Dynamics and necessity of SIRT1 for maternal-zygotic transition.

Dynamic changes in maternal‒zygotic transition (MZT) require complex regulation of zygote formation, maternal transcript decay, embryonic genome activation (EGA), and cell cycle progression. Although these changes are well described, some key regulatory factors are still elusive. Sirtuin-1 (SIRT1), an NAD+-dependent histone deacetylase, is a versatile driver of MZT via its epigenetic and nonepigenetic substrates. This study focused on the dynamics of SIRT1 in early embryos and its contribution to MZT. A conditional SIRT1-deficient knockout mouse model was used, accompanied by porcine and human embryos. Embryos across mammalian species showed the prominent localization of SIRT1 in the nucleus throughout early embryonic development. Accordingly, SIRT1 interacts with histone H4 on lysine K16 (H4K16) in both mouse and human blastocysts. While maternal SIRT1 is dispensable for MZT, at least one allele of embryonic Sirt1 is required for early embryonic development around the time of EGA. This role of SIRT1 is surprisingly mediated via a transcription-independent mode of action.

Melatonin protects against defects induced by methoxychlor in porcine oocyte maturation.

Methoxychlor (MXC) is a widely used organochlorine pesticide primarily targeting pests. However, MXC has been found to negatively impact the reproductive system of both humans and animals, triggering oxidative stress and apoptosis. Melatonin (MLT), an endogenous hormone, possesses various benefits, including circadian rhythm regulation and anti-inflammatory and antioxidative stress effects. Moreover, MLT plays a crucial role in the development of animal germ cells and embryos. This study aimed to investigate the impact of MLT on porcine oocytes exposed to MXC. The experimental findings revealed that 200 µM MXC had detrimental effects on the maturation of porcine oocytes. However, the addition of 10-8 M MLT mitigated the toxic effects of MXC. MXC induced oxidative stress in porcine oocytes, leading to an increase in reactive oxygen species and impairing mitochondrial function. Consequently, oocyte quality was affected, resulting in elevated levels of early apoptosis and DNA damage, ultimately negatively impacting subsequent embryonic development. However, the addition of MLT showed the potential to ameliorate the damage caused by MXC. In conclusion, our results suggest that MLT exhibits a protective effect against MXC-induced damage to porcine oocyte maturation.

Live birth rate after oocyte donation in females diagnosed with turner syndrome: a systematic review and meta-analysis.

BACKGROUND: An enduring challenge for women diagnosed with Turner syndrome (TS) is infertility. Oocyte donation (OD) offers a chance of pregnancy for these patients. However, current data on pregnancy outcomes are inadequate. Hence, this systematic review aims to explore the clinical outcomes of OD in patients with TS. METHODS: A systematic search was conducted in PubMed, Web of Sciences, Scopus, and Embase for relevant papers from 1 January 1990 to 30 November 2023. Our primary research objective is to determine the live birth rate among women with TS who have undergone in vitro fertilization (IVF) using OD for fertility purposes. Specifically, we aim to calculate the pooled live birth rates per patient and per embryo transfer (ET) cycle. For secondary outcomes, we have analyzed the rates of clinical pregnancy achievement per ET cycle and the incidence of gestational hypertensive complications per clinical pregnancy. Prevalence meta-analyses were performed using STATA 18.0 by utilizing a random-effects model and calculating the pooled rates of each outcome using a 95% confidence interval (CI). RESULTS: A total of 14 studies encompassing 417 patients were systematically reviewed. Except for one prospective clinical trial and one prospective cohort study, all other 12 studies had a retrospective cohort design. Our meta-analysis has yielded a pooled live birth rate per patient of 40% (95% CI: 29-51%; 14 studies included) and a pooled live birth rate per ET cycle of 17% (95% CI: 13-20%; 13 studies included). Also, the pooled clinical pregnancy achievement rate per ET cycle was estimated at 31% (95% CI: 25-36%; 12 studies included). Moreover, the pooled rate of pregnancy-induced hypertensive disorders per clinical pregnancy was estimated at 12% (95% CI: 1-31%; 8 studies included). No publication bias was found across all analyses. CONCLUSIONS: This study demonstrated promising pregnancy outcomes for OD in patients with TS. Further studies are essential to address not only the preferred techniques, but also the psychological, ethical, and societal implications of these complex procedures for these vulnerable populations. TRIAL REGISTRATION: This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration code CRD42023494273.

