Journal articles on the topic 'Oocyte differentiation'
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1
Budna, Joanna, Artur Bryja, Piotr Celichowski, Rotem Kahan, Wiesława Kranc, Sylwia Ciesiółka, Marta Rybska, et al. "Genes of cellular components of morphogenesis in porcine oocytes before and after IVM." Reproduction 154, no. 4 (October 2017): 535–45. http://dx.doi.org/10.1530/rep-17-0367.
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Proper oocyte maturation in mammals produces an oocyte capable of monospermic fertilization and embryo preimplantation. The cumulus-oocyte complexes (COCs), surrounding an oocyte, play a significant role in oocyte maturation. During this process, when the COCs undergo cumulus expansion wherein tightly compact cumulus cells (CCs) form a dispersed structure, permanent biochemical and molecular modifications occur in the maturing oocytes, indicating that the gene expression between immature and mature oocytes differs significantly. This study focuses on the genes responsible for the cellular components of morphogenesis within the developing oocyte. Brilliant cresyl blue (BCB) was used to determine the developmental capability of porcine oocytes. The immature oocytes (GV stage) were compared with matured oocytes (MII stage), using microarray and qRT-PCR analysis to track changes in the genetic expression profile of transcriptome genes. The data showed substantial upregulation of genes influencing oocyte’s morphology, cellular migration and adhesion, intracellular communication, as well as plasticity of nervous system. Conversely, downregulation involved genes related to microtubule reorganization, regulation of adhesion, proliferation, migration and cell differentiation processes in oocytes. This suggests that most genes recruited in morphogenesis in porcine oocytein vitro,may have cellular maturational capability, since they have a higher level of expression before the oocyte’s matured form. It shows the process of oocyte maturation and developmental capacity is orchestrated by significant cellular modifications during morphogenesis.
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Faizah, Zakiyatul, and Raden Haryanto Aswin. "EXPRESSION OF TRANSFORMING GROWTH FACTOR-beta AND GROWTH DIFFERENTIATION FACTOR-9 ON SHEEP OOCYTES VITRIFIED AFTER AND BEFORE IN VITRO MATURATION." Jurnal Veteriner 22, no. 1 (March 31, 2021): 109–15. http://dx.doi.org/10.19087/jveteriner.2021.22.1.109.
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Oocyte vitrification today became a hope to preserve fertility. Its was a major challenge because of oocyte characteristic in every phase. Immature oocytes were more sensitive to osmotic stress and the membrane wes less stable while mature oocyte have spindles that were very susceptible to temperature decrease. The study aim to compare the effect of vitrification before and after in vitro maturation to the expression TGF beta and GDF9. Oocyte of ewes divided into control groups (K0), K1 maturation prior vitrification, K2 vitrification prior maturation. Vitrification begins with washing oocytes in PBS supplemented of 20%serum for 1-2 minutes, followed by equilibration medium PBS + 20% serum + 10% ethylene glycol for 10-14 minutes, then transferred to 20% serum + PBS + 0.5 M sucrose + 15% ethylene glycol + PROH 15% for 25-30 seconds. Thawing was processed by in the media: 1). PBS + 20% serum + 0.5 M sucrose, 2).PBS + 20% serum + 0.25 M sucrose, and 3).PBS + 20% serum + 0.1 M sucrose. Immunocytochemical stain was performed to evaluate TGF ? and GDF9 expression. Remmele scale index (IRS) was used to read the result. TGF beta expression both in oocyte and cummulus of K0 and K1 was significant statistically difference (p<0.05) compare with K2. GDF9 expression both in oocyte and cummulus of K0 and K1 was significant statistically difference (p<0.05) compare with K2. We concluded that immature oocyte give better expression of TGF â and GDF9 than mature oocyte.
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Moncrieff, Lisa, Ievgeniia Kocherova, Artur Bryja, Wiesława Kranc, Joanna Perek, Magdalena Kulus, Michal Jeseta, et al. "Transcriptomic profile of genes encoding proteins responsible for regulation of cells differentiation and neurogenesis in vivo and in vitro – an oocyte model approach." Medical Journal of Cell Biology 8, no. 1 (April 29, 2020): 1–11. http://dx.doi.org/10.2478/acb-2020-0001.
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AbstractThe growth and development of the oocyte is essential for the ovarian follicle. Cumulus cells (CCs) - a population of granulosa cells - exchange metabolites, proteins and oocyte-derived paracrine factors with the oocyte through gap junctions, to contribute to the competency and health of the oocyte. This bi-directional communication of the cumulus-oocyte complex could be better understood through the micro-analysis of a porcine oocyte gene expression before in vitro maturation (IVM) and after. Additionally, the study of the somatic and gamete cells differentiation capability into neuronal lineage would be promising for future stem cell research as granulosa cells are easily accessible waste material from in vitro fertilization (IVF) procedures. Therefore, in this study, the oocytes of 45 pubertal Landrace gilts were isolated and the protein expression of the COCs were analyzed through micro-analysis techniques. Genes belonging to two ontological groups: neuron differentiation and negative regulation of cell differentiation have been identified which have roles in proliferation, migration and differentiation. Twenty identified porcine oocyte genes (VEGFA, BTG2, MCOLN3, EGR2, TGFBR3, GJA1, FST, CTNNA2, RTN4, MDGA1, KIT, RYK, NOTCH2, RORA, SMAD4, ITGB1, SEMA5A, SMARCA1, WWTR1 and APP) were found to be down-regulated after the transition of IVM compared to in vitro. These results could be applied as gene markers for the proliferation, migration and differentiation occurring in the bi-directional communication between the oocyte and CCs.Running title: Differentiation and neurogenesis in oocyte cells
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Theurkauf, W. E., B. M. Alberts, Y. N. Jan, and T. A. Jongens. "A central role for microtubules in the differentiation of Drosophila oocytes." Development 118, no. 4 (August 1, 1993): 1169–80. http://dx.doi.org/10.1242/dev.118.4.1169.
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Drosophila oocytes develop within cysts containing 16 cells that are interconnected by cytoplasmic bridges. Although the cysts are syncytial, the 16 cells differentiate to form a single oocyte and 15 nurse cells, and several mRNAs that are synthesized in the nurse cells accumulate specifically in the oocyte. To gain insight into the mechanisms that generate the cytoplasmic asymmetry within these cysts, we have examined cytoskeletal organization during oocyte differentiation. Shortly after formation of the 16 cell cysts, a prominent microtubule organizing center (MTOC) is established within the syncytial cytoplasm, and at the time the oocyte is determined, a single microtubule cytoskeleton connects the oocyte with the remaining 15 cells of each cyst. Recessive mutations at the Bicaudal-D (Bic-D) and egalitarian (egl) loci, which block oocyte differentiation, disrupt formation and maintenance of this polarized microtubule cytoskeleton. Microtubule assembly-inhibitors phenocopy these mutations, and prevent oocyte-specific accumulation of oskar, cyclin B and 65F mRNAs. We propose that formation of the polarized microtubule cytoskeleton is required for oocyte differentiation, and that this structure mediates the asymmetric accumulation of mRNAs within the syncytial cysts.
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Dragovic, Rebecca A., Lesley J. Ritter, Samantha J. Schulz, Fred Amato, David T. Armstrong, and Robert B. Gilchrist. "Role of Oocyte-Secreted Growth Differentiation Factor 9 in the Regulation of Mouse Cumulus Expansion." Endocrinology 146, no. 6 (June 1, 2005): 2798–806. http://dx.doi.org/10.1210/en.2005-0098.
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Abstract Oocyte-secreted factors are required for expansion of the mouse cumulus-oocyte complex, which is necessary for ovulation. Oocyte-secreted growth differentiation factor 9 (GDF9) signals through the bone morphogenetic protein receptor II and is currently the primary candidate molecule for the cumulus-expansion enabling factor. This study was conducted to determine whether GDF9 is the mouse cumulus-expansion enabling factor. Cumulus-oocyte complexes were collected from mice, and the oocyte was microsurgically removed to generate an oocytectomized (OOX) complex. OOX complexes treated with FSH alone or recombinant mouse GDF9 alone failed to expand, whereas expansion was induced in the presence of FSH by GDF9, TGFβ1, or coculture with oocytes. A specific GDF9-neutralizing antibody, mAb-GDF9–53, neutralized the expansion of OOX complexes in response to GDF9 but not the expansion of OOX complexes cocultured with oocytes. Using real-time RT-PCR, hyaluronan synthase 2 (HAS2) mRNA expression by OOXs was up-regulated 4- to 6-fold by oocytes and GDF9. Monoclonal neutralizing antibody-GDF9–53 attenuated GDF9-induced OOX HAS2 expression but not oocyte-induced HAS2 expression. A TGFβ antagonist neutralized TGFβ-induced, but not oocyte-induced, expansion of OOX complexes, and when combined with monoclonal neutralizing antibody-GDF9–53 also failed to neutralize oocyte-induced expansion. Furthermore, a soluble portion of the bone morphogenetic protein receptor II extracellular domain, which is a known GDF9 antagonist, completely antagonized GDF9-induced expansion but only partially neutralized oocyte-induced expansion. This study provides further evidence that like TGFβ, GDF9 can enable FSH-induced cumulus expansion, but more importantly, demonstrates that neither GDF9 nor TGFβ alone, nor the two in unison, account for the critical oocyte-secreted factors regulating mouse cumulus expansion.
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Sirard, M. A. "247 THE IMPORTANCE OF FOLLICULAR DIFFERENTIATION TO OBTAIN FULLY COMPETENT BOVINE OOCYTES." Reproduction, Fertility and Development 28, no. 2 (2016): 256. http://dx.doi.org/10.1071/rdv28n2ab247.
