Understanding the reproductive patterns and strategies of a species is an important step in establishing the species’ life history. Campostoma oligolepis, the Largescale Stoneroller, is a species that has received little attention in the 90 years since it was first identified, and the work that has been done has been localized in the American Midwest. Collections of C. oligolepis were made monthly from the Flint River in Madison County in northern Alabama, USA, from March, 2014, to September, 2015. A total of 768 fish were collected over the collection period including 492 adults, 268 females and 224 males. We found strong evidence that the peak spawning time for C. oligolepis in the Flint River is March and April. Ovarian maturation, gonadosomatic index for both sexes, and monthly clutch size all support this conclusion. Two unexpected features were found. The first is how few females of mature size were found to carry either oocytes or a clutch except in the peak observed reproductive month of April, 2014. The second unusual feature is the prevalence of asymmetric ovaries, with the left the larger if a difference exists. Campostoma oligolepis may have unusually strong inter-annual responses to abiotic factors such as water temperature and river discharge.

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possible due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore playing a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed, and at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.

The signal transducer and activator of transcription 3 (Stat3) is activated in response to the phosphorylation of Y705 (pStat3) and has the dual function of signal transduction and activation of transcription. Our previous study suggested that pStat3 is functional during oocyte maturation when transcription is silenced. Therefore, we speculated that pStat3 may have another function. Immunocytochemical analysis revealed that pStat3 emerges at the microtubule asters and spindle and then localizes at the spindle poles concomitant with a Pericentrin during mouse oocyte maturation. When we examined conditionally knocked out Stat3−/− oocytes, we detected Stat3 and pStat3 proteins. The localization of the pStat3 was the same as that of Stat3+/+ oocytes, and the oocyte maturation proceeded normally, suggesting that pStat3 was still functioning. The oocytes were treated either with the Stat3 specific inhibitors, Stattic and BP-1-102, or anti-pStat3 antibody injection. This caused significant abnormal spindle assembly and chromosome mis-location in a dose-dependent manner, in which the pStat3 was either negative or localized improperly. Moreover, development of pre-implantation stage embryos derived from inhibitor-treated oocytes was also hampered significantly after in vitro fertilization. These findings indicate a novel function of pStat3 involved in spindle assembly.

This paper provides an overview of the social reasons that lead women to consider egg cryopreservation, as well as the attitudes and knowledge of women towards this procedure. Methods: For the creation of this article, a literature review was carried out both in the existing medical literature and in search engines. The key points are 1. The main reasons women choose to delay childbearing are the lack of a suitable male partner, education and career advancement, and financial instability. Women feel societal and family pressure to have children, even though they may not feel ready. 2. Women's attitudes towards egg cryopreservation vary. While some are open to the idea, many are opposed to it, especially when it is used for non-medical reasons. There are concerns about the success rates, health risks, and ethical implications of the procedure. 3. The legal and regulatory framework around egg cryopreservation differs across countries. Some countries allow it only for medical reasons, while others have more permissive policies. The issue of who should bear the financial cost of the procedure is also debated. 4. There is a need to better educate women, as well as healthcare providers, about fertility decline and the options available for preserving fertility, including egg cryopreservation.

Abstract: To obtain bovine oocytes in high quality, effects of vitamin C (VC) on in vitro maturation (IVM) of bovine oocytes and early embryo development were investigated. The results showed that: 1) The IVM medium containing 50 µg/mL VC improved the oocyte maturation rate, while no effects on the development of parthenogenetic embryos; 2) The in vitro culture (IVC) medium containing 20 µg/mL VC increased the cleavage rate of the in vitro fertilized (IVF) embryos, enhanced the mRNA levels of pluripotency gene Oct4, Sox2, Cdx2 and Nanog in the blastocysts, but no effect on the blastocyst rate; 3) Combing supplemention of 50 µg/mL in IVM medium + 20 µg/ml VC in IVC medium (VC 50/20) increased the cleavage rate of IVF embryos and enhanced the mRNA levels of Oct4, Sox2, Cdx2 and Nanog in the blastocysts; 4) Combination of VC 0/20 and VC 50/20 enhanced the expression of anti-apoptotic gene Bcl-2 and VC 50/0 weakened the expression of pro-apoptotic gene Bax, while VC 0/40 and VC 0/60 increased Bax expression and decreased the Bcl-2/Bax ratio in blastocysts. Together, VC supplementation at tuned concentration as well its combination in IVM and IVC media improves the developmental rates of bovine oocytes and embryos.

