• Analysis of the mechanism(s) of metaphase I-arrest in strain LT mouse oocytes: delay in the acquisition of competence to undergo the metaphase I/anaphase transition. (jax.org)
  • Given the lack of correlation, we conclude that proteome analysis of mouse oocytes may not be surrogated with transcriptome analysis. (gotomydoctor.com)
  • We analysed maternal ageing of mouse oocytes on the protein level, using SILAC technology and high- However, searching these studies for culprits resolution MS, to define its signature at a level closer elicits a list of candidate genes that is quite short, to phenotype than mRNA. (gotomydoctor.com)
  • It was found that FIGNL1, a member of MTSPs, was predominantly expressed in mouse oocytes and distributed at the spindle poles during meiosis in the present study. (cambridge.org)
  • In affected ovaries, oxygenation of follicular fluid is low, ultrastructural disturbances especially of mitochondria, occur in granulosa cells and oocytes, and considerable disturbances of meiosis occur. (biomedcentral.com)
  • cGMP (during follicular growth) can prevent untimely oocyte meiotic resumption up to ovulation (after LH surge, after increase in LH). (kiev.ua)
  • The follicular fluid (FF) provides a crucial microenvironment for the proper development of follicles and oocytes through tightly controlled metabolism and cell signaling. (biomedcentral.com)
  • Growth of the dominant follicle encompasses enlargement of the oocyte, replication of follicular cells, and formation and expansion of a fluid-filled follicular antrum or cavity, providing a specialized microenvironment for the development of oocytes. (biomedcentral.com)
  • observed that heat stress during the follicular recruit- the regulating mechanism of oocyte maturation. (sagepub.com)
  • CiErk1/2 also induced expression of matrix metalloproteinase (CiMMP2/9/13) in the oocyte, resulting in collagen degradation in the outer follicular cell layer and liberation of fertile oocytes from the ovary. (elifesciences.org)
  • factor(s) relies on gene transcription that oocytes largely Oocytes spend most of their time quiescent in primordial perform during follicular growth prior to ovulation, and follicles, mature over days or weeks during follicular the transcriptional activities of oocytes may be influ- growth and then become quiescent again near the enced by maternal age. (gotomydoctor.com)
  • In vitro maturation (IVM) is the technique of letting the contents of ovarian follicles and the oocytes inside mature in vitro. (wikipedia.org)
  • In 1935, Pincus & Enzmann did the first experiment on immature rabbit oocyte, showing in vitro spontaneous maturation and fertilization. (wikipedia.org)
  • The best oocytes are chosen to be matured in the hope of then being implanted using in vitro fertilisation techniques. (wikipedia.org)
  • Levels of reactive oxygen species (ROS) and SIRT1 were higher in in vitro-matured oocytes derived from aged cows than in those derived from their younger counterparts. (elsevierpure.com)
  • This study was conducted to evaluate in vivo and in vitro development of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection. (bioone.org)
  • Oocytes were collected from slaughterhouse-derived ovaries, matured in vitro, and injected with frozen-thawed stallion sperm. (bioone.org)
  • Being able to reproduce those conditions in vitro could lead to successful oocyte maturation and positive fertilization outcomes. (juniperpublishers.com)
  • Whether the maturation happens in vivo or in vitro, the environment to which the oocyte and its surrounding cells are exposed, affects the developmental competence of the oocyte and subsequent embryonic development [ 5 ]. (juniperpublishers.com)
  • In both cases, being able to reproduce the conditions in vitro by recreating the follicle microenvironment using cultured granulosa cells may be necessary for successful oocyte maturation, either before or after freezing. (juniperpublishers.com)
  • Poor ovarian responders (POR) are women undergoing in-vitro fertilization who respond poorly to ovarian stimulation, resulting in the retrieval of lower number of oocytes, and subsequently lower pregnancy rates. (biomedcentral.com)
  • In the current study, we investigated the beneficial effects of resveratrol on in vitro porcine oocyte maturation under heat stress (HS). (sagepub.com)
  • The disruption of the levels of steroid hormones Animal Genetics and Breeding of the Ministry of Agriculture, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and caused the mature failure of in vitro cultured oocytes. (sagepub.com)
