ROS), mitochondrial activity, oocyte lipid content, and the expression of genes related to oxidative stress and lipid metabolism in oocytes and cumulus cells. We also examined embryo quality by evaluating kinetics of development and gene expression. The pre-IVM + MTn group exhibited an increase (p ≤ 0.05) in ROS levels and a decrease (p ≤ 0.05) in lipid content, while maintaining mitochondrial activity similar (p > 0.05) to that of the control group. Regarding gene expression, the effect of pre-IVM, independent of melatonin, was characterized by a decrease in FABP3 transcripts in cumulus cells and reductions in GSS and NFE2L2 transcripts in oocytes (p ≤ 0.05). The pre-IVM + MTn group also displayed a decrease (p ≤ 0.05) in CAT and SOD2 transcript levels. In terms of embryonic development, the pre-IVM + MTn group achieved a higher blastocyst rate on D7 (p ≤ 0.05) compared to the control group (30.8% versus 25.8%), but with similar rates (p > 0.05) to the pre-IVM control group (30.8% versus 35.9%). However, there was a decrease in the levels of the PLAC8 transcript. This study indicates that, under the conditions tested, melatonin did not significantly benefit oocyte competence. Full article

Sperm count, motility, and morphology are semen parameters that directly affect male fertility. The presence of cytokines in seminal plasma negatively or positively influences these parameters. Interleukins and prostaglandins are proinflammatory cytokines present in human seminal plasma and play crucial roles in fertilization, in general and after intracytoplasmic sperm injection (ICSI) procedures. This study aimed to investigate the possible influence of interleukins IL-17 and IL-18, and prostaglandins PGE2 and PGF2α on male infertility. Semen samples were collected from 58 males who underwent the ICSI procedure. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of IL-17, IL-18, PGE2, and PGF2α, and these concentrations were then correlated with semen parameters and the rate of fertilization. Furthermore, the chromatin integrity of the sperm was evaluated with an Acridine Orange (AO) assay. The results showed an inversely proportional relationship between the AO binding intensity and fertilization rate (r = −0.394; p ≤ 0.002). Furthermore, a negative correlation was observed between the IL-18 concentration and positive AO (p ≤ 0.021). Moreover, the IL-18 concentration was positively correlated with the fertilization rate (p ≤ 0.05). In contrast, IL-17 did not significantly correlate with any semen parameters or with the fertilization rate. Seminal PGE2 levels were significantly correlated with embryo cleavage at 72 h (p ≤ 0.05). To conclude, this study revealed that denaturation of sperm nuclear deoxyribonucleic acid (DNA) contributes to low fertilization rates. In addition, this study proposed a potential role for IL-18 in fertilization. PGE2 likely influences embryo development, but further studies are needed to examine the impact of seminal PGE2 on the oocyte to fully elucidate its contribution to this complex biological process. Full article

This review aims to discuss how heat stress affects ovarian follicles and oocytes, steroidogenesis, and embryo development in ruminants. The literature shows that quiescent primordial follicles appear to be less susceptible to heat stress, but from the primary follicle stage onwards, they begin to suffer the consequences of heat stress. These adverse effects are exacerbated when the follicles are cultured in vitro. In antral follicles, heat stress reduces granulosa cell viability and proliferation in both in vivo and in vitro models. Oocyte maturation, both nuclear and cytoplasmic, is also compromised, and embryo quality declines under elevated thermal conditions. These effects are linked to intracellular disturbances, including oxidative imbalance, mitochondrial dysfunction, and altered hormonal signaling. The differences between in vivo and in vitro responses reflect the complexity of the biological impact of heat stress and emphasize the protective role of the physiological microenvironment. A better understanding of how heat stress alters the function of ovarian follicles, oocytes, and embryos is crucial. This knowledge is critical to devise effective strategies that mitigate damage, support fertility, and improve outcomes in assisted reproduction for livestock exposed to high environmental temperatures. Full article