In vitro fertilization (IVF) has revolutionized the field of assisted reproductive technologies (ART) by offering hope to individuals and couples struggling with infertility. Nevertheless, traditional IVF methods are not exempt from drawbacks, such as suboptimal success rates, intrusive procedures, and ethical considerations. The introduction of micro/nanorobotics in IVF offers a revolutionary chance to tackle these difficulties. This paper presents a short review of the utilization of micro/nanorobotics in IVF, investigating progress in the manipulation of sperm, retrieval of oocytes, culture of embryos, and potential future developments in this fast progressing area. In this discussion, we explore the fundamental concepts, advantages, difficulties, and possible influence of micro/nanorobotics in transforming IVF processes and enhancing patient outcomes.

Is there any possible synergic effect of fertility outcome between spindle view-assisted intracyto-plasmic sperm injection (SV-ICSI) with or without assisted oocyte activation (AOA) for patients with low fertilization rate history? To explore the answer, a retrospective study was held in our fertility center by reviewing patients receiving SV-ICSI during 2019/03 to 2023/06. Total 47 pa-tients were included, the fertility outcomes of intervention group (AOA-SV-ICSI, 14 patients) and control group (SV-ICSI, 33 patients), such as fertilization rate, blastocyst formation rate and clin-ical pregnancy rate, were analyzed. The blastocyst formation rate between groups was signifi-cantly higher in AOA-SV-ICSI group (p=0.020), but the fertilization rate and clinical pregnancy rate did not reach any statistical significance. This discovery of increased blastocyst formation rate in low fertilization rate patients could possibly help them in getting more usable embryos in fertility treatment.

The elevated environment temperature in summer plays adverse effects on bovine fertility. Antioxidant treatment may have positive impact to enhance oocyte competence could be possible strategy for alleviating the summer effects on bovine fertility. The present study was aimed to investigate the effects of exogenous melatonin treatment on oocyte development competence, blastocyst development rate, activity of antioxidant enzymes, expression profiles of development related genes and pregnancy rates in cattle during summer. The experiment was conducted in 44 non-lactating indigenous Sahiwal cattle divided into control and treatment group. Treatment group received (day 0) inj. Melatonin @ 18mg/50kg body weight while control group received inj. Corn oil, 4ml i.m. On day 4, all the cows were subjected to ovum pickup (OPU) to aspirate oocytes for in-vitro embryo production. Blood samples were used to determine lipid peroxidation (MDA) and antioxidant enzymes concentration (SOD, GSH), and also for plasma hormonal concentration analysis. The results revealed that blastocyst development rate (%) was higher in treatment group (p<0.05). Treatment group had increased (p<0.05) antioxidant enzymes (SOD and GSH), plasma melatonin and estradiol concentrations, and decreased (p<0.05) MDA concentrations than controls. The mRNA expression level of SOD2, HSPB1, BCL2, MT2 and STAR in oocytes, cumulus cells, COCs (immature and mature) and blastocyst were found to be higher, however, BAX was downregulated in melatonin-treated than control group. In conclusion, the results suggesting probable beneficial role of exogenous melatonin administration in reducing heat stress and enhancing blastocyst developmental competence in indigenous cattle.

Rates of involuntary childness are on the uprise which can bring high medical costs and emotional afflictions. This review explores the emerging roles of CoQ10 - including the ubiquinol form in fertility. PubMed, Science Direct and Google Scholar were searched for RCTs, retrospective or prospective controlled studies published between January 1, 2009, and April 31, 2024. The keywords CoQ10, ubiquinol, fer/sub/infertility, ovarian reserve, oocyte quality, ovulation, amenorrhea, polycystic ovary syndrome, sperm quality, seminal fluid, and IVF were used. A total of 15 publications were identified. From a mechanistic stance CoQ10 appears to improve mitochondrial energetics, attenuate oxidative stress and modifications to DNA, proteins, and lipids. Such mechanisms appear to underpin improvements in oocyte quality/fertilization, markers of sperm quality and more broadly PCOS symptoms and hormone levels which can impact on fertility. The role of the ubiquinol form looks particularly promising, which may be attributed to its bioavailability. Ongoing research is needed but there is scope to raise CoQ10 awareness amongst reproductive health experts.