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Making an oocyte with the capacity to form a Day-7 embryo that will implant and produce a live healthy calf is a long and complex process. Since the beginning of bovine IVF, it has been clear that the follicle from which an oocyte is obtained is the most important factor to predict outcome. The blastocyst rate is above 75% with in vivo-matured oocytes, but success varies greatly following in vitro maturation, depending more on follicular status than size. Indeed, aspirating oocytes from non-preovulatory follicles can result in 30% blastocyst development following fertilization but rarely more, unless the follicle is selected. Follicles leading to improved development are either early atretic or exposed to FSH withdrawal. If no exogenous FSH is given, natural early atresia will occur the day after the dominant follicle is selected, but will be limited to a few follicles per wave. If FSH is given to generate a wave of dominant follicles, and then withdrawn, most of the follicles will continue growth and differentiation under basal LH and a maximal oocyte quality will be reached between Day 2 and 3 after the last FSH injection. Under these conditions, the oocyte has the right cascade of signaling to condense its chromatin and to prepare for fertilization. Oocytes obtained from less-prepared follicles are of lower quality, as demonstrated by lower blastocyst rates, lower blastocyst quality, lower implantation rates, and higher abortion rates. Genomic analysis of embryos generated from slaughterhouse-derived oocytes indicates a progressive dysfunction in direct link with the in vitro exposure time. The best way to minimize in vitro-related stress is to begin with a competent oocyte and the best demonstration of that is when some animals (treated with FSH and then coasted) generate 100% blastocyst rate for a recovery of more than 5 oocytes, indicating that the initial quality of oocytes is not much affected by the in vitro culture. It is surprising that blastocyst rates following coasting and in vitro maturation can surpass that observed with Day-7 embryo collections based on the number of ovulations. Finally, new epigenetic analysis will progressively unravel differences of oocytes obtained from different sources and will become an important research tool to assess follicular conditions that will lead to minimal culture stress and optimal embryo quality. If epigenetic programming of the embryo depends on its capacity to deal with the stress created by culture, as has been shown in other species, the initial quality of the oocyte will potentially impact the health status of the newborn calf and resulting adult.
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Dragovic, R. A., L. J. Ritter, F. Amato, S. J. Scott, M. Cranfield, N. P. Groome, D. T. Armstrong, and R. B. Gilchrist. "251.Regulation of mouse cumulus expansion by oocyte-secreted growth differentiation factor-9 (GDF-9)." Reproduction, Fertility and Development 16, no. 9 (2004): 251. http://dx.doi.org/10.1071/srb04abs251.
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Oocyte paracrine signalling is necessary for mouse cumulus cell expansion, an important preovulatory process. The oocyte-secreted factor growth differentiation factor-9 (GDF-9) signals through the bone morphogenetic protein receptor-II (BMPR-II) and is currently the primary candidate molecule for the cumulus expansion enabling factor (CEEF). The present study was conducted to determine whether in the mouse GDF-9 is the CEEF. Cumulus oocyte complexes (COC) were collected from eCG-primed mice and the oocyte was microsurgically removed to generate an oocytectomised complex (OOX). An established scoring system was used to measure FSH-induced cumulus expansion; 0 (no expansion) to +4 (maximum expansion). OOX complexes treated with FSH alone failed to expand (score: 0), whereas expansion was significantly (P�<�0.05) induced by either recombinant mouse GDF-9 (score; mean +/– SEM: 2.7 +/– 0.1), recombinant TGF-μ1 (score: 2.6 +/– 0.2) or co-culture with oocytes (score: 2.3 +/– 0.2). A GDF-9 neutralising antibody mAb-53, raised against hGDF-9, was effective in neutralising the response of OOX complexes to GDF-9 (score: 0.1 +/– 0.1), but had no significant effect on the expansion of OOX complexes co-cultured with oocytes (score: 2.3 +/– 0.2). Likewise, a TGF-μ antagonist neutralised (P�<�0.05) TGF-μ-induced, but not oocyte-induced, expansion of OOX complexes. A soluble portion of the BMPR-II ectodomain, a known GDF-9 antagonist, failed to neutralise oocyte-induced cumulus expansion (P�>�0.05) at the highest dose implying that BMPR-II is not a critical receptor involved in regulating cumulus expansion. Using real-time RT-PCR, hyaluronan synthase-2 (HAS2) mRNA expression by OOXs was upregulated 6- to 7-fold by oocytes and GDF-9. The GDF-9 neutralising antibody mAb-53, partially neutralised GDF-9-induced OOX HAS2 expression, but not oocyte-induced HAS2 expression. This study provides evidence that like TGF-μ1, GDF-9 can enable FSH-induced cumulus expansion, however more importantly demonstrates that neither GDF-9 nor TGF-μ1 alone account for the crucial oocyte-secreted factor regulating cumulus expansion in the mouse.
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Guo, Jing, Teng Zhang, Yueshuai Guo, Tao Sun, Hui Li, Xiaoyun Zhang, Hong Yin, et al. "Oocyte stage-specific effects of MTOR determine granulosa cell fate and oocyte quality in mice." Proceedings of the National Academy of Sciences 115, no. 23 (May 21, 2018): E5326—E5333. http://dx.doi.org/10.1073/pnas.1800352115.
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MTOR (mechanistic target of rapamycin) is a widely recognized integrator of signals and pathways key for cellular metabolism, proliferation, and differentiation. Here we show that conditional knockout (cKO) of Mtor in either primordial or growing oocytes caused infertility but differentially affected oocyte quality, granulosa cell fate, and follicular development. cKO of Mtor in nongrowing primordial oocytes caused defective follicular development leading to progressive degeneration of oocytes and loss of granulosa cell identity coincident with the acquisition of immature Sertoli cell-like characteristics. Although Mtor was deleted at the primordial oocyte stage, DNA damage accumulated in oocytes during their later growth, and there was a marked alteration of the transcriptome in the few oocytes that achieved the fully grown stage. Although oocyte quality and fertility were also compromised when Mtor was deleted after oocytes had begun to grow, these occurred without overtly affecting folliculogenesis or the oocyte transcriptome. Nevertheless, there was a significant change in a cohort of proteins in mature oocytes. In particular, down-regulation of PRC1 (protein regulator of cytokinesis 1) impaired completion of the first meiotic division. Therefore, MTOR-dependent pathways in primordial or growing oocytes differentially affected downstream processes including follicular development, sex-specific identity of early granulosa cells, maintenance of oocyte genome integrity, oocyte gene expression, meiosis, and preimplantation developmental competence.
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Uchida, Daisuke, Michiaki Yamashita, Takeshi Kitano, and Taisen Iguchi. "Oocyte apoptosis during the transition from ovary-like tissue to testes during sex differentiation of juvenile zebrafish." Journal of Experimental Biology 205, no. 6 (March 15, 2002): 711–18. http://dx.doi.org/10.1242/jeb.205.6.711.
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SUMMARY Large numbers of apoptotic early diplotene oocytes were observed during the transition from ovary-like undifferentiated gonadal tissue to testes during sex differentiation in presumptive males of the zebrafish (Danio rerio). The percentage of terminal-deoxynucleotidyl-transferase-mediated dUTP nick-end labelling (TUNEL)-positive apoptotic oocytes in the gonads of presumptive males was approximately eight- to 12-fold higher than in genetic all-females. By 29 days post-hatching, all oocytes had disappeared from the gonads of presumptive males. In these males, we also observed apoptotic somatic cells in the ovarian cavity between 23 and 35 days post-hatching. Therefore, the disappearance of oocytes and the decomposition of the ovarian cavity caused by apoptosis during sex differentiation were male-specific events. In genetic all-females, apoptosis in a proportion of early diplotene oocytes was found in the undifferentiated gonads at 15–19 days post-hatching, probably as a result of programmed oocyte loss during ovarian development. These findings suggest that oocyte apoptosis is the mechanism of testicular and ovarian differentiation in zebrafish.
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Chen, Ying, Wendy N. Jefferson, Retha R. Newbold, Elizabeth Padilla-Banks, and Melissa E. Pepling. "Estradiol, Progesterone, and Genistein Inhibit Oocyte Nest Breakdown and Primordial Follicle Assembly in the Neonatal Mouse Ovary in Vitro and in Vivo." Endocrinology 148, no. 8 (August 1, 2007): 3580–90. http://dx.doi.org/10.1210/en.2007-0088.
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In developing mouse ovaries, oocytes develop as clusters of cells called nests or germ cell cysts. Shortly after birth, oocyte nests dissociate and granulosa cells surround individual oocytes forming primordial follicles. At the same time, two thirds of the oocytes die by apoptosis, but the link between oocyte nest breakdown and oocyte death is unclear. Although mechanisms controlling breakdown of nests into individual oocytes and selection of oocytes for survival are currently unknown, steroid hormones may play a role. Treatment of neonatal mice with natural or synthetic estrogens results in abnormal multiple oocyte follicles in adult ovaries. Neonatal genistein treatment inhibits nest breakdown suggesting multiple oocyte follicles are nests that did not break down. Here we investigated the role of estrogen signaling in nest breakdown and oocyte survival. We characterized an ovary organ culture system that recapitulates nest breakdown, reduction in oocyte number, primordial follicle assembly, and follicle growth in vitro. We found that estradiol, progesterone, and genistein inhibit nest breakdown and primordial follicle assembly but have no effect on oocyte number both in organ culture and in vivo. Fetal ovaries, removed from their normal environment of high levels of pregnancy hormones, underwent premature nest breakdown and oocyte loss that was rescued by addition of estradiol or progesterone. Our results implicate hormone signaling in ovarian differentiation with decreased estrogen and progesterone at birth as the primary signal to initiate oocyte nest breakdown and follicle assembly. These findings also provide insight into the mechanism of multiple oocyte follicle formation.
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Czolowska, Renata, and Andrzej K. Tarkowski. "First meiosis of early dictyate nuclei from primordial oocytes in mature and activated mouse oocytes." Zygote 4, no. 1 (February 1996): 73–80. http://dx.doi.org/10.1017/s0967199400002914.
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SummaryNuclei of diplotene (dictyate) primordial oocytes (PO) were transferred to metaphase II oocytes and to activated mouse oocytes using cell fusion techniques. In a metaphase II oocyte, the PO nucleus condenses within 2–3 h to bivalents which become arranged on the first meiotic spindle. After oocyte activation, homologous chromosomes segregate between the oocyte and the first polar body, and a diploid pronucleus-like nucleus reforms from the one set of dyads. This nucleus condenses in the first embryonic mitosis into 40 ‘somatic’ chromosomes which coexist in the common metaphase plate with 20 somatic chromosomes originating from the female pronucleus. Shortening of the time between fusion and activation to about 1 h prevents bivalent differentiation. The PO nucleus condenses only partially and reforms, after oocyte activation, a pronucleus-like nucleus. This nucleus gives rise at the first embryonic mitosis to 20 bivalents which coexist with 20 somatic chromosomes originating from the female pronucleus. A PO nucleus introduced into an activated egg completes the first cell cycle as an intact interphase nucleus. It never condenses in the first embryonic mitosis into bivalents, and undergoes only initial condensation (preceding bivalent differentiation). These results indicate that: (1) condensation into bivalents, meiotic spindle formation and first meiotic division can be greatly accelerated by the introduction of an early diplotene (dictyate) oocyte nucleus into a metaphase II oocyte, and (2) depending on whether the diplotene nucleus enters the first embryonic (mitotic) cell cycle after just initiating or after completing the first meiosis, it gives rise at the first cleavage division to meiotic (bivalents) or ‘somatic’ chromosomes respectively.