The hypothalamus–pituitary–ovarian (HPO) axis orchestrates reproductive functions through intricate neuroendocrine crosstalk. Here, we integrated single-nucleus RNA sequencing (snRNA-seq) and spatial transcriptomics (ST) to decode the cellular heterogeneity and intercellular communication networks in the reproductive systems of pregnant Mongolian cattle. We retained a total of 6161 high-quality nuclei from the hypothalamus, 14,715 nuclei from the pituitary, and 26,072 nuclei from the ovary, providing a comprehensive cellular atlas across the HPO axis. In the hypothalamus, neurons exhibited synaptic and neuroendocrine specialization, with glutamatergic subtype Glut4 serving as a TGFβ signaling hub to regulate pituitary feedback, while GABAergic GABA1 dominated PRL signaling, likely adapting maternal behavior. Pituitary stem cells dynamically replenished endocrine populations via TGFβ, and lactotrophs formed a PRL–PRLR paracrine network with stem cells, synergizing mammary development. Ovarian luteal cells exhibited steroidogenic specialization and microenvironmental synergy: endothelial cells coregulated TGFβ-driven angiogenesis and immune tolerance, while luteal–stromal PRL–PRLR interactions amplified progesterone synthesis and nutrient support. Granulosa cells (GCs) displayed spatial-functional stratification, with steroidogenic GCs persisting across pseudotime as luteinization precursors, while atretic GCs underwent apoptosis. Spatial mapping revealed GCs’ annular follicular distribution, mediating oocyte–somatic crosstalk, and luteal–endothelial colocalization supporting vascularization. This study unveils pregnancy-specific HPO axis regulation, emphasizing multi-organ crosstalk through TGFβ/PRL pathways and stem cell-driven plasticity, offering insights into reproductive homeostasis and pathologies. Full article

Background: Against the backdrop of the large-scale and intensive development of the livestock industry, enhancing the reproductive efficiency of cattle has become a crucial factor in industrial development. Holstein cows, as the most predominant dairy cattle breed globally, are characterized by high milk yield and excellent milk quality. However, their reproductive efficiency is comprehensively influenced by a variety of complex factors, and improving their reproductive performance faces numerous challenges. The ovary, as the core organ of the female reproductive system, plays a decisive role in embryonic development and pregnancy maintenance. It is not only the site where eggs are produced and developed but it also regulates the cow’s estrous cycle, ovulation process, and the establishment and maintenance of pregnancy by secreting various hormones. The normal functioning of the ovary is crucial for the smooth development of the embryo and the successful maintenance of pregnancy. Methods: Currently, traditional sequencing technologies have obvious limitations in deciphering ovarian function and reproductive regulatory mechanisms. To overcome the bottlenecks of traditional sequencing technologies, this study selected Holstein cows as the research subjects. Ovarian samples were collected from one pregnant and one non-pregnant Holstein cow, and single-nucleus transcriptome sequencing technology was used to conduct an in-depth study on the ovarian cells of Holstein cows. Results: By constructing a cell type-specific molecular atlas of the ovaries, nine different cell types were successfully identified. This study compared the proportions of ovarian cell types under different physiological states and found that the proportion of endothelial cells decreased during pregnancy, while the proportions of granulosa cells and luteal cells increased significantly. In terms of functional enrichment analysis, oocytes during both pregnancy and non-pregnancy play roles in the “cell cycle” and “homologous recombination” pathways. However, non-pregnant oocytes are also involved in the “progesterone-mediated oocyte maturation” pathway. Luteal cells during pregnancy mainly function in the “cortisol synthesis and secretion” and “ovarian steroidogenesis” pathways; non-pregnant luteal cells are mainly enriched in pathway processes such as the “AMPK signaling pathway”, “pyrimidine metabolism”, and “nucleotide metabolism”. Cell communication analysis reveals that there are 51 signaling pathways involved in the pregnant ovary, with endothelial cells, granulosa cells, and luteal cells serving as the core communication hubs. In the non-pregnant ovary, there are 48 pathways, and the interaction between endothelial cells and stromal cells is the dominant mode. Conclusions: This study provides new insights into the regulatory mechanisms of reproductive efficiency in Holstein cows. The differences in the proportions of ovarian cell types, functional pathways, and cell communication patterns under different physiological states, especially the increase in the proportions of granulosa cells and luteal cells during pregnancy and the specificity of related functional pathways, indicate that these cells play a crucial role in the reproductive process of cows. These findings also highlight the importance of ovarian cells in pathways such as “cell cycle”, “homologous recombination”, and “progesterone-mediated oocyte maturation”, as well as the cell communication mechanisms in regulating ovarian function and reproductive performance. Full article