Post-ovulatory aging (POA) is an inevitable factor during some assisted reproduction technology procedures, and results in poor fertilization rates and impaired embryo development. This study used RNA sequencing analysis and experimental validation to study the similarities and differences between in vivo- and in vitro-matured porcine oocytes before and after POA. Differentially expressed genes (DEGs) between fresh in vivo-matured oocyte (F_vivo) and aged in vivo-matured oocyte(A_vivo) and DEGs between fresh in vitro-matured oocyte (F_vitro) and aged in vitro-matured oocyte(A_vitro) were intersected to explore the co-effects of POA. It was found that "organelles", especially "mitochondria", were significantly enriched GO terms. The expression of genes related to the “electron transport chain” and “cell redox homeostasis” pathways related to mitochondrial function significantly showed low expression patterns in both A_vivo and A_vitro groups. WGCNA analysis to explore gene expression modules specific to A_vivo. Trait-modules association analysis showed that the red modules were most associated with in vivo aging. There are a total of 959 genes in the red module, which are mainly enriched in “RNA binding”, “mRNA metabolic process”, etc. GO terms, and “spliceosome” and “nucleotide excision repair” pathways. DNAJC7, IK, and DDX18 were at the hub of the gene regulatory network. And these genes were all expressed higher in A_vivo. In summary, POA affects the organelle function of oocytes. A_vivo oocytes have some unique gene expression patterns. These genes may be potential anti-aging targets. This study helps us understand the detailed mechanism of POA and provides strategies for researching oocyte aging.

In the field of human in vitro fertilization (IVF), selecting the best oocyte for freezing or embryo for transfer remains an important focus of clinical practice. Although several techniques are and have been used for this goal, results have generally not been favorable and/or are invasive such that damage to some embryos occurs, resulting in a reduced number of healthy births. Therefore, the search continues for non-invasive oocyte and embryo quality markers that signal the development of high-quality embryos. Multiple studies indicate the important positive effects of retinoic acid (RA) on oocyte maturation and function. Here, we present evidence that part of these effects are via the ability of RA to regulate the activity of connexin 43 (Cx43), the main subunit of gap junction channels in human cumulus granulosa cells (CGC). These channels play an important role in regulating the micronutrient environment of the oocyte by allowing the transfer of ions, metabolites, and small molecules. Multiple studies have demonstrated the requirement for Cx43 in CGC for the normal progression of folliculogenesis, and that increased expression of this connexin is linked to improved developmental competence of the oocyte. The data has shown that RA can up-regulate gap junction intercellular communication (GJIC) in the cumulus-oocyte complex by a non-genomic mechanism that results in the dephosphorylation of Cx43 and enhanced GJIC. Recognizing the positive role played by gap junctions in CGC on oocyte development and the regulation of Cx43 by RA, the findings have highlighted the possibility that CGC RA levels may serve as a non-invasive indicator for selecting high-quality oocytes for IVF procedures. In addition, the data suggests that manipulation of Cx43 with retinoid compounds could provide new pharmacological approaches to improve IVF outcomes in cases of failed implantation, recurrent miscarriage, or in certain diseases that are characterized by reduced fecundity, such as endometriosis.

It is known that exposure to heavy metals such as lead (Pb) and cadmium (Cd) has several adverse effects, particularly on the human reproductive system. Pb and Cd have been associated with infertility in both men and women. In pregnant women, they have been associated with spontaneous abortion, preterm birth, and impairment of the development of the fetus. Since these heavy metals come from both natural and anthropogenic activities and their harmful effects have been observed even at levels of exposure, their exposure remains a public health issue, especially for the reproductive system. Given this, the present study aimed to investigate the potential reproductive effects of Pb and Cd levels in the follicular fluid (FF) of infertile women and no-smokers exposed to heavy metals for professional reasons or living in rural areas near landfills and waste disposal areas, to correlate the intrafollicular presence of these metals with possible alterations in the ultrastructure of human cumulus-oocyte complexes (COCs), probably responsible of infertility. Blood and FF metals were measured using atomic absorption spectrometry. COCs corresponding to each FF analyzed were subjected to ultrastructural analyses by transmission electron microscopy. We demonstrated for the first time that intrafollicular levels of Pb (0.66 µg/dL to 0.85 µg/dL) and Cd (0.26 µg/L - 0.41 µg/L) could be associated with morphological alterations of both the oocyte and CCs ultrastructure. Since blood Cd levels (0.54 µg/L - 1.87 µg/L) were above the current reference values established by the guidelines of the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA), whereas blood Pb levels (1.28 µg/dL - 3.98 µg/dL) were below the ATSDR reference values we believe that these alterations could be due especially to Cd, even if we cannot exclude a possible additional effect of Pb. Our results highlighted that oocytes were affected in maturation and quality, whereas CCs showed scarcely active steroidogenic elements. Regressing CCs, with cytoplasmic alterations, were also numerous. According to Cd's endocrine-disrupting activity, the poor steroidogenic activity of CCs might correlate with delayed oocyte cytoplasmic maturation. So, we conclude that levels of heavy metals in the blood and the FF might negatively affect fertilization, embryo development, and pregnancy, compromising oocyte competence to fertilization both directly and indirectly, impairing CC steroidogenic activity, and inducing CC apoptosis.