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Piotrowska, H., B. Kempisty, P. Sosinska, S. Ciesiolka, D. Bukowska, P. Antosik, M. Rybska, KP Brussow, M. Nowicki, and M. Zabel. "The role of TGF superfamily gene expression in the regulation of folliculogenesis and oogenesis in mammals: a review." Veterinární Medicína 58, No. 10 (November 21, 2013): 505–15. http://dx.doi.org/10.17221/7082-vetmed.
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The normal differentiation of follicles from the preantral to the antral stage is regulated by the synthesis and secretion of several important growth factors. Moreover, the proper growth and development of the oocyte and its surrounding somatic granulosa-cumulus cells is accomplished through the activation of paracrine pathways that form a specific cross-talk between the gamete and somatic cells. It has been shown that several growth factors produced by the ovary are responsible for the proper growth and development of follicles. The developmental competence of mammalian oocytes (also termed developmental potency) is defined as the ability of female gametes to reach maturation (the MII stage) and achieve successful monospermic fertilisation. Proper oocyte development during folliculo- and oogenesis also plays a critical role in normal zygote and blastocyst formation, as well as implantation and the birth of healthy offspring. Several molecular markers have been used to determine the developmental potency both of oocytes and follicles. The most important markers include transforming growth factor beta superfamily genes (TGFB), and the genes in this family have been found to play a crucial role in oocyte differentiation during oogenesis and folliculogenesis. In the present review, we summarise several molecular aspects concerning the assessment of mammalian oocyte developmental competence. In addition, we present the molecular mechanisms which activate important growth factors within the TGFB superfamily that have been shown to regulate not only follicle development but also oocyte maturation.
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Nogueira, D., R. Cortvrindt, B. Everaerdt, and J. Smitz. "Effects of long-term in vitro exposure to phosphodiesterase type-3 inhibitors on follicle and oocyte development." Reproduction 130, no. 2 (August 2005): 177–86. http://dx.doi.org/10.1530/rep.1.00652.
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Germinal vesicle (GV)-stage oocytes retrieved from antral follicles undergo nuclear maturation in vitro, which typically occurs prior to cytoplasmic maturation. Short-term culture with meiotic inhibitors has been applied to arrest oocytes at the GV stage aiming to synchronize nuclear and ooplasmic maturity. However, the results obtained are still far from the in vivo situation. In order to acquire competence, immature oocytes may require meiotic arrest in vitro for a more extended period. The phosphodiesterase type 3-inhibitor (PDE3-I) is a potent meiotic arrester. The effects of a prolonged culture with PDE3-I on oocyte quality prior to and after reversal from the inhibition are not known. This study tested the impact of long-term in vitro exposure of two PDE3-Is, org9935 and cilostamide, on oocytes using a mouse follicle culture model. The results showed that PDE3-I (maximum of 10 μM) during a 12-day culture of follicle-enclosed oocytes did not alter somatic cell proliferation, differentiation or follicle survival. In addition, the steroid production profile was not significantly modified by a 12-day exposure to PDE3-I. The recombinant human chorionic gonadotrophin/recombinant human epidermal growth factor stimulus induced a characteristic normal progesterone peak of luteinization and normal mucification of the cumulus cells, while the enclosed oocyte remained blocked at the GV stage. In vitro maturation of denuded or cumulus-enclosed oocytes derived from org9935- or cilostamide-exposed follicles progressed through meiosis and formed morphologically normal meiotic spindles with chromosomes properly aligned at the equator. In conclusion, long-term culture with PDE3-I was harmless to somatic cell function, differentiation, oocyte growth and maturation. Our results suggested that PDE3-I can be applied when extended oocyte culture is required to improve ooplasmic maturation.
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Wang, Gaifang, and Maryam Farzaneh. "Mini Review; Differentiation of Human Pluripotent Stem Cells into Oocytes." Current Stem Cell Research & Therapy 15, no. 4 (June 16, 2020): 301–7. http://dx.doi.org/10.2174/1574888x15666200116100121.
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Primary Ovarian Insufficiency (POI) is one of the main diseases causing female infertility that occurs in about 1% of women between 30-40 years of age. There are few effective methods for the treatment of women with POI. In the past few years, stem cell-based therapy as one of the most highly investigated new therapies has emerged as a promising strategy for the treatment of POI. Human pluripotent stem cells (hPSCs) can self-renew indefinitely and differentiate into any type of cell. Human Embryonic Stem Cells (hESCs) as a type of pluripotent stem cells are the most powerful candidate for the treatment of POI. Human-induced Pluripotent Stem Cells (hiPSCs) are derived from adult somatic cells by the treatment with exogenous defined factors to create an embryonic-like pluripotent state. Both hiPSCs and hESCs can proliferate and give rise to ectodermal, mesodermal, endodermal, and germ cell lineages. After ovarian stimulation, the number of available oocytes is limited and the yield of total oocytes with high quality is low. Therefore, a robust and reproducible in-vitro culture system that supports the differentiation of human oocytes from PSCs is necessary. Very few studies have focused on the derivation of oocyte-like cells from hiPSCs and the details of hPSCs differentiation into oocytes have not been fully investigated. Therefore, in this review, we focus on the differentiation potential of hPSCs into human oocyte-like cells.
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Yoon, Junchul David, Seon-Ung Hwang, Mirae Kim, Yubyeol Jeon, and Sang-Hwan Hyun. "Growth differentiation factor 8 regulates SMAD2/3 signaling and improves oocyte quality during porcine oocyte maturation in vitro†." Biology of Reproduction 101, no. 1 (April 20, 2019): 63–75. http://dx.doi.org/10.1093/biolre/ioz066.
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Abstract Growth differentiation factor 8 (GDF8), also known as myostatin, is a member of the transforming growth factor-β (TGF-β) family and has been identified as a strong physiological regulator of muscle differentiation. Recently, the functional role of GDF8 in reproductive organs has received increased interest following its detection in the human placenta and uterus. To investigate the effects of GDF8 during porcine oocyte in vitro maturation (IVM), we assessed the quality of matured oocytes. Furthermore, we investigated the specific gene transcription and protein activation levels in oocytes and cumulus cells after IVM and subsequent embryonic development after in vitro fertilization and parthenogenetic activation. Prior to these experiments, the concentration of GDF8 in porcine follicular fluid was determined. During the entire IVM period, 1.3 ng/mL GDF8 and its signaling inhibitor SB431542 (SB) at 5 μM were added as control, SB, SB + GDF8, and GDF8 groups, respectively. Our results demonstrate that supplementation with GDF8 during porcine oocyte IVM enhanced both meiotic and cytoplasmic maturation, with altered transcriptional patterns, via activation of Sma- and Mad-related protein 2/3 (SMAD2/3). Using the pharmacological inhibitor SB431542, we demonstrated that inhibition of GDF8-induced Smad2/3 signaling reduces matured oocyte quality. In conclusion, for the first time, we demonstrated paracrine factor GDF8 in porcine follicular fluid in vivo. Furthermore, we showed that GDF8 supplementation improved mature oocyte quality by regulating p38 mitogen-activated protein kinase phosphorylation and intracellular glutathione and reactive oxygen species levels during porcine IVM.
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Pan, Bo, Derek Toms, Wei Shen, and Julang Li. "MicroRNA-378 regulates oocyte maturation via the suppression of aromatase in porcine cumulus cells." American Journal of Physiology-Endocrinology and Metabolism 308, no. 6 (March 15, 2015): E525—E534. http://dx.doi.org/10.1152/ajpendo.00480.2014.
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We sought to investigate whether miR-378 plays a role in cumulus cells and whether the manipulation of miRNA levels in cumulus cells influences oocyte maturation in vitro. Cumulus-oocyte complexes (COCs) from ovarian follicles had significantly lower levels of precursor and mature miR-378 in cumulus cells surrounding metaphase II (MII) oocytes than cumulus cells surrounding germinal vesicle (GV) oocytes, suggesting a possible role of miR-378 during COC maturation. Overexpression of miR-378 in cumulus cells impaired expansion and decreased expression of genes associated with expansion ( HAS2, PTGS2) and oocyte maturation ( CX43, ADAMTS1, PGR). Cumulus cell expression of miR-378 also suppressed oocyte progression from the GV to MII stage (from 54 ± 2.7 to 31 ± 5.1%), accompanied by a decrease of growth differentiation factor 9 ( GDF9), bone morphogenetic protein 15 ( BMP15), zona pellucida 3 ( ZP3), and CX37 in the oocytes. Subsequent in vitro fertilization resulted in fewer oocytes from COCs overexpressing miR-378 reaching the blastocyst stage (7.3 ± 0.7 vs. 16.6 ± 0.5%). miR-378 knockdown led to increased cumulus expansion and oocyte progression to MII, confirming a specific effect of miR-378 in suppressing COC maturation. Aromatase (CYP19A1) expression in cumulus cells was also inhibited by miR-378, leading to a significant decrease in estradiol production. The addition of estradiol to IVM culture medium reversed the effect of miR-378 on cumulus expansion and oocyte meiotic progression, suggesting that decreased estradiol production via suppression of aromatase may be one of the mechanisms by which miR-378 regulates the maturation of COCs. Our data suggest that miR-378 alters gene expression and function in cumulus cells and influences oocyte maturation, possibly via oocyte-cumulus interaction and paracrine regulation.
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Esmaeilian, Yashar, Arzu Atalay, and Esra Erdemli. "Putative germline and pluripotent stem cells in adult mouse ovary and their in vitro differentiation potential into oocyte-like and somatic cells." Zygote 25, no. 3 (June 2017): 358–75. http://dx.doi.org/10.1017/s0967199417000235.