Identification of a novel splicing variant of thyroid hormone receptor interaction protein 13 (TRIP13) in female infertility characterized by oocyte maturation arrest.

PURPOSE: As a cause of primary female infertility, oocyte maturation arrest (OMA) is characterized by failure to obtain mature oocytes due to abnormal meiosis. We aimed to identify pathogenic variants in two sisters with OMA phenotype from a non-consanguineous family. METHODS: Whole-exome sequencing and Sanger sequencing were conducted to identify and validate the disease-causing gene variant. Additionally, we performed a minigene assay, quantitative reverse transcription PCR, and Western blotting to assess the effects of the variant. RESULTS: We identified a novel homozygous splicing variant (c.1021-11T>C) in TRIP13, which followed a recessive inheritance pattern. Minigene assay showed that the variant could disrupt the integrity of TRIP13 mRNA, as evidenced by the production of an alternative transcript with intron10 intermediate retention of 79 bp. Compared to normal controls, the expression of TRIP13 mRNA and abundance of TRIP13 protein were also significantly decreased in Epstein-Barr virus-immortalized lymphoblastoid cells derived from affected individuals. CONCLUSION: Our findings confirm the contribution of genetic factors to OMA and expand the mutation spectrum of TRIP13 in female infertility.

Safety and effectiveness of controlled ovarian stimulation and oocyte retrieval during prepubertal and peripubertal period.

PURPOSE: Is it safe and effective to perform controlled ovarian stimulation (COS) and oocyte retrieval (OR) in prepubertal and peripubertal patients? METHODS: In this retrospective cohort study, data of 20 pre-/peripubertal patients who underwent COS and OR for the purpose of oocyte cryopreservation (OC) between 2008 and 2023 were reviewed. Following COS, all OR procedures were performed transabdominally using a vaginal ultrasound probe. Ovarian reserve was assessed by serum FSH, LH, estradiol, AMH, and antral follicle counts (AFC) in all subjects. All mature oocytes were vitrified. RESULTS: Mean age of the patients was 15.05 ± 1.87, mean AMH was 0.84 ± 0.8 ng/ml, mean FSH was 6.39 ± 3.95 IU/L, mean estradiol was 61.6 ± 51.9 pg/ml, mean LH was 4.69 ± 3.46 IU/L, and mean AFC was 5.5 ± 5.82. Among the patients, 12 had regular menstrual cycle, 5 had irregular menstrual cycle, whereas 3 patients still did not have their menarche yet. The indications for OC were as follows: primary ovarian insufficiency (n = 7), ovarian surgery for ovarian tumors (n = 5) or ovarian torsion (n = 1), mosaic Turner syndrome (n = 2), acute lymphoblastic leukemia (n = 1) anaplastic B-cell lymphoma (n = 1), Ewing's sarcoma (n = 1), Noonan syndrome (n = 1), and Thalassemia (n = 1). The mean number of oocytes retrieved, MII oocytes frozen, and maturation rate were 5.11 ± 5.0, 3.92 ± 4.48, and 75.1 ± 25.6%, respectively. Stepwise linear regression analysis demonstrated a positive correlation between AFC and number of total oocytes retrieved and number of MII oocytes. In the case diagnosed with Noonan syndrome, all 7 retrieved oocytes were MI and all frozen at MI phase. No patient had any complication related to COS or OR. CONCLUSION: Even though number of the enrolled subjects is limited and mean AMH is lower in our cohort, we demonstrated that performing COS and OR is safe in pre-/peripubertal patients. If required, transabdominal route can be performed in this age group for OR. AFC appears as a prognostic factor for stimulation outcome in this age group. Pediatric patients or young adolescents at risk for primary ovarian insufficiency should not be discouraged from utilizing OC.

Transcriptomic analysis of the spatiotemporal axis of oogenesis and fertilization in C. elegans.