In our recent report, we clarified the direct interaction between excitatory amino acid transporter (EAAT) 1/2 and polyunsaturated fatty acids (PUFAs) by applying electrophysiological and molecular biological techniques to Xenopus oocytes. Xenopus oocytes have a long history of use in the scientific field, but they are still attractive experimental systems for neuropharmacological studies. We will therefore summarize the pharmacological significance, advantages, (especially in the study of EAAT2), and experimental techniques that can be applied to Xenopus oocytes; our new findings concerning L-glutamate (L-Glu) transporters and PUFAs; and the significant outcomes of our data. The data obtained from electrophysiological and molecular biological studies of Xenopus oocytes have provided us with further important questions, such as whether or not some PUFAs can modulate EAATs as allosteric modulators and to what extent docosahexaenoic acid (DHA) affects neurotransmission and thereby affects brain functions. By combining Xenopus oocyte experiments and more translational approaches, we can clarify the functions of proteins that are difficult to examine using cultured cells and the physiological roles of these proteins in brain functions. These approaches can lead to the development of the new central nervous system (CNS) drugs targeting molecules and investigations of their effectiveness.

Current commercially available instruments for monitoring mitochondrial respiration are incapable of single cell measurements. Therefore, we developed a three-electrode, Clark-type biosensor suitable for mitochondrial respirometry in single oocytes and embryos. The biosensor was embedded in a PMMA (polymethyl methacrylate) micro-chamber to allow investigation of single oocytes/embryos immersed in up to 100 µL of respiration buffer. The micro-chamber was completely sealed to avoid oxygen exchange between the inside of the chamber and the atmosphere, while being maintained at a temperature of 38.5 ˚C to preserve cell viability. Using amperometry, the oxygen consumption of cells inside the micro-chamber was measured as a change in output current and converted to femto-mol (fmol) oxygen consumed per second based on calibrations with known buffer oxygen concentrations. The sensor measured basal cell respiration supported by endogenous substrates, respiration associated with proton leak induced by inhibition of the adenosine triphosphate (ATP) synthase (complex V) with oligomycin, and the maximal non-coupled respiratory capacity revealed by Carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) titration. Some potential applications of this oxygen sensor system include evaluating effects of metabolic therapies on oocyte bioenergetics, and monitoring mitochondrial function throughout oocyte maturation and blastocyst development to predict embryo viability to compliment assisted reproductive technologies

During fertilization, the fusion of the spermatozoa with the oocytes causes the release of calcium from the oocyte endoplasmatic reticulum. This, in turn, triggers a series of calcium ion (Ca2+) oscillations, a process known as oocyte activation. The sperm-specific factor responsible for oocyte activation is phospholipase C zeta (PLCζ). Men undergoing intracytoplasmic sperm injection (ICSI) with their spermatozoa lacking PLCζ are incapable of generating Ca2+oscillation, leading to fertilization failure. The immunofluorescence assay is the most used technique to assess the expression and localization of PLCζ and to diagnose patients with reduced/absent ability to activate the oocytes. In these patients, the use of assisted oocyte activation (AOA) technique can help to yield successful ICSI results and shorten the time of pregnancy. However, the production of a stable PLCζ recombinant protein represents a new powerful therapeutic approach to treating individuals with this condition. We aim to conduct a systematic review focusing on the expression, level, and localization of PLCζ, discussing the novel genetic mutation associated with its impairment. In addition, we highlight the benefits of AOA, looking at new and less invasive methods to diagnose and treat cases with PLCζ dysfunction ability.

International guidelines are published in oncology to provide standardized information and fertility preservation (FP) care for adults and children with cancer. For benign gynecologic diseases (BGD), many recommendations are based on data coming from oncofertility studies rather than studies with a stronger and broader evidence base. The purpose of the study was to conduct a modified Delphi process for generating FP guidelines for BGD. A steering committee identified 42 potential FP practices for BGD. Then 114 key stakeholders were asked to participate in a modified Delphi process via two online survey rounds and a final meeting. Consensus was reached for 28 items. Among them, stakeholders rated age-specific information concerning the risk of diminished ovarian reserve after surgery as important but rejected proposals setting various upper and lower age limits for FP. All women should be informed about the benefit/risk balance of oocyte vitrification, in particular about the likelihood of live birth according to age. FP should not be offered in rASRM stages I and II endometriosis without endometriomas. These guidelines could be useful for gynecologists to identify situations at risk of infertility and to better inform women with BGDs who might need personalized counseling for FP.