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SummaryAccording to classical knowledge of reproductive biology, in the ovary of female mammals there is a limited number of oocytes and there is no possibility of renewal if the oocytes are lost due to disease or injury. However, in recent years, the results of some studies on renewal and formation of oocytes and follicles in the adult mammalian ovary have led to the questioning of this opinion. The aim of our study is to demonstrate the presence of putative germline and pluripotent stem cells in the adult mouse ovary and their differentiation potential into germ and somatic cells. In ovary tissues and cells harvested from pre-differentiation step, the expression of pluripotent and germline stem cell markers was analysed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and western blotting. Embryoid bodies that formed in this step were analysed using immunofluorescence staining and transmission electron microscopy. Ovarian stem cells were induced to differentiate into oocyte, osteoblast, chondrocyte and neural cells. Besides morphological observation, differentiated cells were analysed by RT-PCR, histochemical and immunofluorescence staining. Expression of germline and pluripotent stem cell markers both in mRNA and at the protein level were detected in the pre-differentiated cells and ovary tissues. As a result of the differentiation process, the formation of oocyte-like cells, osteoblasts, chondrocytes and neural cells was observed and characteristics of differentiated cells were confirmed using the methods mentioned above. Our study results revealed that the adult mouse ovary contains germline and pluripotent stem cells with the capacity to differentiate into oocyte-like cells, osteoblasts, chondrocytes and neural cells.
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Buratini, Jose, Ana Caroline Silva Soares, Rodrigo Garcia Barros, Thaisy Tino Dellaqua, Valentina Lodde, Federica Franciosi, Mariabeatrice Dal Canto, Mario Mignini Renzini, and Alberto Maria Luciano. "Physiological parameters related to oocyte nuclear differentiation for the improvement of IVM/IVF outcomes in women and cattle." Reproduction, Fertility and Development 34, no. 2 (2022): 27. http://dx.doi.org/10.1071/rd21278.
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In vitro maturation (IVM) has been applied in numerous different contexts and strategies in humans and animals, but in both cases it represents a challenge still far from being overcome. Despite the large dataset produced over the last two decades on the mechanisms that govern antral follicular development and oocyte metabolism and differentiation, IVM outcomes are still unsatisfactory. This review specifically focuses on data concerning the potential consequences of using supraphysiological levels of FSH during IVM, as well as on the regulation of oocyte chromatin dynamics and its utility as a potential marker of oocyte developmental competence. Taken together, the data revisited herein indicate that a significant improvement in IVM efficacy may be provided by the integration of pre-OPU patient-specific protocols preparing the oocyte population for IVM and more physiological culture systems mimicking more precisely the follicular environment that would be experienced by the recovered oocytes until completion of metaphase II.
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Machaca, Khaled. "Ca2+ signaling differentiation during oocyte maturation." Journal of Cellular Physiology 213, no. 2 (2007): 331–40. http://dx.doi.org/10.1002/jcp.21194.
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Yang, Cai-Rong, Katie M. Lowther, Maria D. Lalioti, and Emre Seli. "Embryonic Poly(A)-Binding Protein (EPAB) Is Required for Granulosa Cell EGF Signaling and Cumulus Expansion in Female Mice." Endocrinology 157, no. 1 (January 1, 2016): 405–16. http://dx.doi.org/10.1210/en.2015-1135.
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Abstract Embryonic poly(A)-binding protein (EPAB) is the predominant poly(A)-binding protein in Xenopus, mouse, and human oocytes and early embryos before zygotic genome activation. EPAB is required for translational activation of maternally stored mRNAs in the oocyte and Epab−/− female mice are infertile due to impaired oocyte maturation, cumulus expansion, and ovulation. The aim of this study was to characterize the mechanism of follicular somatic cell dysfunction in Epab−/− mice. Using a coculture system of oocytectomized cumulus oophorus complexes (OOXs) with denuded oocytes, we found that when wild-type OOXs were cocultured with Epab−/− oocytes, or when Epab−/− OOXs were cocultured with WT oocytes, cumulus expansion failed to occur in response to epidermal growth factor (EGF). This finding suggests that oocytes and cumulus cells (CCs) from Epab−/− mice fail to send and receive the necessary signals required for cumulus expansion. The abnormalities in Epab−/− CCs are not due to lower expression of the oocyte-derived factors growth differentiation factor 9 or bone morphogenetic protein 15, because Epab−/− oocytes express these proteins at comparable levels with WT. Epab−/− granulosa cells (GCs) exhibit decreased levels of phosphorylated MEK1/2, ERK1/2, and p90 ribosomal S6 kinase in response to lutenizing hormone and EGF treatment, as well as decreased phosphorylation of the EGF receptor. In conclusion, EPAB, which is oocyte specific, is required for the ability of CCs and GCs to become responsive to LH and EGF signaling. These results emphasize the importance of oocyte-somatic communication for GC and CC function.
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PINTO, MARIA ROSARIA, LUIGIA SANTELLA, GIANNA CASAZZA, FLORIANA ROSATI, and ALBERTO MONROY. "The Differentiation of the Vitelline Envelope of Xenopus Oocytes*. (xenopus/oocyte/vitelline envelope/differentiation/fucosyl glycoproteins)." Development, Growth and Differentiation 27, no. 3 (June 1985): 189–200. http://dx.doi.org/10.1111/j.1440-169x.1985.00189.x.
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S., Senarat, Kettratad J., Boonyoung P., Jiraungkoorskul W., Kato F., Mongkolchaichan E., Kaneko G., and Poolprasert P. "Oocyte Differentiation and Reproductive Health of Solitary Tunicate (Styela plicata) from Eastern Coast of Thailand." Sains Malaysiana 50, no. 1 (January 31, 2021): 93–99. http://dx.doi.org/10.17576/jsm-2021-5001-10.
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Histopathological examination is a widely acknowledged technique to assess the reproductive health of aquatic organisms, but it has never been applied to the tunicate Styela plicata, a potential indicator species of water quality. In this study, we examined the oocyte differentiation of S. plicata obtained from the eastern coast of the Gulf of Thailand in order to provide basic information for future assessment of its reproductive health. The mature gonad of S. plicata comprised several ovo-testicular convoluted tubes, in which each tube was divided into apical and terminal portions. The ovarian tissue is located in the apical part of the tunicate body and contained oocytes of various differentiation stages (asynchronous development type) consisting of the four phases namely oogonial proliferation phase, primary growth phase, secondary growth phase (secondary growth and full-growth stages), and post-ovulatory phase. Changes in the morphology of oocytes and follicular cells were described for each differentiation stage. In addition, we unexpectedly observed a high prevalence of atretic follicles (24.5%), which might indicate the oocyte damage by environmental stresses. These findings would be useful for future assessment of reproductive histology of S. plicata and other tunicate species from environmental perspectives.
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Hussein, T. S., R. B. Gilchrist, and J. G. Thompson. "327 OOCYTE-SECRETED FACTORS DIRECTLY AFFECT OOCYTE DEVELOPMENTAL COMPETENCE DURING IN VITRO MATURATION OF THE BOVINE CUMULUS - OOCYTE COMPLEX." Reproduction, Fertility and Development 18, no. 2 (2006): 271. http://dx.doi.org/10.1071/rdv18n2ab327.
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Paracrine factors secreted by the oocyte (oocyte-secreted factors, OSFs) regulate a broad range of cumulus cell functions including proliferation, differentiation, and apoptosis. The capacity of oocytes to regulate their own microenvironment by OSFs may in turn contribute to oocyte developmental competence. The aim of this study was to determine if OSFs have a direct influence on bovine oocyte developmental competence during in vitro maturation (IVM). Cumulus-oocyte complexes (COCs) were obtained by aspiration of >3-mm follicles from abattoir-derived ovaries. IVM was conducted in Bovine VitroMat (Cook Australia, Eight Mile Plains, Brisbane, Australia) supplemented with 0.1 IU/mL rhFSH for 24 h under 6% CO2 in air at 38.5�C. In the first experiment, COCs were co-cultured with denuded oocytes (DOs, 5/COC in 10 �L) beginning at either 0 or 9-h of IVM. To generate the 9-h DO group, COCs were first cultured intact for 9-h and then denuded. In the second experiment, specific OSFs, recombinant bone morphogenetic protein-15 (BMP-15) and growth differentiation factor 9 (GDF-9), were prepared as partially purified supernatants of transfected 293H cells, and used as 10% v/v supplements in Bovine VitroMat. Treatments were: (1) control (no supplement), (2) BMP-15, (3) GDF-9, (4) BMP-15 and GDF-9, and (5) untransfected 293H control. Following maturation, in vitro production of embryos was performed using the Bovine Vitro system (Cook Australia) and blastocysts were examined on Day 8 for development. Developmental data were arcsine-transformed and analyzed by ANOVA, followed by Tukey's test. Cell numbers were analyzed by ANOVA. Co-culturing intact COCs with DOs from 0 or 9 h did not affect cleavage rate, but increased (P < 0.001) the proportion of cleaved embryos that reached the blastocyst stage post-insemination (50.6 � 1.9 and 61.3 � 1.9%, respectively), compared to COCs cultured alone (40.7 � 1.4%). Therefore, paracrine factors secreted by DOs increased the developmental competence of oocytes matured as COCs. OSFs also improved embryo quality, as co-culture of COCs with DOs (0 or 9 h) significantly increased total cell (156.1 � 1.3 and 159.1 � 1.3, respectively) and trophectoderm (105.7 � 1.3 and 109.8 � 0.4, respectively) numbers, compared to control COCs (total = 148 � 1.2, trophectoderm = 98.2 � 0.8, P < 0.001). BMP-15 alone or with GDF-9 also significantly (P < 0.001) increased the proportion of oocytes that reached the blastocyst stage post insemination (57.5 � 2.4% and 55.1 � 4.5%, respectively), compared to control (41.0 � 0.9%) and 293H-treated (27.1 � 3.1%) COCs. GDF-9 also increased blastocyst yield (49.5 � 3.9%) but not significantly. These results are the first to demonstrate that OSFs, and particularly BMP-15 and GDF-9, directly affect bovine oocyte developmental competence. These results have far-reaching implications for improving the efficiency of IVM in domestic species and human infertility treatment, and support the role of OSF production by oocytes as a diagnostic marker for developmental competence.
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Hosoe, M., K. Kaneyama, K. Ushizawa, S. Akagi, J. Noguchi, and T. Takahashi. "233 TEMPOROSPATIAL EXPRESSION PROFILES OF GROWTH AND DIFFERENTIATION FACTOR-9 AND BONE MORPHOGENETIC PROTEIN-15 GENES IN THE BOVINE OVARY." Reproduction, Fertility and Development 18, no. 2 (2006): 225. http://dx.doi.org/10.1071/rdv18n2ab233.
