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Статті в журналах з теми "Cumulus oocyte complex (COC)"
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Lisle, R. S., K. Anthony, M. A. Randall, and F. J. Diaz. "Oocyte–cumulus cell interactions regulate free intracellular zinc in mouse oocytes." REPRODUCTION 145, no. 4 (April 2013): 381–90. http://dx.doi.org/10.1530/rep-12-0338.
Повний текст джерелаАнотація:
Zinc increases in the oocyte during maturation and is required for progression and completion of meiosis. The objective of this study was to determine whether cumulus cells regulate the levels of free intracellular zinc in the oocyte during maturation. In the cumulus–oocyte complex (COC) the relative level of free intracellular zinc was almost fourfold higher in cumulus cells compared with the resident germinal vesicle-stage oocyte. Removal of cumulus cells caused a fourfold increase in intracellular zinc in the oocyte by 1 h after cumulus cell removal, but subsequent coculture of denuded oocytes with COC decreased free intracellular zinc in the oocyte by 65%. Thus, cumulus cells suppress free intracellular zinc in the oocyte. The mRNA transcripts for the zinc transporter proteins Slc39a6, Slc39a8, Slc39a9, Slc39a10, Slc39a12, Slc30a2, Slc30a4, Slc30a5 and Slc30a8 mRNAs were higher in oocytes, while Slc39a1, Slc39a7, Slc39a13, Slc39a14, Slc30a6, Slc30a7 and Slc30a9 mRNAs were higher in cumulus cells. Thus a complex zinc transport network is present in the COC. Pretreatment with epidermal growth factor for 4 h abolished the ability of COCs to restrict free intracellular zinc in denuded oocytes. Coculture of denuded metaphase II oocytes with COC lowers free intracellular zinc in mature oocytes. Oocytes matured in vivo or oocytes from older mice had lower levels of free intracellular zinc than oocytes matured in vitro or from younger mice. Thus, a precise mechanism for regulating oocyte zinc homeostasis has been uncovered in the COC that is disrupted with increasing age or by removal of cumulus cells.
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Alvino, E. R., R. L. Robker, and D. L. Russell. "155. CD44 SIGNALLING IN THE CUMULUS OOCYTE COMPLEX DURING OVULATION." Reproduction, Fertility and Development 21, no. 9 (2009): 73. http://dx.doi.org/10.1071/srb09abs155.
Повний текст джерелаАнотація:
Oocytes develop within ovarian follicles that nurture and regulate oocyte maturation. The LH surge induces a cascade of gene expression leading to formation of the hyaluronan (HA) rich cumulus matrix around the oocyte. This cumulus oocyte complex (COC) is composed of high concentrations of HA cross-linked by several HA-binding proteins. Null mutation of several COC matrix genes results in ovulation defects demonstrating the importance of the composition and structure of the COC; but the mechanisms by which the matrix promotes ovulation are unknown. We hypothesised that HA, via activation of its receptor CD44 on cumulus cells, regulates cytoskeletal function, cell adhesion and migration, and that acquired cumulus cell motility facilitates ovulation. We investigated cellular signaling and cellular phenotypes occurring in response to the formation of the HA-rich COC matrix. Expression of CD44 was upregulated 5 to 6-fold in cumulus cells following 6 or 12h hCG (LH analog) stimulation. Signal transducers of CD44 action; Tiam1, a guanine exchange factor, and Rac1, an actin cytoskeleton remodelling Rho-family GTPase, were present in cumulus cells but not regulated by hCG. Induction of migratory and invasive capacity of cumulus cells by hCG was demonstrated using transwell migration and ECM invasion assays. Cumulus cell migration increased 8-fold 10h after hCG compared with cumulus cells from untreated mice. These cumulus cells also showed the capacity to invade through a matrigel barrier. Inhibitors of the CD44-assembled cell migration complex demonstrated the importance of this pathway in the migratory and invasive phenotype of cumulus cells. These results demonstrate that CD44 is a key factor in the assembly of a macromolecular complex facillitating cell motility in cumulus cells at the time of ovulation, and suggest that cumulus cells in the expanded COC undergo epithelial-mesenchymal transition to become invasive motile cells which may play a key role mediating ovulation.
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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.
Повний текст джерелаАнотація:
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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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.
Повний текст джерелаАнотація:
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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Lee, S. H., H. J. Oh, G. A. Kim, M. J. Kim, Y. B. Choi, Y. Kwang Jo, E. Nugraha Setyawan, and B. C. Lee. "212 EFFECT OF CANINE OVIDUCT CELLS AND CUMULUS CELLS CO-CULTURE ON IN VITRO MATURATION OF PORCINE OOCYTES AND EMBRYO DEVELOPMENT." Reproduction, Fertility and Development 28, no. 2 (2016): 237. http://dx.doi.org/10.1071/rdv28n2ab212.
