• Usage of melatonin during in vitro fertilization (IVF) procedures has been found to improve oocyte quality, survival, and fecundity. (jrhm.org)
  • 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)
  • SECM technique may be a valuable tool for accurately assessing the quality of embryos and thereby contribute to improving outcomes associated with assisted reproduction, including human in vitro fertilization. (bioone.org)
  • Assisted reproductive techniques for canines: preservation of genetic material in domestic dogs [3] "Assisted reproductive techniques (ARTs), such as artificial insemination, in vitro fertilization, and cryopreservation of gametes/zygotes, have been developed to improve breeding and reproduction of livestock and for the treatment of human infertility. (edu.au)
  • The present review discusses methods to improve oocyte quality in older women and new stimulation protocols that may improve the number of mature oocytes retrieved during an in vitro fertilization cycle. (arvigen.com)
  • 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)
  • 11 Among women undergoing in vitro fertilization-embryo transfer in the United States, deliveries per oocyte retrieved decreased from 36.9 percent among women under the age of 35 years to 20.5 percent among women between the ages of 38 and 40 years and to 10.7 percent among women between the ages of 41 and 42 years. (ldysinger.com)
  • To ascertain whether the Kunming (KM) mouse is an available model for age-related decline in female fertility in human or not, oocytes from young (6-8 weeks), middle-aged (9 months) and aged (12 months) female mice were compared with respect to number of oocytes, frequency of in-vitro maturation (IVM) and in-vitro fertilization (IVF), and meiotic chromosome segregation and alignment. (cambridge.org)
  • Oocytes are highly specialized cells that undergo the unique processes of meiosis and fertilization and execute a molecular program for development [ 1 ]. (biomedcentral.com)
  • Hence, to date, an effective and simple proxy of oocyte quality parameters has not been established yet making difficult for an accurate assessment of the female gamete quality before fertilization. (biomedcentral.com)
  • In the oocyte, mitochondria play a central role in cellular metabolism providing energy for successful cytoplasm and nucleus maturation, fertilization, embryo development, calcium homeostasis, and apoptosis initiation. (biomedcentral.com)
  • At puberty the number of oocytes decreases even more to reach about 60,000 to 80,000 per ovary, and only about 500 mature oocytes will be produced during a woman's life, the others will undergo atresia(degeneration). (wikipedia.org)
  • The oocyte must maintain arrest at the diplotene stage until meiotic resumption occurs. (biomedcentral.com)
  • In addition, we determined that oocytes surrounded by their follicular cells expressing EGFR-Grb7 exhibit normal meiotic resumption. (bvsalud.org)
  • 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)
  • Second Polar Body (Discarded afterward) + Ovum Oocyte meiosis, important to all animal life cycles yet unlike all other instances of animal cell division, occurs completely without the aid of spindle-coordinating centrosomes. (wikipedia.org)
  • Oogonia enter meiosis during embryonic development, becoming oocytes. (wikipedia.org)
  • Meiosis begins with DNA replication and meiotic crossing over. (wikipedia.org)
  • Removal of the oocyte from the follicle causes meiosis to progress in the oocyte. (wikipedia.org)
  • As follicles grow, they acquire receptors for luteinizing hormone, a pituitary hormone that reinitiates meiosis in the oocyte and causes ovulation of a fertilizable egg. (wikipedia.org)
  • Because the granulosa cells and oocyte are connected by gap junctions, cyclic GMP also decreases in the oocyte, causing meiosis to resume. (wikipedia.org)
  • Xenopus oocytes are encompassed by a layer of follicular cells that contribute to oocyte growth and meiosis in relation to oocyte maturation. (bvsalud.org)
  • We found that oocytes deprotected from their surrounding layer of follicular cells and expressing the epidermal growth factor (EGF) receptor (EGFR) and the Grb7 adaptor undergo accelerated prophase I to metaphase II meiosis progression upon stimulation by EGF. (bvsalud.org)
  • In summary, our study provides further insight into the role of the follicular cell layer in oocyte meiosis progression. (bvsalud.org)
  • 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)
  • It is well known that c-Jun N-terminal kinase (JNK) plays pivotal roles in various mitotic events, but its function in mammalian oocyte meiosis remains unknown. (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)
  • Germinal vesicle breakdown (GVBD) occurs during oocyte meiotic maturation, a period when transcriptional processes are virtually inactive. (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 mean number of ovarian follicles, ovarian germinal vesicle oocytes and ovulated MII oocytes decreased significantly with maternal age. (cambridge.org)
  • Significant reduction of germinal vesicle (GV) and MII oocytes and significant increase of metaphase chromosome misalignment and premature chromatid segregation after meiotic maturation of oocytes, similar to human, presumably contribute to the decline in aged KM mice. (cambridge.org)