Caenorhabditis elegans hermaphrodite presents a unique model to study the formation of oocytes. However, the size of the model animal and difficulties in retrieval of specific stages of the germline have obviated closer systematic studies of this process throughout the years. Here, we present a transcriptomic level analysis into the oogenesis of C. elegans hermaphrodites. We dissected a hermaphrodite gonad into seven sections corresponding to the mitotic distal region, the pachytene region, the diplotene region, the early diakinesis region and the 3 most proximal oocytes, and deeply sequenced the transcriptome of each of them along with that of the fertilized egg using a single-cell RNA-seq (scRNA-seq) protocol. We identified specific gene expression events as well as gene splicing events in finer detail along the gonad and provided novel insights into underlying mechanisms of the oogenesis process. Furthermore, through careful review of relevant research literature coupled with patterns observed in our analysis, we delineate transcripts that may serve functions in the interactions between the germline and cells of the somatic gonad. These results expand our knowledge of the transcriptomic space of the C. elegans germline and lay a foundation on which future studies of the germline can be based upon.

Melatonin facilitates oocyte growth in goats and mice through increased nutrient reserves and enhanced mitochondrial function.

Oogenesis involves two phases: initial volumetric growth driven by nutrient accumulation and subsequent nuclear maturation. While melatonin (MLT) has been employed as a supplement to enhance the quality of fully grown oocytes during nuclear maturation phase, its impact on oocyte growth remains poorly studied. Here, we provide in vivo evidence demonstrating that follicle-stimulating hormone increases MLT content in ovary. Administration of MLT improves oocyte growth and quality in mice and goats by enhancing nutrient reserves and mitochondrial function. Conversely, MLT-deficient mice have smaller oocytes and dysfunctional mitochondria. Exploring the clinical implications of MLT in promoting oocyte growth, we observe that a brief 2-day MLT treatment enhances oocyte quality and reproductive performance in older mice. These findings highlight the role of MLT in regulating oocyte growth and provide a specific treatment window for optimizing oocyte quality and reproductive performance in female animals.

Impact of Bisphenol A and its alternatives on oocyte health: a scoping review.

BACKGROUND: Bisphenol A (BPA) is an endocrine disrupting chemical released from plastic materials, including food packaging and dental sealants, persisting in the environment and ubiquitously contaminating ecosystems and human populations. BPA can elicit an array of damaging health effects and, alarmingly, 'BPA-free' alternatives mirror these harmful effects. Bisphenol exposure can negatively impact female fertility, damaging both the ovary and oocytes therein. Such damage can diminish reproductive capacity, pregnancy success, and offspring health. Despite global government regulations in place to indicate 'safe' BPA exposure levels, these policies have not considered the effects of bisphenols on oocyte health. OBJECTIVE AND RATIONALE: This scoping review was conducted to evaluate evidence on the effects of BPA and BPA alternatives on standardized parameters of oocyte health. In doing so, this review addresses a critical gap in the literature providing a comprehensive, up-to-date synthesis of the effects of bisphenols on oocyte health. SEARCH METHODS: This scoping review was conducted in accordance with PRISMA guidelines. Four databases, Medline, Embase, Scopus, and Web of Science, were searched twice (23 February 2022 and 1 August 2023) to capture studies assessing mammalian oocyte health post-bisphenol exposure. Search terms regarding oocytes, ovarian follicles, and bisphenols were utilized to identify relevant studies. Manuscripts written in English and reporting the effect of any bisphenol on mammalian oocyte health from all years were included. Parameters for toxicological studies were evaluated, including the number of bisphenol concentrations/doses tested, dosing regimen, biological replicates and/or animal numbers, and statistical information (for human studies). Standardized parameters of oocyte health including follicle counts, oocyte yield, oocyte meiotic capacity, morphology of oocyte and cumulus cells, and oocyte meiotic spindle integrity were extracted across the studies. OUTCOMES: After screening 3147 studies, 107 studies of either humans or mammalian animal models or humans were included. Of the in vitro exposure studies, 96.3% (26/27) and 94.1% (16/17) found at least one adverse effect on oocyte health using BPA or BPA alternatives (including BHPF, BPAF, BPB, BPF, and BPS), respectively. These included increased meiotic cell cycle arrest, altered morphology, and abnormal meiotic spindle/chromosomal alignment. In vivo, 85.7% (30/35) of studies on BPA and 92.3% (12/13) on BPA alternatives documented adverse effects on follicle development, morphology, or spindle/chromosome alignment. Importantly, these effects were recorded using levels below those deemed 'safe' for human exposure. Over half (11/21) of all human observational studies showed associations between higher urinary BPA levels and reduced antral follicle counts or oocyte yield in IVF patients. Recommendations are presented based on the identified shortcomings of the current evidence, incorporating elements of FDA requirements for future research in the field. WIDER IMPLICATIONS: These data highlight the detrimental impacts of low-level BPA and BPA alternative exposure, contributing to poor oocyte quality and reduced fertility. These outcomes are valuable in promoting the revision of current policies and guidelines pertaining to BPA exposure internationally. This study serves as a valuable resource to scientists, providing key recommendations on study design, reporting elements, and endpoint measures to strengthen future studies. Ultimately, this review highlights oocyte health as a fundamentally important endpoint in reproductive toxicological studies, indicating an important direction for future research into endocrine disrupting chemicals to improve fertility outcomes.