Повний текст джерелаАнотація:
In oestrus stage, canine oocytes surrounded by cumulus cells undergo maturation in oviduct for 3 days after ovulation. We hypothesised that canine cumulus cells (cCC) and canine oviduct cells (cOC) in oestrus stage might affect the maturation of oocyte and embryo development. Therefore, the present study was aimed to compare the effects of cCC and cOC co-culture system on oocyte in vitro maturation and embryo in vitro development. cCC were separated from cumulus‐oocyte complex (COC) in ovary from bitches in oestrus phase. cOC were collected from oviduct flushing of bitches in oestrus phase. Both cCC and cOC were cultured and cryopreserved until use for co-culture. In the first experiment, the effect of co-culture using cCC and cOC on porcine oocyte in vitro maturation (IVM) were investigated. The porcine COC were randomly cultured in different co-culture groups as follows: 1) co-culturing with cCC for 42 h, 2) co-culturing with cOC for 42 h, and 3) culturing in absence of cCC or cOC. After IVM, extrusion of the first polar body was observed under a microscope. In the second experiment, the matured oocytes with the first polar body derived from each group were activated with electrical stimulus. Parthenotes were cultured in porcine zygote medium-5 (PZM-5) for 7 days at 39°C, 5% CO2 and O2 in a humidified atmosphere. The embryo developmental competence was estimated by assessing the in vitro development under microscope. The third experiment was to evaluate the reactive oxygen species (ROS) levels in each supernatant medium obtained from cCC and cOC co-culture group after IVM using a OxiselectTM ROS ELISA Assay kit. Last, analysis of genes (MAPK1/3, SMAD2/3, GDF9 and BMP15) expression in cCC and cOC co-cultured with porcine COC using real-time PCR is in progress. As results, IVM rate of cOC group (91.19 ± 0.45%) was significantly higher than that of cCC and control group (86.50 ± 0.61% and 79.81 ± 0.82%; P < 0.05). Also, cOC groups expressed the highest efficiency in cleavage rate, blastocyst formation rate, and the total cell number in blastocyst (P < 0.05). In ROS levels, cOC group (555 ± 7.77 nM) were significantly lower than cCC and control groups (596.8 ± 8.52 nM and 657.8 ± 11.34 nM). The present study demonstrated that co-culture with cOC improved the in vitro oocyte maturation and the in vitro development rate of porcine embryos. The ROS level decreased in cOC co-culture would have beneficial influence on oocytes maturation. For further study, we will investigate the relation between gene expression related to oocyte maturation and the co-culture results. This research was supported by a global PhD Fellowship Program through NRF funded by the Ministry of Education (NRF-20142A1021187), RDA (#PJ010928032015), IPET (#311011–05–4-SB010, #311062–04–3-SB010), Research Institute for Veterinary Science, and the BK21 plus program.
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Gupta, S. C., A. Pandey, and N. Gupta. "245 CONNEXIN 43 mRNA EXPRESSION AT DIFFERENT TIME POINT IN IN VITRO MATURATION OF BUFFALO OOCYTES." Reproduction, Fertility and Development 21, no. 1 (2009): 220. http://dx.doi.org/10.1071/rdv21n1ab245.