  • Understanding the biological functions of miRNAs in frozen maturated oocytes may provide a better understanding of embryonic development and a comparison of fertility conservation in female mammals. (bvsalud.org)
  • Endometriosis affects the number of retrieved oocytes but not early embryonic development and live birth: a retrospective analysis of 716 IVF cycles. (ivi-rmainnovation.com)
  • Maturation of the mammalian oocyte is a complex process involving internal checkpoints and bidirectional communication with the surrounding cumulus cells. (biomedcentral.com)
  • cRNA microinjection of full-length or truncated MAD2L1BP uncovered their discordant roles in driving the extrusion of polar body 1 (PB1) in mouse oocytes. (bvsalud.org)
  • It is developed from the primary oocyte by maturation. (wikipedia.org)
  • The succeeding phase of ootidogenesis occurs when the primary oocyte develops into an ootid. (wikipedia.org)
  • 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)
  • The granulosa cells produce a small molecule, cyclic GMP, that diffuses into the oocyte through the gap junctions. (wikipedia.org)
  • Mammalian oocytes are maintained in meiotic prophase arrest for a very long time-months in mice, years in humans. (wikipedia.org)
  • The endomitotic cycle (endomitosis) starts with a normal prophase (endoprophase), after which the chromosome contracts further (endometaphase), their sister chromatids separate from each other (endoanaphase) and decondense to assume the interphase nuclear structure, resulting in polyploid cells, with double the chromosome number (endopolyploidy) at the end of each cycle. (scielo.br)
  • Further, melatonin and its receptors play a significant role in antioxidant defense mechanism of ovary for follicular growth and maturation. (jrhm.org)
  • However, the effects of the interaction between follicular cells and the oocyte surface on meiotic processes are unclear. (bvsalud.org)
  • Here, we investigated Xenopus follicular cell function using oocyte signaling and heterologous-expressing capabilities. (bvsalud.org)
  • Furthermore, an O-GlcNAcylation increase (by inhibition of O-GlcNAcase), the glycosidase that removes O-GlcNAc moieties, or decrease (by inhibition of OGT) amplifies oocyte spindle defects when follicular cells are absent highlighting a control of the meiotic spindle by the OGT-O-GlcNAcase duo. (bvsalud.org)
  • Prior to the onset of menopause (10-15 y), menstrual cycles shorten and rapid follicular loss occurs because more oocytes are being recruited. (medscape.com)
  • In this study, by whole-exome sequencing (WES), we identified homozygous and compound heterozygous MAD2L1BP variants in three families with female patients diagnosed with primary infertility owing to oocyte metaphase I (MI) arrest. (bvsalud.org)
  • Initially the arrest is due to lack of sufficient cell cycle proteins to allow meiotic progression. (wikipedia.org)
  • However, as the oocyte grows, these proteins are synthesized, and meiotic arrest becomes dependent on cyclic AMP. (wikipedia.org)
  • Maintenance of meiotic arrest also depends on the presence of a multilayered complex of cells, known as a follicle, that surrounds the oocyte. (wikipedia.org)
  • In the oocyte, cyclic GMP prevents the breakdown of cyclic AMP by the phosphodiesterase PDE3, and thus maintains meiotic arrest. (wikipedia.org)
  • 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)
  • Human oocyte maturation arrest represents one of the severe conditions for female patients with primary infertility. (bvsalud.org)
  • Once the kinetochores of chromosomes are correctly attached to bipolar spindles and the SAC is satisfied, the MAD2L1BP, best known as p31comet, binds mitosis arrest deficient 2 (MAD2) and recruits the AAA+-ATPase TRIP13 to disassemble the mitotic checkpoint complex (MCC), leading to the cell-cycle progression. (bvsalud.org)
  • Together, our studies identified and characterized novel biallelic variants in MAD2L1BP responsible for human oocyte maturation arrest at MI, and thus prompted new therapeutic avenues for curing female primary infertility. (bvsalud.org)
  • The decreased quality of oocytes involves an increased rate of chromosomal aneuploidy with aging predominantly related to meiotic errors during oocyte maturation. (arvigen.com)
  • in 2015 showed that supplementation of CoQ10 in an aged animal model delayed decline in ovarian reserve, restored oocyte mitochondrial gene expression, and improved mitochondrial activity with a significant reduction in oocyte aneuploidy. (arvigen.com)
  • As atresia continues, both the number and quality of oocytes fall below a critical level, and the rate of aneuploidy increases - a finding that is related at least in part to problems of the meiotic spindle 15 , 16 resulting in nondisjunction. (ldysinger.com)
  • Gasic, S., Mihola, O. & Trachtulec, Z. Prdm9 deficiency of rat oocytes causes synapsis among non-homologous chromosomes and aneuploidy. (cuni.cz)
  • Oogenesis starts with the process of developing primary oocytes, which occurs via the transformation of oogonia into primary oocytes, a process called oocytogenesis. (wikipedia.org)