  • In this study, we first examined the ovulation of Ciona intestinalis Type A by monitoring follicle rupture in vitro, identifying a novel mechanism of neuropeptidergic regulation of oocyte maturation and ovulation. (elifesciences.org)
  • Practically, cycle regulation, chromosome stability and epigenetic F9 cells allow for the efficient metabolic labelling of the modification, in both mouse and human oocytes SILAC reference in vitro, overcoming the difficulty of directly labelling oocytes in vivo. (gotomydoctor.com)
  • FF-MAS increases the quality of in vitro oocyte maturation, and thus the developmental potential of oocytes exposed to FF-MAS during in vitro maturation is improved. (cambridge.org)
  • Germinal vesicle breakdown (GVBD) occurs during oocyte meiotic maturation, a period when transcriptional processes are virtually inactive. (biomedcentral.com)
  • To characterize the effect of artificially increasing MIR21 on oocyte competence without inhibiting GVBD, a MIR21 mimic, scrambled microRNA negative control, or nuclease free water was micro-injected into denuded oocytes at 21 h of IVM. (biomedcentral.com)
  • Following germinal vesicle break down (GVBD) the oocyte is transcriptionally quiescent until fertilization and activation of the embryonic genome, occurring at the four-cell stage of development in the pig [ 9 ]. (biomedcentral.com)
  • The germinal vesicle breakdown (GVBD) is a landmark event of oocyte maturation. (cambridge.org)
  • In our previous studies, we found that zona pellucida 3 (ZP3) was strongly concentrated in the nuclear region of germinal vesicle (GV) oocytes and interacted with aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) and lamin A to promote GVBD. (cambridge.org)
  • The presence of cumulus cells improves developmental competence of GV oocytes in control groups but it did not affect the vitrified group. (ijfs.ir)
  • Zavareh, S., Salehnia, M., Saberivand, A. Comparison of Different Vitrification Procedures on Developmental Competence of Mouse Germinal Vesicle Oocytes in the Presence or Absence of Cumulus Cells. (ijfs.ir)
  • Oocytes are classified depending on their condition, such as number of cumulus cells. (wikipedia.org)
  • Maturation of the mammalian oocyte is a complex process involving internal checkpoints and bidirectional communication with the surrounding cumulus cells. (biomedcentral.com)
  • We focus primarily on the role of both types of granulosa cells: mural granulosa cells, which perform endocrine functions, including hormone production and cumulus cells, which provide metabolic support and establish bi-directional communication with the oocyte through various pathways, including direct contact. (juniperpublishers.com)
  • During ovulation, the primary oocyte will resume meiosis in response to signals, arresting in metaphase meiosis II, ready for fertilization. (wikipedia.org)
  • These protease-induced decreases in IGFBP-4 and -5 likely cause increased levels of bioavailable (or free) IGFs that stimulate steroidogenesis and mitogenesis in developing dominant follicles, which ultimately prepare the follicle(s) and oocyte(s) for successful ovulation and fertilization. (bioone.org)
  • Ascidians are the closest living relatives of vertebrates, and their study is important for understanding the evolutionary processes of oocyte maturation and ovulation. (elifesciences.org)
  • This is the first demonstration of essential pathways regulating oocyte maturation and ovulation in ascidians and will facilitate investigations of the evolutionary process of peptidergic regulation of oocyte maturation and ovulation throughout the phylum Chordata. (elifesciences.org)
  • Therefore, the regulatory mechanisms underlying oocyte maturation and ovulation control not only the reproduction of the respective organisms but also evolutionary processes across the animal kingdom. (elifesciences.org)
  • Some neuropeptides have been shown to induce oocyte maturation and ovulation (or spawning) in several species of invertebrates. (elifesciences.org)
  • These findings demonstrate that various neuropeptides are responsible for triggering oocyte maturation and ovulation in invertebrates, and suggest that oocyte maturation and ovulation and their underlying molecular mechanisms are regulated in both a species-specific and evolutionarily conserved fashion. (elifesciences.org)