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Bone morphogenetic protein (BMP) family proteins regulate the folliculogenesis and ovulation rate in mammals. Of the members of BMP family, growth and differentiation factor-9 (GDF-9) and BMP-15 are oocyte-derived proteins that play critical roles in follicular development. In the present study, we characterized the temporospatial expression patterns of GDF-9 and BMP-15 in bovine ovaries. Bovine ovaries were obtained from local abattoir. Cumulus–oocyte complexes (COCs) and mural granulosa cells were collected by aspiration of follicles 2–5 mm in diameter. Follicular aspiration was done the day following slaughter. The COC and mural glanulosa cells were separated and cultured for 20 h according to the protocol for oocyte maturation. Total RNA was isolated from COCs, cumulus cells, denuded oocytes, and mural granulosa cells and used for PCR. For in situ hybridization, collected ovaries were immediately fixed with 4% formaldehyde-PBS and embedded in a paraffin block. In situ hybridization was carried out with digoxigenin-labeled probes. In COCs and cumulus cells, the transcripts encoding GDF-9 and BMP-15 were detected immediately after follicular aspiration and still remained at the end of maturation culture. However, in mural granulosa cells, only GDF-9 expression was detected. Germ cell/oocyte markers, ZAR1 and VASA, were not detected in cumulus and mural granulosa cells. Quantitative real-time RT-PCR revealed extensive expressions of both GDF-9 and BMP-15 in oocytes. In situ hybridization study showed that GDF-9 and BMP-15 were co-localized to oocytes in primary, secondary, and antral follicles. The ovular co-expression of GDF-9 and BMP-15 appeared to commence at fetal life. Expression of GDF-9 and BMP-15 was not clear in cumulus cells possibly because of low expression level. In conclusion, our results show that GDF-9 and BMP-15 are co-localized to oocytes from an early stage of folliculogenesis. Since the transcripts encoding GDF-9 and BMP-15 are detected in cumulus cells, it is suggested that the oocyte is not the sole source of them. Additionally, the cumulus and mural granulosa cells are suggested to be functionally differentiated relative to BMP-15 expression.
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Chaffin, Charles L., Keith E. Latham, Namdori R. Mtango, Uros Midic, and Catherine A. VandeVoort. "Dietary Sugar in Healthy Female Primates Perturbs Oocyte Maturation and In Vitro Preimplantation Embryo Development." Endocrinology 155, no. 7 (July 1, 2014): 2688–95. http://dx.doi.org/10.1210/en.2014-1104.
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The consumption of refined sugars continues to pose a significant health risk. However, nearly nothing is known about the effects of sugar intake by healthy women on the oocyte or embryo. Using rhesus monkeys, we show that low-dose sucrose intake over a 6-month period has an impact on the oocyte with subsequent effects on the early embryo. The ability of oocytes to resume meiosis was significantly impaired, although the differentiation of the somatic component of the ovarian follicle into progesterone-producing cells was not altered. Although the small subset of oocytes that did mature were able to be fertilized in vitro and develop into preimplantation blastocysts, there were >1100 changes in blastocyst gene expression. Because sucrose treatment ended before fertilization, the effects of sugar intake by healthy primates are concluded to be epigenetic modifications to the immature oocyte that are manifest in the preimplantation embryo.
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Gilchrist, Robert B. "Recent insights into oocyte - follicle cell interactions provide opportunities for the development of new approaches to in vitro maturation." Reproduction, Fertility and Development 23, no. 1 (2011): 23. http://dx.doi.org/10.1071/rd10225.
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The last 5–10 years of research in ovarian and oocyte biology has delivered some major new advances in knowledge of the molecular and cellular processes regulating oocyte maturation and oocyte developmental competence. These new insights include, among others: (1) the knowledge that oocytes regulate granulosa and cumulus cell differentiation, ovulation rate and fertility via the secretion of soluble paracrine growth factors; (2) new perspectives on the participation of cyclic nucleotides, phosphodiesterases and gap junctions in the regulation of oocyte meiotic arrest and resumption; and (3) the new appreciation of the mechanisms of LH-induced oocyte maturation and ovulation mediated by the follicular cascade of epidermal growth factor (EGF)-like peptides, the EGF receptor and their intracellular second messengers. These recent insights into oocyte–follicle cell interactions provide opportunities for the development of new approaches to oocyte in vitro maturation (IVM). Laboratory IVM methodologies have changed little over the past 20–30 years and IVM remains notably less efficient than hormone-stimulated IVF, limiting its wider application in reproductive medicine and animal breeding. The challenge for oocyte biologists and clinicians practicing IVM is to modernise clinical IVM systems to benefit from these new insights into oocyte–follicle cell interactions in vivo.
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Alton, Michelle, Mau Pan Lau, Michele Villemure, and Teruko Taketo. "The behavior of the X- and Y-chromosomes in the oocyte during meiotic prophase in the B6.YTIR sex-reversed mouse ovary." REPRODUCTION 135, no. 2 (February 2008): 241–52. http://dx.doi.org/10.1530/rep-07-0383.
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Sexual differentiation of the germ cells follows gonadal differentiation, which is determined by the presence or the absence of the Y-chromosome. Consequently, oogenesis and spermatogenesis take place in the germ cells with XX and XY sex chromosomal compositions respectively. It is unclear how sexual dimorphic regulation of meiosis is associated with the sex-chromosomal composition. In the present study, we examined the behavior of the sex chromosomes in the oocytes of the B6.YTIRsex-reversed female mouse, in comparison with XO and XX females. As the sex chromosomes fail to pair in both XY and XO oocytes during meiotic prophase, we anticipated that the pairing failure may lead to excessive oocyte loss. However, the total number of germ cells, identified by immunolabeling of germ cell nuclear antigen 1 (GCNA1), did not differ between XY and XX ovaries or XO and XX ovaries up to the day of delivery. The progression of meiotic prophase, assessed by immunolabeling of synaptonemal complex components, was also similar between the two genotypes of ovaries. These observations suggest that the failure in sex-chromosome pairing is not sufficient to cause oocyte loss. On the other hand, labeling of phosphorylated histone γH2AX, known to be associated with asynapsis and transcriptional repression, was seen over the X-chromosome but not over the Y-chromosome in the majority of XY oocytes at the pachytene stage. For comparison, γH2AX labeling was seen only in the minority of XX oocytes at the same stage. We speculate that the transcriptional activity of sex chromosomes in the XY oocyte may be incompatible with ooplasmic maturation.
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Gilchrist, R. B., L. J. Ritter, S. Myllymaa, N. Kaivo-Oja, F. Amato, O. Ritvos, and D. G. Mottershead. "247.Molecular basis of oocyte - paracrine signalling that promotes mouse granulosa cell proliferation." Reproduction, Fertility and Development 16, no. 9 (2004): 247. http://dx.doi.org/10.1071/srb04abs247.
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Oocytes regulate follicle growth and development by secreting paracrine growth factors that act on granulosa cells (GC). We have recently determined that growth differentiation factor-9 (GDF-9) accounts for ~50% of the total mitogenic activity of oocytes, the remaining portion is as yet uncharacterised. This study was conducted to identify the receptor/signalling system utilised by oocytes to promote GC proliferation. We used an established oocyte-secreted mitogen bioassay, where denuded oocytes are co-cultured with primed-mouse mural GC. In this system, oocytes, GDF-9, TGF-b1 and activin-A all promoted GC DNA synthesis in a dose-dependent manner, but bone-morphogenetic protein-6 (BMP-6) and BMP-7 did not. The type-II receptor for GDF-9 is BMPRII and using real-time RT-PCR, cumulus cells (CC) and mural GC were found to express equivalent levels of BMPRII mRNA. We tested the capacity of the receptor ectodomain (ECD) to neutralise oocyte-stimulated mural GC proliferation. The BMPRII ECD antagonised both oocyte and GDF-9 bioactivity in a dose-dependent manner, completely abolishing activity of both mitogens at 1 ug/mL. The BMPRII ECD did not antagonise TGF-β and partially antagonised activin-A bioactivity, demonstrating its specificity. The TGFβR-II ECD, activin R-II ECD and activin R-IIB ECD all failed to neutralise oocyte- or GDF-9-stimulated GC DNA synthesis, whereas they did antagonise the activity of their respective ligands. The BMPRII ECD also completely antagonised oocyte-stimulated CC DNA synthesis. Using this oocyte-factor bioassay with mural GC transfected with Smad luciferase reporter constructs, we found that oocytes, GDF-9 and TGF-β (but not BMP-6) activated the Smad2/3 pathway. Consistent with this, oocytes and GDF-9 led to phosphorylation of GC Smad2 molecules as detected by Western blot. Conversely the Smad1/5/8 pathway was activated by BMP-6, but not by GDF-9, TGF-β nor surprisingly by oocytes. This study provides evidence that BMPRII is a key receptor for transmitting the paracrine actions of oocytes in GC. However, oocyte-secreted factors do not activate the BMP intracellular signalling pathway but rather the TGF-β/activin intracellular pathway.
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Lodde, Valentina, Rodrigo Garcia Barros, Priscila Chediek Dall’Acqua, Cecilia Dieci, Claude Robert, Alexandre Bastien, Marc-André Sirard, Federica Franciosi, and Alberto Maria Luciano. "Zinc supports transcription and improves meiotic competence of growing bovine oocytes." Reproduction 159, no. 6 (May 2020): 679–91. http://dx.doi.org/10.1530/rep-19-0398.
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In the last years, many studies focused on the understanding of the possible role of zinc in the control of mammalian oogenesis, mainly on oocyte maturation and fertilization. However, little is known about the role of zinc at earlier stages, when the growing oocyte is actively transcribing molecules that will regulate and sustain subsequent stages of oocyte and embryonic development. In this study, we used the bovine model to gain insights into the possible involvement of zinc in oocyte development. We first mined the EmbryoGENE transcriptomic dataset, which revealed that several zinc transporters and methallothionein are impacted by physiological conditions throughout the final phase of oocyte growth and differentiation. We then observed that zinc supplementation during in vitro culture of growing oocytes is beneficial to the acquisition of meiotic competence when subsequently subjected to standard in vitro maturation. Furthermore, we tested the hypothesis that zinc supplementation might support transcription in growing oocytes. This hypothesis was indirectly confirmed by the experimental evidence that the content of labile zinc in the oocyte decreases when a major drop in transcription occurs in vivo. Accordingly, we observed that zinc sequestration with a zinc chelator rapidly reduced global transcription in growing oocytes, which was reversed by zinc supplementation in the culture medium. Finally, zinc supplementation impacted the chromatin state by reducing the level of global DNA methylation, which is consistent with the increased transcription. In conclusion, our study suggests that altering zinc availability by culture-medium supplementation supports global transcription, ultimately enhancing meiotic competence.
