Search Results (391)

Background/Objectives: Oocyte maturation is a process involving both nuclear and cytoplasmic development regulated by epigenetic changes in gene expression. Cyclin-B3 (CCNB3) and cyclin-A2 (CCNA2) genes are thought to be involved in oocyte maturation; however, the expression profiles and key function in Metaphase-I (MI) and Metaphase-II (MII) phases have yet to be fully elucidated. Small non-coding RNA sequences are involved in epigenetic regulation of specific transcriptional targets, whereas microRNAs (miRNAs) participate in the post-transcriptional and translational repression of target genes. This study examined the expression levels of CCNB3, CCNA2, and their associated miRNAs (miR-17, miR-106b, miR-190a, miR-1275) in cumulus oophorous complex (COC) cells derived from MI and MII oocytes of NOR and DOR IVF cases, with particular emphasis on elucidating their functions during the transition from MI to MII stage. Methods: Follicular fluid containing cumulus–oocyte complex (COC) cells obtained from oocytes of 120 cases in each group NOR MI (n = 30), NOR MII (n = 30), DOR MI (n = 30), and DOR MII (n = 30) who were admitted to the Istanbul Bahçeci Health Group Assisted Reproductive Treatment Center. Following total RNA isolation from COC cells, the gene and protein expression levels of CCNB3 and CCNA2, along with the expression of miR-17, miR-106b, miR-190a, and miR-1275, were assessed using (qPCR-based assay) and immunohistochemistry (IHC). To investigate the functional roles of COC cell populations, morphological analysis was performed using H&E staining. Additionally, metadata of the cases, including age, number of oocytes, fertilization, and embryonic development rates, were evaluated. Results: The expressions of miR-17 and miR-1275 were significantly elevated in both NOR MI and DOR MI groups compared to their respective NOR MII and DOR MII groups (p < 0.05). Additionally, miR-106b levels were higher in the NOR MII group relative to NOR MI (p < 0.05), while an increase was also observed in DOR MI compared to DOR MII (p < 0.05). No difference was observed in miR-190a expression between the NOR and DOR (p > 0.05). Based on the results of H and E staining, the NOR MI, NOR MII, DOR MI, and DOR MII groups exhibited distinct variations in cellular morphology, nuclear characteristics, cytoplasmic volume, and cell density. Conclusions: CCNB3 is predicted to be a potential candidate for determining MI between the NOR and DOR cases. On the other hand, only for the NOR MII cases could CCNA2 provide evidence of oocyte maturation. Moreover, we determined the relationship between related genes and miRNAs which target CCNA2 and CCNB3. Genetic and protein expression analysis across diverse molecular pathways and miRNAs yielded comprehensive preliminary data regarding the developmental stages of oocytes at the MI and MII phases, and their fertilization potential following maturation shows potential and warrants prospective validation with clinical performance evaluation. Full article

The kodkod (Leopardus guigna) is a vulnerable wild felid native to South America whose population is steadily declining. ARTs offer valuable tools for the preservation of its genetic diversity. Our study provides the first evaluation of the morphological and functional acquisition of competence in kodkod oocytes using protocols previously established for domestic cat oocytes. In total, 29 iCOCs were obtained from the ovaries of a single juvenile female kodkod that deceased in a wildlife rehabilitation center. Based on morphological criteria, 13 oocytes were selected for IVM and subsequently evaluated for developmental competence following parthenogenetic activation (PA) and in vitro culture (IVC). Kodkod oocytes appear to be smaller and have a thinner zona pellucida compared to those of domestic cat oocytes. These kodkod oocytes demonstrated the ability to mature in vitro, underwent cleavage, and developed in vitro to the blastocyst stage by day 9. Here, we show that protocols to manage domestic cat oocytes and embryos can support kodkod in vitro oocyte maturation, activation, and in vitro embryo development. However, given that the results were obtained from a single individual and the protocols were tested in a limited number of oocytes, further studies involving additional specimens are essential to validate these observations and refine ART applications for kodkod conservation. Full article