  • Independently of the gestational periods, the qualitative evaluation showed the initial wash-in phase from the first appearance of the uterine artery to the rapid distribution in embryonic vesicles or placenta to the progressive washout, whilst there was no enhancement of either embryos or fetuses in any bitch. (edu.au)
  • In general, maternal age affects the quality of oocytes and embryos. (elsevierpure.com)
  • The present study aimed to examine the features and age-associated gene expression profiles of bovine oocytes and embryos as well as to discover possible countermeasures against age-associated events. (elsevierpure.com)
  • Comprehensive gene expression assays of germinal vesicle and metaphase II (MII)-stage oocytes and 8- to 16-cell-stage embryos were conducted using next-generation sequencing technology. (elsevierpure.com)
  • Another drawback of oocyte vitrification is diminished developmental potential because of the decreased quality of embryos after warming. (molcells.org)
  • As a result of a lower number of oocytes retrieved, there are fewer embryos to select and transfer, and subsequently these patients have lower pregnancy rates per transfer and lower cumulative pregnancy rates per started cycle compared with normal responders. (biomedcentral.com)
  • The effect of resveratrol, melatonin and their combination on alleviating HS was compared according to the maturation rate of oocytes and the development competence of embryos after parthenogenetic activation (PA). (sagepub.com)
  • Results: Supplementation with resveratrol (2.0 μmol/L) not only improved the nuclear maturation but also raised the blastocyst rate of porcine embryos' PA from oocytes that underwent HS by increasing their glutathione (GSH) level, reducing reactive oxygen species (ROS) and up-regulating the expression of Sirtuin 1 (SIRT1). (sagepub.com)
  • Finally, we show that establishment of non-CpG methylation, which is prevalent in fully grown oocytes, and methylation over non-transcribed regions, are later events in oogenesis. (biomedcentral.com)
  • Fully grown oocytes of most laboratory mice progress without interruption from the germinal vesicle (GV) stage to metaphase II, where meiosis is arrested until fertilization. (jax.org)
  • It has been suggested that immature oocytes may be more resistant to cryodamage due to lower cell volume and lack of metaphase spindle. (juniperpublishers.com)
  • In contrast, many oocytes of strain LT mice arrest precociously at metaphase I and often undergo subsequent spontaneous parthenogenetic activation. (jax.org)
  • Cytostatic factor (CSF), which prevents the degradation of cyclin B and maintains high maturation-promoting factor (MPF) activity, is required for maintenance of metaphase I-arrest in LT oocytes, similar to its requirement for maintaining metaphase II-arrest in normal oocytes. (jax.org)
  • However, CSF does not instigate metaphase I-arrest since a temporary metaphase I-arrest occurs in MOS-null LT oocytes. (jax.org)
  • However, it was found that LT oocytes do not acquire competence to undergo the metaphase I/anaphase transition in response to 6-DMAP until 50-60 min after normal oocytes. (jax.org)
  • A similar delay was observed in strain CX8-4 oocytes, which also have a high incidence of metaphase I-arrest, but not in strain CX8-11 oocytes, which exhibit a low incidence of metaphase I-arrest. (jax.org)
  • MOS-null LT oocytes also exhibit a delay in acquisition of competence to undergo the metaphase I/anaphase transition. (jax.org)
  • Thus, a delay in competence to undergo the metaphase I/anaphase transition in response to 6-DMAP-treatment correlates with metaphase I-arrest. (jax.org)
  • It is therefore hypothesized that the observed delay in acquisition of competence to enter anaphase I may instigate the sustained metaphase I-arrest in LT oocytes by allowing CSF activity to rise to a level that prevents cyclin B degradation and maintains high MPF activity before anaphase can be initiated by normal triggering mechanisms. (jax.org)
  • Mature oocytes become fertilizable, and their meiosis is arrested again at a species-specific stage: metaphase of the first division (MetI, many invertebrates), metaphase of the second division (MetII, most vertebrates), or G1-phase (some echinoderms and coelenterates) until fertilization. (elifesciences.org)
  • Of these primordial follicles, only around 400 mature oocytes are released and could be potentially fertilised, with the rest undergoing atresia. (wikipedia.org)