VPS34 Governs Oocyte Developmental Competence by Regulating Mito/Autophagy: A Novel Insight into the Significance of RAB7 Activity and Its Subcellular Location.

Asynchronous nuclear and cytoplasmic maturation in human oocytes is believed to cause morphological anomalies after controlled ovarian hyperstimulation. Vacuolar protein sorting 34 (VPS34) is renowned for its pivotal role in regulating autophagy and endocytic trafficking. To investigate its impact on oocyte development, oocyte-specific knockout mice (ZcKO) are generated, and these mice are completely found infertile, with embryonic development halted at 2- to 4-cell stage. This infertility is related with a disruption on autophagic/mitophagic flux in ZcKO oocytes, leading to subsequent failure of zygotic genome activation (ZGA) in derived 2-cell embryos. The findings further elucidated the regulation of VPS34 on the activity and subcellular translocation of RAS-related GTP-binding protein 7 (RAB7), which is critical not only for the maturation of late endosomes and lysosomes, but also for initiating mitophagy via retrograde trafficking. VPS34 binds directly with RAB7 and facilitates its activity conversion through TBC1 domain family member 5 (TBC1D5). Consistent with the cytoplasmic vacuolation observed in ZcKO oocytes, defects in multiple vesicle trafficking systems are also identified in vacuolated human oocytes. Furthermore, activating VPS34 with corynoxin B (CB) treatment improved oocyte quality in aged mice. Hence, VPS34 activation may represent a novel approach to enhance oocyte quality in human artificial reproduction.

Maturational competence of equine oocytes is associated with alterations in their "cumulome".

Assisted reproductive technologies are an emerging field in equine reproduction, with species dependent peculiarities, such as the low success rate of conventional in vitro fertilisation. Here, the "cumulome" was related to the developmental capacity of its corresponding oocyte. Cumulus oocyte complexes (COCs) collected from slaughterhouse ovaries were individually matured, fertilised by intracytoplasmic sperm injection (ICSI), and cultured. After maturation, the cumulus was collected for proteomics analysis using label-free mass spectrometry (MS) based protein profiling by nano-HPLC MS/MS and metabolomics analysis by UPLC-nanoESI MS. Overall, a total of 1671 proteins and 612 metabolites were included in the quantifiable "cumulome". According to the development of the corresponding oocytes, three groups were compared with each other: not matured (NM; n = 18), cleaved (CV; n = 15) and blastocyst (BL; n = 19) groups. CV and BL were also analysed together as the matured group (M; n = 34). The dataset revealed a closer connection within the two M groups and a more distinct separation from the NM group. Over-representation analysis detected enrichments related to energy metabolism as well as vesicular transport in the M group. Functional enrichment analysis found only the KEGG pathway of oxidative phosphorylation as significantly enriched in NM group. A compound attributed to ATP was observed with significantly higher concentrations in the BL group compared with the NM group. Finally, in the NM group, proteins related to degradation of glycosaminoglycans were lower and components of cumulus extracellular matrix were higher compared to the other groups. In summary, the study revealed novel pathways associated with the maturational and developmental competence of oocytes.

Informed consent and coercion in recruitment advertisements for oocyte donors.