  • Female infants have 6 to 7 million oocytes at 20 weeks of gestation, when progressive atresia occurs, resulting in 1 to 2 million oocytes at birth, approximately 25,000 at the age of 37 years, and 1000 at the age of 51 years, the average age of natural menopause in the United States. (ldysinger.com)
  • Therefore, in future, melatonin can be implicated as preferable therapeutic especially in IVF and assisted reproductive techniques. (jrhm.org)
  • Although assisted reproductive techniques (ART) have helped to solve many infertility problems, they cause changes in the expression of miRNA and genes in oocytes and preimplantation embryos, and the effect of these changes on the future of offspring is unknown, and has caused concerns. (bvsalud.org)
  • Assisted Reproductive Techniques in Multiple Sclerosis: Recommendations from an Expert Panel. (biocruces.com)
  • The oocytes compete with one another to become the dominant follicle and eventually ovulate to be released as an egg capable of being fertilized. (medscape.com)
  • It has been hypothesized that in gonadal dysgenesis various deletions on the X chromosome cause such rapid atresia of oocytes 5 that few girls with this condition reach puberty with functioning ovaries. (ldysinger.com)
  • However, it is also possible that such genetic defects result in a smaller complement of oocytes during gonadal development. (ldysinger.com)
  • Cycle fecundability decreases as the number of oocytes decreases. (medscape.com)
  • The number of oocytes decreases to approximately 2-3 million at birth and decreases again to 300,000 by the time of puberty. (medscape.com)
  • In plants, polytene chromosomes have been observed in only a few species, and seemed to be restricted to ovary and immature seed tissues, e.g., in Phaseolus coccineus and P. vulgaris (Nagl, 1981), until relatively recently, when they were observed in the cells of the anther tapetum of Vigna unguiculata (Guerra and Carvalheira, 1994) and of some Phaseolus species (Carvalheira and Guerra, 1994). (scielo.br)
  • After the onset of puberty and menses, the female human ovary recruits at least 30-50 oocytes during each menstrual cycle. (medscape.com)
  • Polytene chromosomes are structures found in highly specialized tissues in some animal and plant species, which are amplified through successive cycles of endoreduplication, finally producing several copies of each chromosome. (scielo.br)
  • As a result, these aged mice had more oocytes with stimulation, the developmental potential of the oocytes was improved, and more offspring were born compared to old animals receiving placebo 1. (arvigen.com)
  • Currently, its estimation is predominantly based on morphological analysis, which is subjective and does not consistently reflect the developmental competence of the oocytes. (biomedcentral.com)
  • however, it is not per se sufficient to assure oocyte developmental competence [ 13 ]. (biomedcentral.com)
  • Inhibition of nuclear meiotic maturation via IBMX significantly increased MIR21 and decreased its target, PDCD4. (biomedcentral.com)
  • Among those, several candidate genes have been shown to control the early patterning and/or the late synaptic maturation of specific neuronal subpopulations controlling the balance between excitation and inhibition in the developing cortex and cerebellum. (neurotransmitter.net)
  • 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)
  • As a follow-up study, conditional disruption of the gene PDSS-2, resulting in isolated CoQ deficiency in the oocytes of young animals, resulted in phenotypic changes characteristic of oocyte mitochondrial dysfunction associated with aging. (arvigen.com)
  • Several physiological parameters, such as viability, mitochondrial activity, and reactive oxygen species (ROS) levels have been also reported as useful markers of oocyte quality in marine invertebrates. (biomedcentral.com)
  • In the endoreduplication cycle, the chromatid number is duplicated, but they do not segregate, and after various endoreduplication cycles, larger and thicker chromosomes are produced, called polytenics. (scielo.br)
  • Furthermore, the patient's oocytes carrying the mutated MAD2L1BP resumed polar body extrusion (PBE) when rescued by microinjection of full-length MAD2L1BP cRNAs. (bvsalud.org)
  • Male European seabass, already predominant (~ 70%) in cultured stocks, show a high incidence (20-30%) of precocious sexual maturation under current aquaculture practices, leading to important economic losses for the industry. (biomedcentral.com)
  • In seabass aquaculture, the high incidence (20 to 30%) of precocious sexual maturation in males during the first year of life places a critical restraint to production parameters. (biomedcentral.com)
  • Decline in the Number of Oocytes from Birth to Menopause. (ldysinger.com)
  • The decline in the number of oocytes begins at 20 weeks' gestation when the female fetus has approximately 6-7 million oogonia (largest lifetime endowment). (medscape.com)
  • Despite several recent studies investigating molecular markers related to oocyte quality, methods currently available for their determination pose various technical challenges and limitations. (biomedcentral.com)
  • Injection of myc-tagged JNK2α1 mRNA into oocytes also revealed its localization on spindle poles. (cambridge.org)