  • Primordial follicles containing the primary oocyte, arrested at prophase of meiosis I, develop into primary follicle containing cuboidal granulosa cells. (wikipedia.org)
  • If without the use of priming, oocytes are obtained when the largest follicles are around 10mm in size. (wikipedia.org)
  • Oocytes were collected from aspirated porcine tertiary follicles. (biomedcentral.com)
  • To determine if the effect of TGF-beta1 on oocyte maturation involves transcription and/or translation, ovarian follicles were pre-treated with actinomycin D, a blocker of transcription, and cyclohexamide, an inhibitor of translation, and incubated with hCG or DHP, either alone or in combination with TGF-beta1 and oocyte maturation scored. (biomedcentral.com)
  • While deteriorate as the potential mother ages, compromising, the receptivity of the uterus and the ovarian reserve of for example, the function of the chromosomal apparatus follicles can explain the 'maternal age effect' in part, it is or the ability to scavenge reactive oxygen species known that age-related decline of a female's fertility is resulting from mitochondrial reactions ( also rooted in the quality and developmental potential of her oocytes. (gotomydoctor.com)
  • There were no differences between LT and control oocytes in the kinetics of MPF suppression by 6-DMAP. (jax.org)
  • Cryopreservation of mammalian oocytes has been successfully applied for long-term storage of surplus eggs in mammalian assisted reproductive technology (ART), including in humans. (molcells.org)
  • Our results indicate MIR21 is active and important during meiotic maturation of the oocyte. (biomedcentral.com)
  • The further research is needed to better understand the new important mechanisms that regulate diffcult aspects of oocyte meiotic maturation in mammals. (kiev.ua)
  • Thus, intrinsic factors governing the developmental potential that diminish during oocyte cryopreservation should be explored. (molcells.org)
  • Priming is the process by which the oocytes are primed with follicle-stimulating hormone (FSH) or human chorionic gonadotrophin (hCG) before retrieval. (wikipedia.org)
  • During oocyte growth, follicle stimulating hormone (FSH) stimulates production of estradiol-17β from the ovary. (biomedcentral.com)
  • Oocytes derived from aged cows, compared with those derived from their younger counterparts, exhibited high levels of abnormal fertilization and blastocysts with low total cell numbers. (elsevierpure.com)
  • This goal arises from the need of some patients to preserve their oocytes before arriving to a reproductively mature age, such as patients who need to undergo chemotherapy. (juniperpublishers.com)
  • Investigating the proteinsresulting from mRNA translation would reveal how far the levels of functionally available proteins correlate with mRNAs and would offernovel insights into the changes oocytes undergo during maternal ageing. (gotomydoctor.com)
  • A key step for this is to understands the interactions between somatic granulosa cells and the oocyte that are required for maturation and developmental competence. (juniperpublishers.com)
  • Oocytes within the ovarian follicle are surrounded by mural and cumulus granulosa cells, which perform both endocrine and developmental functions, respectively. (juniperpublishers.com)
  • The dominant follicle contains the mature oocyte. (wikipedia.org)
  • Vitrification of mouse GV oocytes using cryotop was more effective than straws, however both vitrification techniques did not improve the cleavage rate. (ijfs.ir)
  • Levels of maturation-promoting factor (MPF) in oocytes decline after vitrification, and this decline has been suggested as one of the main causes of low developmental competence resulting from cryoinjury. (molcells.org)
  • in particular, oocytes derived from aged cows show protein and mitochondrial dysfunction. (elsevierpure.com)
  • Thus, the maturing oocyte is reliant on processes such as post-transcriptional gene regulation (PTGR) to regulate the mRNA and protein repertoire. (biomedcentral.com)
  • Even though high rates of nuclear maturation have been reported with cryopreserved immature oocytes instead [ 1 , 3 ], the developmental capacity has been generally low [ 1 ]. (juniperpublishers.com)
  • This study may be an important supplement for the mechanism of oocyte meiotic resumption and provide new diagnostic targets and treatment clues for infertility patients with oocyte maturation disorder. (cambridge.org)
  • The oocytes are then cultured in media containing nutrients important for oocyte survival, such as gonadotrophins, growth factors and steroids. (wikipedia.org)