Bacterial communities within the female upper genital tract may influence the risk of ovarian cancer. In this retrospective cohort pilot study, we aim to detect different communities of bacteria between ovarian cancer and normal controls using topic modeling, a natural language processing tool. RNA was extracted and analyzed using the VITCOMIC2 pipeline. Topic modeling assessed differences in bacterial communities. Idatuning identified an optimal latent topic number and Latent Dirichlet Allocation (LDA) assessed topic differences between high-grade serous ovarian cancer (HGSOC) and controls. Results were validated using The Cancer Genome Atlas (TCGA) HGSOC dataset. A total of 801 unique taxa were identified, with 13 bacteria significantly differing between HGSOC and normal controls. LDA modeling revealed a latent topic associated with HGSOC samples, containing bacteria Escherichia/Shigella and Corynebacterineae. Pathway analysis using KEGG databases suggest differences in several biologic pathways including oocyte meiosis, aldosterone-regulated sodium reabsorption, gastric acid secretion, and long-term potentiation. These findings support the hypothesis that bacterial communities in the upper female genital tract may influence the development of HGSOC by altering the local environment, with potential functional implications between HGSOC and normal controls. However, further validation is required to confirms these associations and determine mechanistic relevance. 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: Artificial intelligence (AI) and machine learning (ML) have been reshaping maternal, fetal, neonatal, and reproductive healthcare by enhancing risk prediction, diagnostic accuracy, and operational efficiency across the perinatal continuum. However, no comprehensive synthesis has yet been published. Objective: To conduct a scoping review of reviews of AI/ML applications spanning reproductive, prenatal, postpartum, neonatal, and early child-development care. Methods: We searched PubMed, Embase, the Cochrane Library, Web of Science, and Scopus through April 2025. Two reviewers independently screened records, extracted data, and assessed methodological quality using AMSTAR 2 for systematic reviews, ROBIS for bias assessment, SANRA for narrative reviews, and JBI guidance for scoping reviews. Results: Thirty-nine reviews met our inclusion criteria. In preconception and fertility treatment, convolutional neural network-based platforms can identify viable embryos and key sperm parameters with over 90 percent accuracy, and machine-learning models can personalize follicle-stimulating hormone regimens to boost mature oocyte yield while reducing overall medication use. Digital sexual-health chatbots have enhanced patient education, pre-exposure prophylaxis adherence, and safer sexual behaviors, although data-privacy safeguards and bias mitigation remain priorities. During pregnancy, advanced deep-learning models can segment fetal anatomy on ultrasound images with more than 90 percent overlap compared to expert annotations and can detect anomalies with sensitivity exceeding 93 percent. Predictive biometric tools can estimate gestational age within one week with accuracy and fetal weight within approximately 190 g. In the postpartum period, AI-driven decision-support systems and conversational agents can facilitate early screening for depression and can guide follow-up care. Wearable sensors enable remote monitoring of maternal blood pressure and heart rate to support timely clinical intervention. Within neonatal care, the Heart Rate Observation (HeRO) system has reduced mortality among very low-birth-weight infants by roughly 20 percent, and additional AI models can predict neonatal sepsis, retinopathy of prematurity, and necrotizing enterocolitis with area-under-the-curve values above 0.80. From an operational standpoint, automated ultrasound workflows deliver biometric measurements at about 14 milliseconds per frame, and dynamic scheduling in IVF laboratories lowers staff workload and per-cycle costs. Home-monitoring platforms for pregnant women are associated with 7–11 percent reductions in maternal mortality and preeclampsia incidence. Despite these advances, most evidence derives from retrospective, single-center studies with limited external validation. Low-resource settings, especially in Sub-Saharan Africa, remain under-represented, and few AI solutions are fully embedded in electronic health records. Conclusions: AI holds transformative promise for perinatal care but will require prospective multicenter validation, equity-centered design, robust governance, transparent fairness audits, and seamless electronic health record integration to translate these innovations into routine practice and improve maternal and neonatal outcomes. Full article