  • Oocytes were collected from slaughterhouse-derived ovaries, matured in vitro, and injected with frozen-thawed stallion sperm. (bioone.org)
  • When ZP3 is knocked down, lamin A will be partially transferred to the nucleus of oocytes. (cambridge.org)
  • 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)
  • The rate of IVM in oocytes from young mice (73.9%) was less significantly than that in oocytes from middle-aged and aged mice (86.1% and 84.4%, respectively). (cambridge.org)
  • Immunocytochemical analysis showed that ageing caused a significantly higher rate (49.3%) of chromosome misalignment than that (15.7%) of the young mice. (cambridge.org)
  • In view of the known modulation of reproductive development by swimming exercise in other teleost species, we aimed at investigating the effects of sustained swimming on reproductive development in seabass males during the first year of life in order to determine if swimming could potentially reduce precocious sexual maturation. (biomedcentral.com)
  • 1 , 2 The mechanism underlying this process is poorly understood and involves multiple factors encoded by genes on the X chromosome, as well as on autosomes. (ldysinger.com)
  • A Feature Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for future research directions and describes possible research applications. (mdpi.com)
  • It is commonly believed that, when oocytogenesis is complete, no additional primary oocytes are created, in contrast to the male process of spermatogenesis, where gametocytes are continuously created. (wikipedia.org)
  • The low maturation rate of oocytes is an important reason for female infertility and failure of assisted pregnancy. (cambridge.org)
  • Thus, the maturing oocyte is reliant on processes such as post-transcriptional gene regulation (PTGR) to regulate the mRNA and protein repertoire. (biomedcentral.com)
  • 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)
  • MicroRNAs (miRNAs) are small non-encoding RNAs that actively regulate biological and physiological processes, and play an important role in regulating gene expression in all cells, especially in most animal cells, including oocytes and embryos. (bvsalud.org)
  • The mouse Tzfp gene, mapped to chromosome 7 B2-B3, encodes a 465-amino acid transcription factor containing a conserved N-terminal BTB/POZ domain and three C-terminal PLZF-like C(2)H(2) zinc fingers. (lookformedical.com)
  • We are investigating how female lymphocytes maintain X-chromosome Inactivation, which is an epigenetic process responsible for equalizing gene expression between sexes. (upenn.edu)
  • Nevertheless, the complexity of the techniques applied to assess gene expression and protein profile is a major bottleneck for the use of molecular markers in the oocyte quality assessment [ 12 ]. (biomedcentral.com)
  • Despite considerable ongoing effort toward the identification of chromosome regions affected in autism and the characterization of many potential gene candidates, only a few genes have been reproducibly shown to display specific mutations that segregate with autism, likely because of the complex polygenic nature of this syndrome. (neurotransmitter.net)
  • Our laboratory investigates X-chromosome Inactivation, and how this epigenetic process contributes to female-biased autoimmunity. (upenn.edu)
  • Works in various organisms have revealed that the kinase is involved in centrosome separation, duplication and maturation as well as in bipolar spindle assembly and stability. (lookformedical.com)
  • The fact that live-birth rates from oocyte donation in older women are consistent with the age of the donor suggests that oocyte quality is the major factor responsible for reduced fecundability with aging. (arvigen.com)
  • Since recent clinical studies have indicated that dehydroepiandrosterone (DHEA) supplementation may reverse the problem of oocyte quality, this review of the literature was undertaken in an attempt to find an explanation of why this is effective? (biomedcentral.com)
  • Oocyte quality has been defined as the ability of oocytes to be fertilized and produce viable progeny. (biomedcentral.com)
  • Many investigations have been designed to gain new insights into the mechanisms underlying oocyte quality based on a differential analysis applied to molecular, biochemical, transcriptomic, or proteomic data. (biomedcentral.com)
  • Oocytes were collected from aspirated porcine tertiary follicles. (biomedcentral.com)
  • The progressive loss of oocytes from fetal life through menopause is a normal process. (ldysinger.com)
  • X-chromosome Inactivation silences one X-chromosome in female cells, and this process is initiated and maintained by the long noncoding RNA Xist. (upenn.edu)
  • These oocytes are protected from abnormal meiotic spindle formation through the recruitment of O-GlcNAcylated Grb7, and OGT (O-GlcNAc transferase), the enzyme responsible for O-GlcNAcylation processes, in the integrin ß1-EGFR complex. (bvsalud.org)
  • In this paper some aspects of the occurrence of plant polytenes will be summarized along with the structure and function of these chromosomes. (scielo.br)
  • The adenylyl cyclase is kept active by a constitutively active G-protein-coupled receptor known as GPR3 and a G-protein, Gs, also present in the oocyte membrane. (wikipedia.org)