Three populations of the western tubenose goby were analysed during the reproductive season of 2024 in the area of Žitný Island, Slovakia. Specimens were processed in the laboratory, where meristic and reproductive parameters were detected. Populations were female-dominated and all in good condition. Males showed a decrease in condition, probably due to different roles during reproduction. Females were characterised by increased values of the absolute (114–3997; mean 1299 oocytes) and relative number of oocytes (114–3206; mean 1225 oocytes), gonadosomatic index (3.02–93.27%; mean 19.49), and oocyte size (0.10–1.93 mm) compared to other native and/or invasive areas of occurrence. Comparing populations from 2024 with 2015, we found that females from the present study have smaller body sizes, higher values of absolute and relative number of oocytes, but lower values of gonadosomatic index and larger sizes of oocytes. This would suggest a shift to a more generalistic strategy based on a hypothesis derived from the theory of alternative ontogenies and invasive potential. Although the western tubenose goby is regarded as a native species in Slovakia, its reproductive parameters suggest a shift to more opportunistic behaviour. This pattern is consistent with its invasiveness in other non-native regions, such as parts of Europe and the Laurentian Great Lakes. Full article

Managing women with diminished ovarian reserve for in vitro fertilization (IVF) is challenging, often resulting in low oocyte yield and cycle failures. We hypothesize that coupling in vitro fertilization (IVF) with rescue in vitro maturation (r-IVM) can improve overall maturation rates without compromising the overall IVF outcome. Our study compared DOR and normal ovarian reserve (NOR) cohorts by evaluating 15 immature oocyte progressions following r-IVM. We analyzed the gene expression of cumulus cells related to GREM1, PTGS2, and HAS2 to correlate with OQ, EQ, and overall IVF outcome. Significant differences were noted in AMH levels, AFCs, and oocyte numbers (p < 0.05). Following r-IVM, the DOR cohort achieved a 50% maturation rate with improved overall quality; however, the difference was not statistically significant (p > 0.05). Fertilization rates were comparable, but EQ was better in DOR. All genes in DOR were upregulated post-r-IVM, whereas NOR showed downregulation of PTGS2 and GREM1 (p < 0.05). Otherwise, DOR exhibited higher pregnancy rates and live birth rates, although the difference was not statistically significant (p > 0.05). Overall, our findings suggest that r-IVM could provide improved fertility outcomes for DOR women in standard IVF cycles. Full article

Many experimental and clinical studies published so far demonstrate that melatonin—produced mainly by the pineal gland located deep in the middle of the brain, between the two cerebral hemispheres, and in smaller quantities in a number of other organs and cells of the body—can be successfully used to treat different types of human female infertility. To accomplish this, melatonin acts mainly on the ovary, the uterus, and the preimplantation embryo, through its antioxidant, anti-inflammatory, and immunomodulatory effects, in addition to acting as a hormone and cytokine modulator. In particular, it increases oocyte developmental competence and uterine receptivity for the implanting embryo, improves placental health and function, prevents immune rejection of the implanting embryo and spontaneous pregnancy loss, and alleviates symptoms of endometriosis and adenomyosis. Yet, the use of melatonin in these contexts remains relatively limited, despite its convincing safety profile. This may be partly due to the fact that pertinent data concerning the use of melatonin in female infertility treatment are dispersed across various specialized scientific and medical journals, making it difficult for doctors and embryologists confronted with female infertility issues to access all of them. Therefore, this article was written to provide data that are easily understood. It draws from recent findings collected from different specialized journals focused on the molecular mechanisms of action, the clinical data, and the safety of this multifaceted biomolecule in the treatment of female infertility. Full article

This study investigated the effects of high (atmospheric) and low (5% O₂) oxygen tension, as well as a combination of the two, on oocyte metabolism and quality during maturation. Cumulus cell–oocyte complexes collected from gilt ovaries were used for in vitro maturation. In addition, RNA-seq was conducted on the cumulus cells. Low oxygen tension throughout oocyte maturation did not alter the developmental rate to the blastocyst stage; however, it increased oocyte ATP and lipid content while reducing mitochondrial reactive oxygen species and mitochondrial membrane potential. Low-oxygen conditions increased glucose consumption but reduced mitochondrial DNA copy number and mitochondrial protein in cumulus cells. RNA-seq of cumulus cells revealed that low oxygen tension reduced mitochondrial activity and increased glycolysis, with the upregulation of glycolytic genes and downregulation of oxidative phosphorylation and steroidogenesis-related genes. In addition, a two-step oxygen protocol with low (5%) for the first period (0–21 h) and high (20%) for the last half period (21–44 h) increased the ATP and lipid content in oocytes and improved the embryonic developmental ability of the oocytes compared to the high-oxygen group. In conclusion, low oxygen tension during the first part of the maturation period is beneficial for oocyte quality, considering the observed metabolic changes. Full article