BACKGROUND: As the use of donor eggs for in vitro treatment has increased, both medically affiliated and private donor egg agencies have turned to online advertisements to recruit donors. The American Society for Reproductive Medicine provides recommendations encouraging ethical recruitment of donors, however there is no formal regulation for the informed consent process for egg donor recruitment and compensation. Underrepresentation of risks and targeted financial incentives may pose a risk to the informed consent process. METHODS: Data from online advertisements for egg donors active between January 1 - August 31, 2020, were collected to analyze content related to risks, Covid-19 precautions, donor payment, and desired donor characteristics. Advertisements for egg donors on Google, Craigslist, and social media were analyzed. Primary outcomes included the mention of the risks of egg donation, including the risk of Covid-19 exposure, in donor egg advertisements. Secondary outcomes included language targeting specific donor characteristics and financial compensation. RESULTS: 103 advertisements were included. 35.9% (37/103) of advertisements mentioned some risk of the egg donation process, and 18.5% (19/103) mentioned risks or precautions related to Covid-19 exposure. Of advertisements for private donor egg agencies, 40.7% (24/59) mentioned any risk, compared to 29.6% (13/44) of medically affiliated egg donation programs; the difference was not statistically significant (p-value = 0.24). Agencies targeting students and donors of a specific race were more likely to offer payments over $10,000 for an egg donation cycle. Among advertisements offering over $20,000 for donor compensation, 72.7% (8/11) recruited women under the age of 21. CONCLUSION: Egg donor recruitment advertisements, for both medically affiliated programs and private agencies, were unlikely to mention risks including the risk of exposure to Covid-19. Non-medically affiliated private donor egg agencies were more likely to violate multiple American Society for Reproductive Medicine ethics guidelines, including offering higher than average compensation, and recruiting donors from young and vulnerable populations.

Fertility preserving techniques in neuro-oncology patients: A systematic review.

Background: Advancements in cancer treatments have enhanced survival rates and quality of life for patients with central nervous system (CNS) tumors. There is growing recognition of the significance of fertility preservation methods. Currently, techniques, including oocyte cryopreservation and sperm cryopreservation are established. Nevertheless, oncologists may exhibit reluctance when referring patients to reproductive specialists. This review aimed to assess the best evidence for fertility preservation techniques used in patients with CNS cancers and evaluate outcomes relating to their success and complications. Methods: Two reviewers performed a search of Pubmed, Embase, Medline, Cochrane, and Google Scholar. Papers were included if they reported at least 1 fertility preservation technique in a neuro-oncology patient. Non-English studies, editorials, animal studies, and guidelines were excluded. Meta-analysis was performed using the random effects model. Results: Sixteen studies containing data from 237 participants (78.8% female) were included in the systematic review and meta-analysis, of whom 110 (46.4%) underwent fertility preservation techniques. All patients (100%) successfully underwent fertility preservation with 1 participant (2.9%) returning to rewarm their oocytes, embryos or sperm. On average, 17.8 oocytes were retrieved with 78%, ultimately being cryopreserved. Five (6.0%) patients successfully conceived 9 healthy-term children after utilizing their cryopreserved sperm, embryos, or oocytes. Moreover, 6 patients successfully conceived naturally or using intrauterine insemination, resulting in 7 healthy-term children. Conclusions: Fertility preservation techniques could offer a safe and effective way for neuro-oncology patients to deliver healthy-term babies following treatment. However, further studies concerning risks, long-term pregnancy outcomes, and cost-effectiveness are needed.

Calcium signaling in oocyte quality and functionality and its application.

Calcium (Ca2+) is a second messenger for many signal pathways, and changes in intracellular Ca2+ concentration ([Ca2+]i) are an important signaling mechanism in the oocyte maturation, activation, fertilization, function regulation of granulosa and cumulus cells and offspring development. Ca2+ oscillations occur during oocyte maturation and fertilization, which are maintained by Ca2+ stores and extracellular Ca2+ ([Ca2+]e). Abnormalities in Ca2+ signaling can affect the release of the first polar body, the first meiotic division, and chromosome and spindle morphology. Well-studied aspects of Ca2+ signaling in the oocyte are oocyte activation and fertilization. Oocyte activation, driven by sperm-specific phospholipase PLCζ, is initiated by concerted intracellular patterns of Ca2+ release, termed Ca2+ oscillations. Ca2+ oscillations persist for a long time during fertilization and are coordinately engaged by a variety of Ca2+ channels, pumps, regulatory proteins and their partners. Calcium signaling also regulates granulosa and cumulus cells' function, which further affects oocyte maturation and fertilization outcome. Clinically, there are several physical and chemical options for treating fertilization failure through oocyte activation. Additionally, various exogenous compounds or drugs can cause ovarian dysfunction and female infertility by inducing abnormal Ca2+ signaling or Ca2+ dyshomeostasis in oocytes and granulosa cells. Therefore, the reproductive health risks caused by adverse stresses should arouse our attention. This review will systematically summarize the latest research progress on the aforementioned aspects and propose further research directions on calcium signaling in female reproduction.