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Kim, Bo Hyun, Won Seok Ju, Ji-Su Kim, Sun-Uk Kim, Soon Ju Park, Sean M. Ward, Ju Hyeong Lyu, and Young-Kug Choo. "Effects of Gangliosides on Spermatozoa, Oocytes, and Preimplantation Embryos." International Journal of Molecular Sciences 21, no. 1 (December 22, 2019): 106. http://dx.doi.org/10.3390/ijms21010106.
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Gangliosides are sialic acid-containing glycosphingolipids, which are the most abundant family of glycolipids in eukaryotes. Gangliosides have been suggested to be important lipid molecules required for the control of cellular procedures, such as cell differentiation, proliferation, and signaling. GD1a is expressed in interstitial cells during ovarian maturation in mice and exogenous GD1a is important to oocyte maturation, monospermic fertilization, and embryonic development. In this context, GM1 is known to influence signaling pathways in cells and is important in sperm–oocyte interactions and sperm maturation processes, such as capacitation. GM3 is expressed in the vertebrate oocyte cytoplasm, and exogenously added GM3 induces apoptosis and DNA injury during in vitro oocyte maturation and embryogenesis. As a consequence of this, ganglioside GT1b and GM1 decrease DNA fragmentation and act as H2O2 inhibitors on germ cells and preimplantation embryos. This review describes the functional roles of gangliosides in spermatozoa, oocytes, and early embryonic development.
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Andreuccetti, P., C. M. Motta, and S. Filosa. "Regulation of oocyte number during oocyte differentiation in the lizard Podarcis sicula." Cell Differentiation and Development 29, no. 2 (February 1990): 129–41. http://dx.doi.org/10.1016/0922-3371(90)90066-6.
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Lacham-Kaplan, O. "PS-1.1 Oocyte differentiation from stem cells." Reproductive BioMedicine Online 16 (January 2008): S—3—S—4. http://dx.doi.org/10.1016/s1472-6483(10)61469-1.
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Theurkauf, William E. "Oocyte differentiation: A motor makes a difference." Current Biology 7, no. 9 (September 1997): R548—R551. http://dx.doi.org/10.1016/s0960-9822(06)00278-8.
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El-Jouni, Wassim, Byungwoo Jang, Shirley Haun, and Khaled Machaca. "Calcium signaling differentiation during Xenopus oocyte maturation." Developmental Biology 288, no. 2 (December 2005): 514–25. http://dx.doi.org/10.1016/j.ydbio.2005.10.034.
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Ullah, Ghanim, Peter Jung, and Khaled Machaca. "Modeling Ca2+ signaling differentiation during oocyte maturation." Cell Calcium 42, no. 6 (December 2007): 556–64. http://dx.doi.org/10.1016/j.ceca.2007.01.010.
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Cecconi, Sandra, Gianna Rossi, and Maria Grazia Palmerini. "Mouse oocyte differentiation during antral follicle development." Microscopy Research and Technique 69, no. 6 (2006): 408–14. http://dx.doi.org/10.1002/jemt.20300.
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Bezerra, Francisco Taiã G., Laís R. F. M. Paulino, Bianca R. Silva, Anderson W. B. Silva, Ana L. P. Souza Batista, and José R. V. Silva. "Effects of epidermal growth factor and progesterone on oocyte meiotic resumption and the expression of maturation-related transcripts during prematuration of oocytes from small and medium-sized bovine antral follicles." Reproduction, Fertility and Development 32, no. 14 (2020): 1190. http://dx.doi.org/10.1071/rd20099.
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This study evaluated the effects of epidermal growth factor (EGF) and progesterone (P4) on growth, the resumption of meiosis and expression of eukaryotic translation initiation factor 4E(eIF4E), poly(A)-specific ribonuclease (PARN), oocyte-specific histone H1 (H1FOO), oocyte maturation factor Mos (cMOS), growth differentiation factor-9 (GDF9) and cyclin B1 (CCNB1) mRNA in oocytes from small and medium-sized antral follicles after prematuration and maturation invitro. Oocytes from small (<2.0mm) and medium (3.0–6.0mm) antral follicles were cultured in medium containing EGF (10ng mL–1), P4 (100 µM) or both. After culture, growth rate, resumption of meiosis and eIF4E, PARN, H1FOO, cMOS, GDF9 and CCNB1 mRNA levels were evaluated. P4 increased cMOS, H1FOO and CCNB1 mRNA levels after the culture of oocytes from small antral follicles, and EGF increased CCNB1 mRNA levels in these oocytes. In the medium-sized antral follicles, P4 alone or in combination with EGF increased oocyte diameter after prematuration invitro. In these oocytes, the presence of either EGF or P4 in the culture medium increased cMOS mRNA levels. In conclusion, P4 increases cMOS, H1FOO and CCNB1 mRNA levels after the culture of oocytes from small antral follicles. P4 and the combination of EGF and P4 promote the growth of oocytes from medium-sized antral follicles, and both EGF and P4 increase cMOS mRNA levels.
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Brązert, Maciej, Wiesława Kranc, Karol Jopek, Bartosz Kempisty, and Leszek Pawelczyk. "New markers of human cumulus oophorus cells cultured in vitro – transcriptomic profile." Medical Journal of Cell Biology 8, no. 1 (April 29, 2020): 60–72. http://dx.doi.org/10.2478/acb-2020-0007.
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AbstractThe presence of CCs around the oocyte after ovulation is one of the key elements contributing to oocyte developmental competence. In the presented study, we used CCs from 12 patients aged 18-40 diagnosed with infertility. After harvesting cells on day 1, 7, 15 and 30 of culture, total RNA was isolated and transcriptomic analysis was performed. The DAVID software indicated the following GO BP terms: “cell junction organization”, “cell migration”, “cell morphogenesis involved in differentiation”, “cell morphogenesis” and “cell motility”. Of the genes belonging to all ontological groups, the most downregulated were: SLC7A8, DFNB31, COL1A1, CDC42SE1, TGFBR3, HMGB1, with the most upregulated genes being: ANXA3, KIAA1199, HTR2B, VCAM1, DKK1.While many studies focus on attempts to obtain fully competent oocytes, scientists still have difficulty attaining adequate results in vitro. Lack of adequate knowledge often results in low in vitro fertilization efficiency. Therefore, our research focuses on CCs cells, thanks to which the oocyte most likely acquires developmental competence. The main purpose of the study was to identify the potential molecular markers responsible for cell junction organization, migration, differentiation, morphogenesis and motility.Running title: New markers of human cumulus oophorus cells cultured in vitro
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Richani, Dulama, Kylie R. Dunning, Jeremy G. Thompson, and Robert B. Gilchrist. "Metabolic co-dependence of the oocyte and cumulus cells: essential role in determining oocyte developmental competence." Human Reproduction Update 27, no. 1 (October 6, 2020): 27–47. http://dx.doi.org/10.1093/humupd/dmaa043.
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Abstract BACKGROUND Within the antral follicle, the oocyte is reliant on metabolic support from its surrounding somatic cells. Metabolism plays a critical role in oocyte developmental competence (oocyte quality). In the last decade, there has been significant progress in understanding the metabolism of the cumulus–oocyte complex (COC) during its final stages of growth and maturation in the follicle. Certain metabolic conditions (e.g. obesity) or ART (e.g. IVM) perturb COC metabolism, providing insights into metabolic regulation of oocyte quality. OBJECTIVE AND RATIONALE This review provides an update on the progress made in our understanding of COC metabolism, and the metabolic conditions that influence both meiotic and developmental competence of the oocyte. SEARCH METHODS The PubMed database was used to search for peer-reviewed original and review articles. Searches were performed adopting the main terms ‘oocyte metabolism’, ‘cumulus cell metabolism’, ‘oocyte maturation’, ‘oocyte mitochondria’, ‘oocyte metabolism’, ‘oocyte developmental competence’ and ‘oocyte IVM’. OUTCOMES Metabolism is a major determinant of oocyte quality. Glucose is an essential requirement for both meiotic and cytoplasmic maturation of the COC. Glucose is the driver of cumulus cell metabolism and is essential for energy production, extracellular matrix formation and supply of pyruvate to the oocyte for ATP production. Mitochondria are the primary source of ATP production within the oocyte. Recent advances in real-time live cell imaging reveal dynamic fluctuations in ATP demand throughout oocyte maturation. Cumulus cells have been shown to play a central role in maintaining adequate oocyte ATP levels by providing metabolic support through gap junctional communication. New insights have highlighted the importance of oocyte lipid metabolism for oocyte oxidative phosphorylation for ATP production, meiotic progression and developmental competence. Within the last decade, several new strategies for improving the developmental competence of oocytes undergoing IVM have emerged, including modulation of cyclic nucleotides, the addition of precursors for the antioxidant glutathione or endogenous maturation mediators such as epidermal growth factor-like peptides and growth differentiation factor 9/bone morphogenetic protein 15. These IVM additives positively alter COC metabolic endpoints commonly associated with oocyte competence. There remain significant challenges in the study of COC metabolism. Owing to the paucity in non-invasive or in situ techniques to assess metabolism, most work to date has used in vitro or ex vivo models. Additionally, the difficulty of measuring oocyte and cumulus cell metabolism separately while still in a complex has led to the frequent use of denuded oocytes, the results from which should be interpreted with caution since the oocyte and cumulus cell compartments are metabolically interdependent, and oocytes do not naturally exist in a naked state until after fertilization. There are emerging tools, including live fluorescence imaging and photonics probes, which may provide ways to measure the dynamic nature of metabolism in a single oocyte, potentially while in situ. WIDER IMPLICATIONS There is an association between oocyte metabolism and oocyte developmental competence. Advancing our understanding of basic cellular and biochemical mechanisms regulating oocyte metabolism may identify new avenues to augment oocyte quality and assess developmental potential in assisted reproduction.
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Gupta, Swati, Sriti Pandey, Mehtab S. Parmar, Anjali Somal, Avishek Paul, Bibhudatta S. K. Panda, Irfan A. Bhat, et al. "Impact of oocyte-secreted factors on its developmental competence in buffalo." Zygote 25, no. 3 (June 2017): 313–20. http://dx.doi.org/10.1017/s0967199417000156.