In mammals, the oviduct (or the Fallopian tube in humans) can be divided into the infundibulum (responsible for oocyte pick-up), ampulla (site of fertilization), isthmus (where preimplantation embryos develop), and uterotubal junction (where embryos transit to the uterus). The oviductal fluid, as well as extracellular vesicles produced from the oviductal epithelial cells, referred to as oEVs, have been shown to improve the fertilization process, prevent polyspermy, and aid in embryo development. oEVs contain molecular cargos (such as miRNAs, mRNAs, proteins, and lipids) that can be delivered and fuse to recipient cells. oEVs produced from the ampulla appear to be functionally distinct from those produced from the isthmus. In multiple species including mice, cats, dogs, pigs, and cows, oEVs can be incorporated into the oocytes, sperm, and embryos. In this review, we show the positive impact of oEVs on gamete function as well as blastocyst development and how they may improve embryo quality in in vitro conditions in an assisted reproductive technology setting for rodents, domestic animals, farm animals, and humans.

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30 to 40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of non-invasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different non-invasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated to better competence. In addition, the combination of oocyte and zygote selection by BCB test and spindle imaging have the potential to further optimize the identification of oocytes with better developmental competence for in vitro-derived technologies in livestock species.

Ovariectomy appears to be the best method to control the density of wild ungulate populations. The aim of the present study was to compare two surgical approaches, via the flank and midline, in mouflon’s ovariectomy in field conditions. Twenty female mouflons were enrolled in the study. The animals were divided randomly in two groups, Group F animals were gonadectomized via flank approach, while Group A animals were sterilized via linea alba access. The parameters evaluated were duration of surgery, duration of anaesthesia, recovery time, intra- and post-operative complications, intra-operative nociception and pain in the post-operative period. There were no intra- and post-operative complications. The evaluated parameters showed a very similar trend in both groups. Both techniques are found to be effective and safe in execution.

Environmental and occupational exposure to hexavalent chromium, Cr(VI), causes female reproductive failures and infertility. Cr(VI) is used in more than 50 industries and is a group-A carcinogen, mutagenic and teratogenic, and a male and female reproductive toxicant. Our previous findings indicate that Cr(VI) causes follicular atresia, trophoblast cell apoptosis, and mitochondrial dysfunction in metaphase II (MII) oocytes. However, the integrated molecular mechanism of Cr(VI)-induced oocyte defects are not understood. The current study investigates the mechanism of Cr(VI) in causing meiotic disruption of MII oocytes, leading to infertility in superovulated rats. Postnatal day (PND)-22 rats were treated with potassium dichromate (1 and 5 ppm) in drinking water from PND 22-29 and superovulated. MII oocytes were analyzed by immunofluorescence, and images were captured by confocal microscopy and quantified by Image Pro Plus software. Our data showed that Cr(VI) increased microtubule misalignment, missegregation of chromosomes, a bulged and folded actin cap, oxidative DNA and protein damage, increased DNA double-strand break, and DNA repair protein RAD51. Cr(VI) also induced incomplete cytokinesis and delayed polar body extrusion. Our study indicates that exposure to environmentally relevant doses of Cr(VI) caused severe DNA damage, distorted oocyte cytoskeletal proteins, and caused oxidative DNA and protein damage leading to infertility.

Resveratrol is one of the most investigated natural polyphenolic compounds and is contained in more than 70 types of plants and in red wine. The widespread interest in this polyphenol derives from its antioxidant, anti-inflammatory and anti-aging properties. Several studies have established that resveratrol regulates animal reproduction. However, the mechanisms of action and the potential therapeutic effects are still unclear. This review aims to clarify the role of resveratrol in the male and female reproductive functions, with a focus on animals of veterinary interest. In the female, resveratrol has been considered a phytoestrogen due to its capacity to modulate ovarian function and steroidogenesis via sirtuins, SIRT1, in particular. Resveratrol has also been used to enhance aged oocyte quality, and as a gametes cryo-protectant with mainly antioxidant, and anti-apoptotic effects. In the male, resveratrol enhanced testes function and spermatogenesis through activation of AMPK pathway. Furthermore, resveratrol has been supplemented to semen extenders improving the preservation of sperm quality. In conclusion, resveratrol has potentially beneficial effects for ameliorating ovarian and testes function. However, due to unclear data, further studies are necessary to consolidate these findings.