Development of an AI-based support system for controlled ovarian stimulation.

Purpose: Controlled ovarian stimulation (COS) is vital for IVF. We have developed an AI system to support the implementation of COS protocols in our clinical group. Methods: We developed two models as AI algorithms of the AI system. One was the oocyte retrieval decision model, to determine the timing of oocyte retrieval, and the other was the prescription inference model, to provide a prescription similar to that of an expert physician. Data was obtained from IVF treatment records from the In Vitro Fertilization (IVF) management system at the Asada Ladies Clinic, and these models were trained with this data. Results: The oocyte retrieval decision model achieved superior sensitivity and specificity with 0.964 area under the curve (AUC). The prescription inference model achieved an AUC value of 0.948. Four models, namely the hCG prediction model, the hMG prediction model, the Cetrorelix prediction model, and the Estradiol prediction model included in the prescription inference model, achieved AUC values of 0.914, 0.937, 0.966, and 0.976, respectively. Conclusion: The AI algorithm achieved high accuracy and was confirmed to be useful. The AI system has now been implemented as a COS tool in our clinical group for self-funded treatments.

True empty follicle syndrome is a subtype of oocyte maturation abnormalities.

Objective: To review the outcomes of in vitro maturation (IVM) and in vitro fertilization (IVF) in women with empty follicle syndrome (EFS). The study evaluated the genetic underpinnings of EFS by analyzing mutations. Materials and Methods: This retrospective case series involving 17 women with EFS over at least 2 IVF cycles was conducted. The study also employed whole-exome sequencing to analyze the genetic mutations. The treatment approaches included letrozole-primed IVM, follicle-stimulating hormone (FSH)-human chorionic gonadotrophin (hCG)-primed IVM, and conventional IVF. Results: The average female age was 31.5±4.6 years, and the duration of infertility was 7.3±3.5 years. Four patients underwent IVF. IVM oocyte collections yielded oocytes in 12 of 13 subjects. Of these, 75% (9/12) yielded MII oocytes after 48 h of IVM media incubation. Six subjects had fertilized embryos, resulting in a 40.9% intracytoplasmic sperm injection (ICSI) fertilization rate (9 embryos/22 MII oocytes). Genetic analysis revealed mutations in seven patients. This study demonstrated the partial efficacy of letrozole-primed IVM plus growth hormone and FSH-hCG primed IVM protocols. No pregnancies or live births were recorded after IVM. One ongoing pregnancy post-IVF and one spontaneous live birth were observed. Conclusion: Inter-cycle variabilities were observed in women with oocyte maturation abnormalities (OMAs). Almost all patients with EFS had oocytes collected during IVM following IVF. These oocytes have limited potential for maturation, fertilization, and live birth, as demonstrated by the low rates observed after IVM culture and ICSI. These conditions are observed in OMAs due to defects in the oocyte machinery. The proposed flowchart provides a comprehensive classification approach for various forms of EFS.

Transcriptomic analysis of meiotic genes during the mitosis-to-meiosis transition in Drosophila females.

Germline cells produce gametes, which are specialized cells essential for sexual reproduction. Germline cells first amplify through several rounds of mitosis before switching to the meiotic program, which requires specific sets of proteins for DNA recombination, chromosome pairing, and segregation. Surprisingly, we previously found that some proteins of the synaptonemal complex, a prophase I meiotic structure, are already expressed and required in the mitotic region of Drosophila females. Here, to assess if additional meiotic genes were expressed earlier than expected, we isolated mitotic and meiotic cell populations to compare their RNA content. Our transcriptomic analysis reveals that all known meiosis I genes are already expressed in the mitotic region; however, only some of them are translated. As a case study, we focused on mei-W68, the Drosophila homolog of Spo11, to assess its expression at both the mRNA and protein levels and used different mutant alleles to assay for a premeiotic function. We could not detect any functional role for Mei-W68 during homologous chromosome pairing in dividing germ cells. Our study paves the way for further functional analysis of meiotic genes expressed in the mitotic region.

Angiotensin II type-1 receptor autoantibody positively correlates with the rate of metaphase I oocytes in infertility with ovulatory disorder.