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SummaryOocyte-secreted factors (OSFs) play an important role in the acquisition of oocyte developmental competence through bidirectional cross-talk between oocyte and cumulus cells via gap junctions. Thus, the present study was designed to investigate the effect of two OSFs, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), on the developmental competence of buffalo oocytes derived from two different follicle sizes. Cumulus–oocyte complexes (COCs) from large follicles (LF, >6 mm) or small follicles (SF, <6 mm) were collected and matured in vitro either in the presence of GDF9 or BMP15, or both, or with the denuded oocytes (DOs) as a source of native OSFs. Cleavage and blastocyst rates were significantly (P < 0.05) higher in LF-derived than SF-derived oocytes. Cleavage and blastocyst rates were significantly higher (P < 0.05) in the DOs and the combination groups compared with the control, GDF9 alone and BMP15 alone groups, both in LF-derived and SF-derived oocytes, although the cleavage and blastocyst rates did not differ significantly (P > 0.05) between DOs and combination groups. Relative mRNA analysis revealed significantly higher (P > 0.05) expression of the cumulus cell marker genes EGFR, HAS2, and CD44 in LF-derived than SF-derived oocyte; the expression of these markers was significantly higher (P > 0.05) in DOs and combination groups, irrespective of the follicle size. These results suggested that LF-derived oocytes have a higher developmental competence than SF-derived oocytes and that supplementation of GDF9 and BMP15 modulates the developmental competence of buffalo oocytes by increasing the relative abundance of cumulus-enabling factors and thereby increasing cleavage and the quality of blastocyst production.
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Su, You-Qiang, Koji Sugiura, Qinglei Li, Karen Wigglesworth, Martin M. Matzuk, and John J. Eppig. "Mouse Oocytes Enable LH-Induced Maturation of the Cumulus-Oocyte Complex via Promoting EGF Receptor-Dependent Signaling." Molecular Endocrinology 24, no. 6 (June 1, 2010): 1230–39. http://dx.doi.org/10.1210/me.2009-0497.
Full textAbstract:
Abstract LH triggers the maturation of the cumulus-oocyte complex (COC), which is followed by ovulation. These ovarian follicular responses to LH are mediated by epidermal growth factor (EGF)-like growth factors produced by granulosa cells and require the participation of oocyte-derived paracrine factors. However, it is not clear how oocytes coordinate with the EGF receptor (EGFR) signaling to achieve COC maturation. The aim of the present study was to test the hypothesis that oocytes promote the expression of EGFR by cumulus cells, thus enabling them to respond to the LH-induced EGF-like peptides. Egfr mRNA and protein expression were dramatically reduced in cumulus cells of mutant mice deficient in the production of the oocyte-derived paracrine factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15). Moreover, microsurgical removal of oocytes from wild-type COCs dramatically reduced expression of Egfr mRNA and protein, and these levels were restored by either coculture with oocytes or treatment with recombinant GDF9 or GDF9 plus recombinant BMP15. Blocking Sma- and Mad-related protein (SMAD)2/3 phosphorylation in vitro inhibited Egfr expression in wild-type COCs and in GDF9-treated wild-type cumulus cells, and conditional deletion of Smad2 and Smad3 genes in granulosa cells in vivo resulted in the reduction of Egfr mRNA in cumulus cells. These results indicate that oocytes promote expression of Egfr in cumulus cells, and a SMAD2/3-dependent pathway is involved in this process. At least two oocyte-derived growth factors, GDF9 and BMP15, are required for EGFR expression by cumulus cells.
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Hussein, Tamer S., Melanie L. Sutton-McDowall, Robert B. Gilchrist, and Jeremy G. Thompson. "Temporal effects of exogenous oocyte-secreted factors on bovine oocyte developmental competence during IVM." Reproduction, Fertility and Development 23, no. 4 (2011): 576. http://dx.doi.org/10.1071/rd10323.
Full textAbstract:
We investigated whether paracrine signalling between the bovine oocyte and cumulus cells is altered during the course of in vitro maturation (IVM). Bovine COCs were cocultured with denuded oocytes or treated with specific oocyte-secreted factors, namely recombinant bone morphogenetic protein (BMP)-15 or growth differentiation factor (GDF)-9, beginning from 0 or 9 h IVM. To generate a 9-h denuded oocyte (DO) group, COCs were cultured intact for the first 9 h of IVM and then denuded. Coculturing intact COCs with DOs denuded immediately after collection or following 9 h of maturation did not affect cleavage rate, but improved blastocyst yield (P < 0.05) on Day 8 (51 and 61%, respectively; P < 0.05) and cell number compared with COCs cultured alone (41%). Significantly, we observed higher levels of endogenous GDF-9 and BMP-15 protein in oocytes of COCs matured for 9 h compared with no incubation. The addition of 175 ng mL–1 GDF-9 or 10% v/v BMP-15 from partially purified transfected 293H cell supernatant for 24 h IVM significantly enhanced development to the blastocyst stage from 40% (control) to 51 and 47%, respectively (P < 0.05). However, treatment of COCs with GDF-9 or BMP-15 between 9 and 24 h of IVM did not increase blastocyst yield. These results provide evidence of quantitative and possibly qualitative temporal changes in oocyte paracrine factor production during IVM.
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Kere, Michel, Pan-Chen Liu, Yuh-Kun Chen, Pei-Chi Chao, Li-Kuang Tsai, Ting-Yu Yeh, Chawalit Siriboon, et al. "Ultrastructural Characterization of Porcine Growing and In Vitro Matured Oocytes." Animals 10, no. 4 (April 11, 2020): 664. http://dx.doi.org/10.3390/ani10040664.
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This study aimed to investigate ultrastructural changes of growing porcine oocytes and in vitro maturated oocytes. Light microscopy was used to characterize and localize the primordial, primary, secondary, and tertiary follicles. During oocyte growth and maturation, the morphology of mitochondria was roundish or ovoid in shape depending on the differentiation state, whereas their mean diameters oscillated between 0.5 and 0.7 µm, respectively, from primary and secondary follicles. Hooded mitochondria were found in the growing oocytes of the tertiary follicles. In addition to the pleomorphism of mitochondria, changes in the appearance of lipid droplets were also observed, along with the alignment of a single layer of cortical granules beneath the oolemma. In conclusion, our study is apparently the first report to portray morphological alterations of mitochondria that possess the hooded structure during the growth phase of porcine oocytes. The spatiotemporal and intrinsic changes during oogenesis/folliculogenesis are phenomena at the ultrastructural or subcellular level of porcine oocytes, highlighting an in-depth understanding of oocyte biology and impetus for future studies on practical mitochondrion replacement therapies for oocytes.
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Skinner, S. M., and B. S. Dunbar. "Localization of a carbohydrate antigen associated with growing oocytes and ovarian surface epithelium." Journal of Histochemistry & Cytochemistry 40, no. 7 (July 1992): 1031–36. http://dx.doi.org/10.1177/40.7.1607636.
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We used a monoclonal antibody (PS1) to a carbohydrate antigen to study the development of the oocyte and follicle during early stages of differentiation in several mammalian species. This antigen has been shown to localize within the cytoplasm of oocytes in primordial follicles as well as in growing oocytes. It is also localized within distinct layers of the zona pellucida (ZP) of developing follicles. Although this antibody was made against a specific ZP glycoprotein, the antigen also appears to be abundant in cells of the ovarian surface epithelium (OSE). The localization of this carbohydrate moiety has been observed in ovaries of rabbits of different ages as well as in the ovarian surface epithelium of other mammalian species including cat, cynomolgus monkey, baboon, and human. These studies demonstrate that there is an abundant carbohydrate antigenic determinant which is associated with both the mammalian oocyte and the ovarian surface epithelium but which is not apparent in other ovarian cell types or in non-ovarian secretory epithelium. This antibody probe should provide a valuable tool for studying the development and differentiation of the ovary, since this antigen is associated with two highly differentiated but distinct cell types.
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Hosoe, M., K. Ushizawa, K. G. Hayashi, and T. Takahashi. "187 DIFFERENTIAL EXPRESSIONS OF GROWTH AND DIFFERENTIATION FACTOR 9 AND BONE MORPHOGENETIC PROTEIN 15 GENES IN OVARIES OF THE CALF AND COW." Reproduction, Fertility and Development 23, no. 1 (2011): 195. http://dx.doi.org/10.1071/rdv23n1ab187.
Full textAbstract:
It has been reported that prepubertal calf oocytes are less developmentally competent than those obtained from cows. The bone morphogenetic protein (BMP) family of proteins regulate folliculogenesis and the ovulation rate in mammals. Of the members of the BMP family, growth and differentiation factor 9 (GDF9) and BMP15 are oocyte-derived proteins that play critical roles in granulosa cell proliferation and differentiation. In the present study, we characterised the gene expression of bovine GDF9 and BMP15 in calf and adult cow ovaries. The ovaries obtained from 4 calves at 9 to 11 months old and 4 cows at 4 to 6 years old. For quantitative real-time RT-PCR (qPCR), cumulus–oocyte complexes (COC) and mural granulosa cells were collected by aspiration of follicles 2 to 5 mm in diameter from an ovary from each animal. Ovaries from the other side were used for in situ hybridization. The COC and mural granulosa cells were separated and cultured for 22 h according to the protocol for oocyte maturation. Total RNA was isolated from denuded oocytes, cumulus cells, and mural granulosa cells. Bovine glyceraldehyde-3-phosphate dehydrogenase was used to normalise qPCR efficiency. For in situ hybridization, the collected ovaries were immediately fixed with 4% formaldehyde-PBS and embedded in a paraffin block. In situ hybridization was carried out with digoxigenin-labelled RNA probes. We confirmed there was no contamination of oocytes in the collected cumulus and mural granulosa cells by determining the mRNA expression of germ cell–oocyte markers (ZAR1 and VASA). Two, 16, 7, and 10 COC were collected from the ovary on one side of each calf, and 14, 22, 29, and 33 COC were collected from an ovary of each adult cow. Two COC from the calves could not be used for qPCR analysis. Both GDF9 and BMP15 mRNA were detected in oocytes and cumulus cells at the end of maturation culture, whereas only GDF9 mRNA was detected in mural granulosa cells. Quantitative PCR detection revealed that BMP15 and GDF9 mRNA expression of the cumulus cells from adult ovaries was significantly greater than that from calf ovaries. The expression of GDF9 mRNA was significantly greater in calf oocytes than in oocytes from cows. However, BMP15 mRNA expression in the oocytes of calf and adult ovaries was not significantly different. In mural granulosa cells, the intensities of GDF9 mRNA expression were not significantly different between calves and cows. These qPCR results were also ascertained by in situ hybridization. In conclusion, we clarified that the characteristics of bovine GDF9 and BMP15 mRNA expression in oocytes and cumulus cells were different between calves and cows. Our results indicate the possibility that the calf oocytes were less developmentally competent because of excess GDF9 on the oocytes, deficiencies of GDF9 and BMP15 on the cumulus cells, or both.