Background: Demand for elective oocyte cryopreservation (OC) among healthy women delaying childbearing is rising worldwide. Yet, clinicians and patients often rely on limited or indirect evidence to predict age-specific mature oocyte yield. Robust, real-world benchmarks are needed to guide expectations, estimate live birth potential, and optimize treatment planning. Methods: We retrospectively analyzed 400 healthy women aged 30–41 undergoing their first elective OC cycle between 2019 and 2023 at a large, university-affiliated fertility center. Exclusion criteria included infertility, polycystic ovary syndrome, prior ovarian surgery, and other medical indications for OC. All cycles used a standardized GnRH antagonist protocol with an initial gonadotropin dose of 300 IU/day. Only mature (metaphase II) oocytes were cryopreserved. Age-specific percentiles for total and mature oocyte yield were modeled using the General Additive Model for Location, Scale, and Shape (GAMLSS), and nomograms were developed. Results: Mean age was 35.7 years (SD 2.3). Median total and mature oocytes retrieved were 13 (IQR 9–19) and 10 (IQR 7–15), respectively. At the 50th percentile, women aged 30, 35, and 40 yielded 20, 14, and 9 total oocytes, with 15, 11, and 6 mature oocytes cryopreserved. Nomograms across percentiles illustrated a consistent, progressive decline in yield with advancing age. Conclusions: Age-based nomograms derived from real-world data can offer a clinically relevant tool to estimate the likely oocyte yield per cycle. They can help set realistic expectations, guide the number of cycles needed to meet fertility goals, and support evidence-based, shared decision-making in elective OC. Full article

Objectives: This retrospective single-center cohort study aims to evaluate the impact of dual-trigger therapy (recombinant hCG [rhCG] combined with GnRH agonist) compared to rhCG alone on ART outcomes in women undergoing GnRH antagonist protocols. Methods: Data from 1291 IVF cycles performed between 2016 and 2022 were analyzed. After propensity score matching (PSM) to adjust for confounders, 395 cycles in each group were compared. Primary outcomes included the total number of oocytes retrieved, while secondary outcomes assessed mature oocytes, fertilization rates, and embryo numbers. Results: Dual-trigger therapy yielded significantly more total oocytes (7.50 ± 5.23 vs. 6.12 ± 4.23, p < 0.001) and mature oocytes (5.67 ± 3.87 vs. 5.01 ± 3.13, p = 0.047) compared to rhCG alone. Cycles with no oocytes were fewer in the dual-trigger group (1.3% vs. 3.8%, p = 0.015). Total embryos were also higher with dual trigger therapy (2.43 ± 1.90 vs. 2.00 ± 1.93, p = 0.001). In intracytoplasmic sperm injection (ICSI) cycles, the fertilization rate significantly improved with dual trigger (64.93 ± 33.50% vs. 52.22 ± 34.12%, p = 0.003). No significant differences were noted in fertilization rates for standard IVF (55.14 ± 30.72% vs. 52.29 ± 32.11%, p = 0.18) or maturation rates (72.52 ± 26.91% vs. 71.53 ± 24.75%, p = 0.37). Conclusions: These findings demonstrate that dual-trigger therapy improves ART outcomes by increasing oocyte and embryo yields. Full article

The brown planthopper, Nilaparvata lugens, a major rice pest, harbors yeast-like symbionts (YLSs) that form mutualistic relationships with the host, significantly influencing its development and reproduction. As proteasome subunits play major roles in the assembly and functional maintenance of the proteasome, but their regulation on the YLSs in N. lugens are unclear. In this study, we analyzed the spatiotemporal and temporal expression patterns of five N. lugens proteasome subunits (NlPSMA2, NlPSMB5, NlPSMC4, NlPSMD10, NlPSMD13), and further verified their functions on the transovarial transmission of YLSs, in addition to the reproduction of N. lugens, based on RNA interference (RNAi). The results showed that NlPSMA2, NlPSMB5, NlPSMC4, NlPSMD10, and NlPSMD13 were highly expressed in ovarian follicular cells of N. lugens upon sexual maturation. After suppressing the expression of these genes by RNAi, N. lugens exhibited a shortened lifespan, abnormal pear-shaped follicles, and impaired oviposition capacity, but the number of YLSs in the whole body and the oocyte of N. lugens were significantly increased. These results indicate that the proteasome subunits play crucial roles in the reproduction of N. lugens and the transovarial transmission of its YLSs. Full article