Endometriosis significantly impacts fertility through complex mechanisms. These include chronic inflammation, oxidative stress, and anatomical distortion. These mechanisms impair oocyte quality, embryo development, and implantation. While in vivo challenges persist, in vitro fertilization (IVF) offers a controlled environment to overcome some barriers. A systematic review of evidence is presented for (1) endometriosis-associated oocyte dysfunction, (2) conflicting IVF outcomes, and (3) innovative strategies. Significant medical advancements have been made. However, gaps remain in personalized prognosis and targeted therapies. Emerging tools, specifically AI-driven embryo selection, single-cell omics, and immunomodulation, are promising for improving outcomes. Hence, a patient-centered approach, balancing science with personalized care, is essential to navigate endometriosis-related infertility. Full article

The corpus luteum (CL) is a transient gland that can directly influence follicular dynamics and oocyte quality. The objective of this study was to evaluate the influence of the absence or presence of a small (≤3 mm), medium (4–8 mm), or large (>8 mm) CL in slaughterhouse ovaries on in vitro embryo production. Cumulus–oocyte complexes (COCs) were collected from each group of ovaries and matured in TCM-199 medium, plus hormones and fetal bovine serum. Fertilization was performed with fresh semen from a Katahdin ram of known fertility. Embryo development was carried out in commercial sequential media for 72 and 96 h, until the blastocyst stage. The number of follicles (2–6 mm in diameter) and COCs were influenced by the presence of CL, which was higher (p < 0.05) in the Large CL group (5.51 ± 0.33 and 3.62 ± 0.27) compared to the Without CL group (4.54 ± 0.19 and 2.62 ± 0.14, respectively), with no difference between the CL sizes. Likewise, the diameter and area of the COCs were higher in the Small CL group of ovaries compared to the Without CL group. In the Large CL group of ovaries, 9% more morulae (p < 0.05) were obtained compared to the Without CL group; in the Medium CL group, 13% more blastocysts were obtained compared to the Without CL group. However, in the hatching capacity and diameter of blastocysts, no statistical difference was evident (p > 0.05). In conclusion, the presence and size of the CL in the ovaries of slaughtered sheep influence the productive efficiency of embryos in vitro under the conditions in which the present study was carried out. Full article

Background: Nitric oxide (NO) is an important modulator of ovarian physiology, which contributes to angiogenesis, steroidogenesis, and redox control. The stable metabolites nitrate (NO₃⁻) and nitrite (NO₂⁻) may indicate real-time follicular function during IVF. Methods: In this prospective study, we included 89 women who underwent controlled ovarian stimulation. The Griess test was used to measure NO₂-NO₃ concentrations in follicular fluid collected on the day of oocyte retrieval. Non-parametric and correlation tests were used to investigate the associations between oocyte yield, maturity (MII), fertilization (2PN), embryo development, and hormone levels. Results: Higher NO₂-NO₃ levels were substantially associated with increased total oocyte count, MII oocytes (p = 0.014), and 2PN embryos (p = 0.029). This suggests a strong relationship between NO bioavailability and oocyte competence. NO₂-NO₃ levels showed a positive correlation with estradiol (p < 0.001) and progesterone (p < 0.001), suggesting a possible function in granulosa cell steroidogenesis. Conclusions: Follicular NO metabolites are candidate functional indicators for oocyte quality evaluation and intrafollicular steroidogenic activity. Their predictive value may improve customized IVF treatment, especially in individuals with complicated ovarian phenotypes such as PCOS or decreased ovarian reserve. Full article