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Styhler, S., A. Nakamura, A. Swan, B. Suter, and P. Lasko. "vasa is required for GURKEN accumulation in the oocyte, and is involved in oocyte differentiation and germline cyst development." Development 125, no. 9 (May 1, 1998): 1569–78. http://dx.doi.org/10.1242/dev.125.9.1569.
Full textAbstract:
The Drosophila gene vasa is required for pole plasm assembly and function, and also for completion of oogenesis. To investigate the role of vasa in oocyte development, we generated a new null mutation of vasa, which deletes the entire coding region. Analysis of vasa-null ovaries revealed that the gene is involved in the growth of germline cysts. In vasa-null ovaries, germaria are atrophied, and contain far fewer developing cysts than do wild-type germaria; a phenotype similar to, but less severe than, that of a null nanos allele. The null mutant also revealed roles for vasa in oocyte differentiation, anterior-posterior egg chamber patterning, and dorsal-ventral follicle patterning, in addition to its better-characterized functions in posterior embryonic patterning and pole cell specification. The anterior-posterior and dorsal-ventral patterning phenotypes resemble those observed in gurken mutants. vasa-null oocytes fail to efficiently accumulate many localized RNAs, such as Bicaudal-D, orb, oskar, and nanos, but still accumulate gurken RNA. However, GRK accumulation in the oocyte is severely reduced in the absence of vasa function, suggesting a function for VASA in activating gurken translation in wild-type ovaries.
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Gilchrist, R. B. "065. THE MAMMALIAN OOCYTE: FROM BENCH TO CLINIC." Reproduction, Fertility and Development 21, no. 9 (2009): 18. http://dx.doi.org/10.1071/srb09abs065.
Full textAbstract:
The mature mammalian oocyte is the central link between generations. It is not only responsible for the transfer of the female genome between generations, but also largely determines embryo and early fetal developmental potential. For any female, oocytes are in limited supply and are easily damaged, such that the availability of high quality or developmentally competent oocytes is a fundamental rate-limiting factor in female fertility. This is particularly relevant in Australian society today with the steadily rising age to first conception which adversely affects oocyte quality and female fertility. Yet despite years of research and clinical IVF we still have a poor understanding of the molecular and cellular processes that control oocyte quality. It is clear that oocytes acquire developmental competence in the ovarian follicle. The acquisition of competence necessitates communication between the oocyte and maternal systems, a process which endows developmental potential as the oocyte grows and matures inside the follicle. At the cellular level this is achieved by bi-directional communication between oocytes and their companion somatic cells [1]. Over the past 10 years my laboratory has focused heavily on the nature of these oocyte-somatic communication axes and their impact on oocyte quality. Over this period, our work and that of others has shaped a new paradigm in ovarian biology, which is that the oocyte is not passive in the follicle, but rather that it actively directs the differentiation of its neighbouring somatic cells into cumulus cells through the secretion of GDF9 and BMP15 growth factors [2]. In doing so, oocytes dictate the function of their neighboring cumulus cells, directing them to perform functions needed for the appropriate growth and development of the oocyte. For example, cumulus cells supply oocytes with an array of nutrients, substrates and regulatory molecules such as cAMP, many directly through gap-junctions. These communication axes establish and maintain an elaborate and intricate local oocyte-cumulus auto regulatory loop that is required to enable post-fertilisation development. A clear clinical application of this new knowledge is in Artificial Reproductive Technologies, in particular oocyte in vitro maturation (IVM) [3]. IVM biotechnologies have the capacity to capture the vast supply of oocytes in the mammalian ovary and generate mature oocytes in vitro. Generating offspring using IVM is already a clinically and commercially viable biotechnology in livestock breeding programs, particularly in cattle. IVM is a particularly attractive technology for the treatment of human infertility, as it removes the need for expensive and potentially harmful ovarian hyperstimulation protocols used in clinical IVF. However, widespread application of IVM in humans requires an increase in efficiency and further examination of safety of the technology. Recent work from my laboratory has increased IVM success rates in animals by using GDF9 and BMP15 in IVM [2, 3] and by developing a new system of “Induced-IVM” that more closely resembles the mechanisms of oocyte maturation in vivo. Most recently, the latter approach has led to substantial increases in embryo yield and pregnancy outcomes to levels equivalent to hormone-stimulated IVF [4]. The next challenge is to adapt these new approaches to clinical/field conditions to provide new opportunities for infertile women and for the development of a wide range of reproductive biotechnologies.
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McGrail, M., and T. S. Hays. "The microtubule motor cytoplasmic dynein is required for spindle orientation during germline cell divisions and oocyte differentiation in Drosophila." Development 124, no. 12 (June 15, 1997): 2409–19. http://dx.doi.org/10.1242/dev.124.12.2409.
Full textAbstract:
During animal development cellular differentiation is often preceded by an asymmetric cell division whose polarity is determined by the orientation of the mitotic spindle. In the fruit fly, Drosophila melanogaster, the oocyte differentiates in a 16-cell syncytium that arises from a cystoblast which undergoes 4 synchronous divisions with incomplete cytokinesis. During these divisions, spindle orientation is highly ordered and is thought to impart a polarity to the cyst that is necessary for the subsequent differentiation of the oocyte. Using mutations in the Drosophila cytoplasmic dynein heavy chain gene, Dhc64C, we show that cytoplasmic dynein is required at two stages of oogenesis. Early in oogenesis, dynein mutations disrupt spindle orientation in dividing cysts and block oocyte determination. The localization of dynein in mitotic cysts suggests spindle orientation is mediated by the microtubule motor cytoplasmic dynein. Later in oogenesis, dynein function is necessary for proper differentiation, but does not appear to participate in morphogen localization within the oocyte. These results provide evidence for a novel developmental role for the cytoplasmic dynein motor in cellular determination and differentiation.
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Yeo, C. X., R. B. Gilchrist, and M. Lane. "224. Disruption of bi-directional oocyte-cumulus paracrine signalling during oocyte in vitro maturation reduces subsequent mouse fetal survival." Reproduction, Fertility and Development 20, no. 9 (2008): 24. http://dx.doi.org/10.1071/srb08abs224.
Full textAbstract:
During folliculogenesis, oocyte to cumulus cell (CC) bi-directional communication is essential for normal development of the oocyte. We recently showed that addition of recombinant oocyte paracrine factor growth differentiation factor 9 (GDF9) during mouse oocyte in vitro maturation (IVM) increased fetal viability. GD.F. 9 signals through SMAD 2/3. Hence the effects of disrupting SMAD2/3 signalling and its interaction with FSH/EGF during IVM on oocyte development and subsequent fetal outcomes were investigated. Cumulus-oocyte complexes (COCs) from antral follicles (n = 400–500) of eCG treated pre-pubertal (C57BL/6xCBA F1 hybrid) mice were cultured for 18 h in Waymouth's medium+5% serum, with or without 50 mIU/mL FSH and 10ng/mL EGF, SMAD2/3 inhibitor SB-431542 (4µM), or its 0.04% DMSO control. Meiotic maturation was assessed by first polar body (PB1) extrusion immediately after culture. COCs were fertilised and cultured to the blastocyst stage in G1.2/G2.2 media at 37°C in 6%CO2:5%O2:89%N2. Blastocysts were either transferred to pseudo-pregnant Swiss females or differentially stained. Pregnancy outcome was assessed on Day 18 of pregnancy. Inhibition of SMAD 2/3 signalling did not alter meiotic maturation. No differences were observed in the percentage of blastocysts or hatching blastocysts from cleaved embryos with SMAD2/3 inhibition or the absence of FSH/EGF. However, IVM with SB-431542 or without FSH/EGF significantly decreased (P < 0.001) blastocyst inner cell mass percentages (26% v. 35% control;18% v. 28% control respectively). Fetal survival (fetuses per embryo transferred) of oocytes matured with SB-431542 was significantly decreased (30% v. 50% controls; P < 0.05) although implantation rates and subsequent fetal weights were unaffected. These findings demonstrate the importance of oocyte-CC communication throughout IVM. Inhibition of oocyte signalling through SMAD2/3 resulted in reduced blastocyst quality and fetal survival; outcomes similar to that of oocytes matured without FSH/EGF. Oocyte–cumulus cell bi-directional communication is thus an important feature of oocyte viability and has a substantial impact on subsequent fetal outcomes.
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Gilchrist, Robert B., and Lesley J. Ritter. "Differences in the participation of TGFB superfamily signalling pathways mediating porcine and murine cumulus cell expansion." REPRODUCTION 142, no. 5 (November 2011): 647–57. http://dx.doi.org/10.1530/rep-11-0196.
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It is widely held that mammalian cumulus cell (CC) expansion requires oocyte-paracrine signalling, however in three of the four species studied to date, CC expansion occurs in the absence of the oocyte. This study was conducted to examine the paracrine and SMAD/MAPK intracellular signalling mechanism mediating porcine CC expansion, and to compare these to the mouse. Cumulus–oocyte complexes (COCs) and oocyte-free complexes (OOXs) from pigs and eCG-primed mice were treated in vitro with FSH and a broad range of TGFB superfamily antagonists. Expansion of porcine COCs and OOXs was unaffected by neutralisation of growth differentiation factor 9, TGFB, activin A, activin B and a broad spectrum bone morphogenetic protein antagonist. A SMAD-responsive luciferase reporter assay confirmed that porcine oocytes secreted factors that activate SMAD3 and SMAD1/5/8 in granulosa cells, but murine oocytes activated SMAD3 only. Treatment of COCs with a SMAD2/3 phosphorylation inhibitor (SB431542) partially inhibited porcine CC expansion and expression of TNFAIP6, but ablated murine CC expansion. SB431542 was equally effective at attenuating porcine CC expansion in the presence or absence of the oocyte. By contrast, a SMAD1/5/8 phosphorylation inhibitor (dorsomorphin) had no effect on porcine or murine CC function. Inhibition of ERK1/2 and p38 MAPK signalling pathways prevented porcine COC expansion and expression of most matrix genes examined. The activation of CC SMAD signalling by oocytes, and the requirement of SMAD2/3 signalling for expansion, is notably contrasted in pigs and mice. Nonetheless, porcine CC SMAD2/3 signalling is likely to be needed for optimal matrix formation, possibly by facilitating essential MAPK signals.