The number of female astronauts participating in space missions is increasing, and concerns about the impact of spaceflight on reproductive health have emerged. Space radiation and microgravity pose potential threats to ovarian reserve and uterine function, but data on human female reproductive health in space remain scarce. This review explores current evidence from both real and simulated space conditions, including animal studies and ground-based cosmic radiation models. The relevant literature on cosmic radiation, fertility preservation strategies, and gynecological risk management in spaceflight was analyzed to provide a comprehensive synthesis. Space radiation might damage ovarian follicles and impair folliculogenesis, potentially leading to premature ovarian failure and microgravity might alter endocrine function. While human data are lacking, murine and in vitro model studies suggest significant reproductive risks. Embryo/oocyte and ovarian tissue cryopreservation are currently the most viable fertility preservation strategies. Shielding technologies, radioprotective agents, and hormonal modulation may offer adjunct protection. In conclusions, fertility counseling and preservation should become integral to pre-mission planning for female astronauts of reproductive age. A personalized approach, accounting for individual reproductive goals, age and mission duration, is essential. Further research is urgently needed to understand the reproductive effects of deep space travel and to develop targeted protective strategies. Full article

Background/Objectives: The success of artificial reproductive technologies (ARTs) depends on different factors, such as patient-specific reproductive features, ovarian response to stimulation, oocyte and embryo quality, and endometrial receptivity. This study aimed to evaluate their association with oocyte yield, fertilization, endometrial thickness, and pregnancy outcomes. Methods: A prospective clinical study included 128 women undergoing IVF/ICSI. Baseline hormone levels (E2, P4, FSH, LH, AMH) were assessed prior to stimulation. E2 levels were monitored during stimulation, and P4 was measured on the day of oocyte retrieval. Patients were grouped based on P4 levels (<2 ng/mL vs. ≥2 ng/mL). IVF outcomes and endometrial characteristics were statistically analyzed. Results: Lower P4 levels (<2 ng/mL) on the day of oocyte retrieval were significantly associated with higher fertilization rates (p < 0.003), more fertilized oocytes (p < 0.001), and increased pregnancy rates (p < 0.001). Elevated P4 (≥2 ng/mL) correlated with a higher frequency of thin endometrium (<7 mm, p < 0.007). E2 levels on the hCG trigger day correlated positively with the number of retrieved and mature oocytes and fertilization outcomes (p < 0.05). Patients who achieved pregnancy had lower P4 and BMI, and higher E2, AMH, and endometrial thickness. ROC identified a P4 threshold of 1.99 ng/mL with moderate predictive value. Conclusions: Elevated progesterone levels on the day of oocyte retrieval negatively impact fertilization and pregnancy outcomes, likely due to impaired endometrial receptivity. Combined assessment of P4, E2, AMH, and endometrial thickness may enhance embryo transfer planning and improve IVF success rates. Full article

Transvaginal ultrasound-guided follicle aspiration remains the gold standard for oocyte retrieval in assisted reproductive technology (ART). This procedure employs either a single-lumen aspiration needle (SLN) or double-lumen aspiration needle (DLN), both of which are effective modalities for oocyte retrieval. The primary objective of this review is to systematically compare the impact and clinical outcomes associated with the use of SLN versus DLN in women undergoing ART. A systematic literature search was conducted across two databases, PubMed and Google Scholar, encompassing publications from their inception until May 2025, and articles published in English. A total of five studies were included in the final analysis. The oocyte yield and the number of MII oocyte did not differ significantly between the groups. Procedural duration was markedly shorter in the SLN group compared to the DLN group. No significant differences were observed in procedure-related complications across groups. Two randomized controlled trials reported comparable fertilization rates and numbers of high-quality embryos between the two needle types. Additionally, clinical pregnancy rates, ongoing pregnancy rates, and live birth rates were similar between the SLN and DLN groups. In conclusion, the utilization ofan SLN for oocyte retrieval demonstrates comparable efficacy to that of a DLN. 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

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

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