The renin-angiotensin system (RAS) plays an important role in reproductive function. Our previous study identified that angiotensin II type-1 receptor autoantibody (AT1-AA), an autoantibody that activates RAS, was closely associated with infertility. However, its distribution in different types of infertility remained unclear. This study was designed to explore the distribution of AT1-AA in infertile patients and the connections between AT1-AA and oocyte development and pregnancy outcome. A total of 184 infertile women participated, with samples collected from peripheral venous blood. ELISA was used to detect AT1-AA levels in their sera. It was observed that the proportion of ovulation-disorder factors in AT1-AA-positive group was significantly higher than that in negative group (P=0.001). In 59 infertile women with ovulatory disorders, compared with negative group, AT1-AA-positive group had lower rate of retrieval (P=0.032) and metaphase II (MII) oocytes (P=0.011) but higher proportion of metaphase I (MI) oocytes (P=0.019). A negative correlation was found between the levels of AT1-AA and rate of retrieval and MII oocytes (P=0.027; P=0.043), whereas a positive correlation was observed with the proportion of MI oocytes (P=0.002). Moreover, a specific predictive value for proportion of reaching MII and MI oocytes was exhibited by AT1-AA (P < 0.01; P < 0.05). But no significant difference in embryonic parameters or pregnancy outcomes between two groups was observed (P > 0.05). This study revealed that serum AT1-AA levels were significantly increased in infertile women with ovulatory disorders and positively correlated with proportion of MI oocytes, but not associated with outcomes of assisted reproduction.

The global phosphorylation landscape of mouse oocytes during meiotic maturation.

Phosphorylation is a key post-translational modification regulating protein function and biological outcomes. However, the phosphorylation dynamics orchestrating mammalian oocyte development remains poorly understood. In the present study, we apply high-resolution mass spectrometry-based phosphoproteomics to obtain the first global in vivo quantification of mouse oocyte phosphorylation. Of more than 8000 phosphosites, 75% significantly oscillate and 64% exhibit marked upregulation during meiotic maturation, indicative of the dominant regulatory role. Moreover, we identify numerous novel phosphosites on oocyte proteins and a few highly conserved phosphosites in oocytes from different species. Through functional perturbations, we demonstrate that phosphorylation status of specific sites participates in modulating critical events including metabolism, translation, and RNA processing during meiosis. Finally, we combine inhibitor screening and enzyme-substrate network prediction to discover previously unexplored kinases and phosphatases that are essential for oocyte maturation. In sum, our data define landscape of the oocyte phosphoproteome, enabling in-depth mechanistic insights into developmental control of germ cells.

Does insulin-like growth factor-I level associate with pregnancy outcomes in primary and secondary infertile women undergoing in vitro fertilization? A prospective cohort study.

BACKGROUND: Infertility, which affects 8%-12% of couples worldwide and 21.9% of couples in Pakistan in particular, is a major reproductive health issue. In vitro fertilization (IVF) has emerged as a prevalent therapeutic intervention. Recent studies have identified insulin-like growth factor-I (IGF-I) as a promising biomarker for assessing embryo viability and predicting implantation outcomes in IVF procedures.

In vitro exposure to butylparaben impairs the integrity and size of ovarian follicles in a bovine model.

There is a growing regulatory and scientific interest in the studies of environmental substances that are capable of interfering with the reproductive system. Among them, parabens stand out due to their widespread use and frequent detection as contaminants in human tissues and biological fluids. Therefore, we evaluated the toxic effects of butylparaben on the viability and follicular staging of bovine ovarian follicles in vitro. Fragments of ovaries from five cyclic bovine females were cultured for 44 h in a minimal essential medium (MEM; control) or MEM supplemented with 50 µg/mL and 100 µg/mL of butylparaben (BP 50 and BP 100 groups, respectively). The ovarian fragments were subjected to follicular staging, morphological analysis, morphometric analysis, estradiol analysis and oxidative profiling. No significant changes were observed between the experimental groups in follicular staging, estradiol analysis and oxidative profile analysis. However, the BP 50 group showed a significant decrease in the number of intact ovarian follicles. Moreover, a decrease in the follicular and oocyte diameters was observed in the groups that were exposed to butylparaben. In conclusion, butylparaben impairs the integrity and size of ovarian follicles in an in vitro bovine model, but does not affect the oxidative profile and steroidogenesis.