  • Such scheme of regulation of oocyte meiotic resumption is discussed (considered): the ac-tion of gonadotrophins, FSH and LH, causes increase the pro-duction of cAMP and subsequent activation of MAPK. (kiev.ua)
  • Therefore, we generated genome-wide methylation and transcriptome maps of size-selected, growing oocytes to capture the onset and progression of methylation. (biomedcentral.com)
  • Although more highly transcribed genes acquire methylation earlier, the major transitions in the oocyte transcriptome occur well before the de novo methylation phase, indicating that transcription is generally not rate limiting in conferring permissiveness to DNA methylation. (biomedcentral.com)
  • They include metabolic products highly associated with ovarian function - amino acids for regulating pH and osmolarity, lipids such fatty acids and cholesterols for oocyte maturation, and glucocorticoids for ovarian steroidogenesis. (biomedcentral.com)
  • The oocyte must maintain arrest at the diplotene stage until meiotic resumption occurs. (biomedcentral.com)
  • Oocyte arrest at the diplotene stage is maintained in part through the activity of phosphodiesterase enzymes that catalyze the hydrolysis of cyclic adenosine monophosphate (cAMP) into AMP [ 1 , 2 ]. (biomedcentral.com)
  • A critical difference between cryopreserving MII or GV stage oocytes centers on the importance of the intercellular contacts between germinal and somatic cells. (juniperpublishers.com)
  • Furthermore, we conclude that the classic features of ageing may not be transposed from somatic tissues to oocytes in a one-to-onefashion. (gotomydoctor.com)
  • Collected MII oocytes were vitrified and divided into four groups: untreated, 10 mM caffeine (CA), 10 μM MG132 (MG), and 10 mM caffeine +10 μM MG132 (CA+MG). After warming, the MPF activity of oocytes and their blastocyst formation and implantation rates in the CA, MG, and CA+MG groups were much higher than those in the untreated group. (molcells.org)
  • The gene expression profiles of aged cows showed high expression of genes related to oxidative phosphorylation, eIF4 and p70S6K signaling, and mitochondrial dysfunction in MII-stage oocytes. (elsevierpure.com)
  • By 1991, the first human pregnancy was recorded using IVM followed by IVF, and in 1994 the first birth using IVM oocytes from polycystic ovarian syndrome patients was recorded highlighting that PCOS patient's oocytes are capable of maturation. (wikipedia.org)
  • The low maturation rate of oocytes is an important reason for female infertility and failure of assisted pregnancy. (cambridge.org)
  • In vivo development was assessed after transfer of injected oocytes to the oviducts of recipient mares. (bioone.org)
  • Some mutations in oocytes lead to infertility in the mature organism, whereas others, over a long period of time, may eventually lead to the emergence of novel species or subspecies. (elifesciences.org)
  • The inability to transcribe mRNA during this stage of development and the probable necessity for post-transcriptional gene regulation (PTGR) suggests an important role for non-coding RNA in the maturing oocyte. (biomedcentral.com)
  • Whereas different FSH and LH effects on NO production in ovary are involved in the regulation of induction of oocyte meiotic resumption in mammals. (kiev.ua)
  • HS had nega- * Correspondence: [email protected] tive effects on oocyte maturation via down-regulation of Equal contributors the gene expression in steroid hormone synthesis or their National Engineering Laboratory for Animal Breeding, Key Laboratory of receptors. (sagepub.com)
  • Treatment with actinomycin D, a blocker of transcription, reduced the inhibitory effect of TGF-beta1 on DHP-induced oocyte maturation, indicating that the inhibitory action of TGF-beta1 is in part due to regulation of gene transcription. (biomedcentral.com)
  • The coordinate development of both granulosa cell types is necessary to fulfill oocyte requirements. (juniperpublishers.com)
  • AIPL1 was also proved to accumulate in the GV region of oocytes, and ZP3 deletion can significantly inhibit the aggregation of AIPL1 in the nuclear region. (cambridge.org)
  • Currently, the molecular mechanisms involved in induction of oocyte meiotic resumption in the pre-ovulatory follicle which may include (involve) the elimination of meiosis inhibiting factors and/or the accumulation or activation of oocyte matu-ration signals are actively studied. (kiev.ua)