Повний текст джерелаАнотація:
In advanced technologies of ART, the basic requirement is the production of in vitro-matured oocytes, and embryo production efficiency depends on healthy, matured oocytes. Oocyte growth and development depends on the ability of oocytes and their surrounding cumulus granulosa cells (Eppig et al. 1979 J. Exp. Zool. 208, 111–120). Cumulus cells provide carbohydrate precursors, amino acids, and nucleotides to the oocytes (Brower and Schultz 1982 Dev. Biol. 90, 144–153). Oocytes and cumulus cell gap junctions are required for the coordination of cytoplasmic and nuclear maturation (Carabatsos et al. 2002 Dev. Biol. 226, 167–179). In bovine COC, functional gap junctions are required for the progression of oocyte maturation. Gap junctions allow for metabolic coupling between adjacent granulosa cells. Disruption in the integrity of the gap junction inhibits oocyte maturation (Anderson and Albertini 1976 J. Cell Biol. 71, 680–686). The aim of this study was to analyze the trend of Cx43 mRNA transcript in in vitro-matured oocytes at different times of maturation in the Indian water buffalo to estimate the correlation with expression level. Oocytes collected from slaughterhouse ovaries were matured in TCM-199 medium supplemented with 2.5 mm pyruvate, gentamycin sulfate (10 mg mL–1), β-estradiol (1000 ng mL–1), FSH (500 ng mL–1), LH (500 ng mL–1), and 10% FBS at 38.5°C in 5% CO2 in air. Cumulus–oocyte complexes were used after 0, 6, 12, 18, and 24 h of maturation for the cDNA preparation with cells of a cDNA II Kit. Expression of the Cx43 gene was quantified at different time intervals for maturation with real-time PCR. Statistical analysis was performed with one-way ANOVA, followed by Duncan’s multiple pair-wise comparison. Our results showed that Cx43 mRNA abundance was affected by time of maturation. The expression of Cx43 was significantly higher at 6 h than at 18 and 24 h, whereas the 12-h value was intermediate. Our results are in agreement with decreased Cx43 protein contents in the outer cumulus layers of COC at maturation time points (Calder et al. 2003 Reprod. Biol. Endocrinol. 1, 14) and the expression of Cx43 in oocyte development regulation (Granot et al. 2002 Biol. Reprod. 66, 568–573). When Cx43 expression was compared among immature oocytes, denuded oocytes, cumulus cells, and COC at 6 h, there was no significant difference. However, 6-h-matured COC showed significantly higher expression than other groups. Further, our study supported the role of cumulus cells in COC in Cx43-mediated communication (Vozzi et al. 2001 Reproduction 122, 619–628). Differential expression of Cx43 mRNA among varying COC classes indicates that this gene may be a useful marker for oocyte quality to improve in vitro production or somatic cell nuclear transfer rates. Marker genes that predict developmental competence could be used in the optimization of maturation and culture conditions. Understanding the molecular mechanism involved in in vitro oocyte maturation would be an additional advantage in analyzing this complex biological phenomenon to improve embryo production.
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Patel, O. V., A. Bettegowda, J. J. Ireland, and G. W. Smith. "261 IDENTIFICATION OF OOCYTE- AND CUMULUS-DERIVED CO-REGULATED AND DIFFERENTIALLY REGULATED TRANSCRIPTS ASSOCIATED WITH BOVINE MEIOTIC MATURATION." Reproduction, Fertility and Development 18, no. 2 (2006): 238. http://dx.doi.org/10.1071/rdv18n2ab261.
Повний текст джерелаАнотація:
Understanding the process of oocyte maturation is critical for efficient application of biotechnologies such as in vitro embryo production and nuclear transfer/cloning. Intercellular communication between the oocyte and the encompassing somatic (cumulus) cells is pivotal for successful growth of ovarian follicles and oocyte maturation. Therefore, we utilized global gene expression profiling to determine changes in the transcriptome of oocytes and their adjacent cumulus cells during meiotic maturation in vitro to identify both co-regulated and differentially regulated transcripts within the two cell compartments of the cumulus oocyte complex (COC). Germinal vesicle (GV) and in vitro matured metaphase II (MII) COC (n = 5 pools of 5 COC per group) were denuded and separated into oocytes and cumulus cells. RNA was extracted from the oocytes and cumulus cells and subjected separately to microarray analysis using a bovine cDNA array containing expressed sequence tags (ESTs) representing 15 500 unique genes. A combined total of 1045 genes displaying greater mRNA abundance in GV oocytes and associated cumulus cells compared to MII samples were detected (P < 0.05; false discovery rate (FDR) = 5%). A combined total of 711 genes displaying greater mRNA abundance in MII oocytes and enclosing cumulus cells compared to GV samples were detected (P < 0.05; FDR = 5%). Fourteen transcripts were identified that were co-regulated and of greater abundance in GV or MII oocytes and in their matching cumulus cells (P < 0.05; FDR = 5%). The co-regulated transcripts identified are implicated in metabolism (e.g. heme oxygenase-2, leukotriene B4 12-hydroxydehydrogenase), signal transduction (e.g. caveolin 1, ring finger protein 31), and cell growth (e.g. BTG family member 2, myosin regulatory light chain 2). In contrast, thirteen transcripts differentially regulated in the GV oocyte versus MII cumulus cells were identified (P < 0.05; FDR = 5%). Similarly, nine transcripts differentially regulated in the MII oocyte versus GV cumulus cells were identified (P < 0.05; FDR = 5%). Some of the identified differentially regulated transcripts encode for genes associated with the cytoskeleton (e.g. tropomyosin 1), apoptotic activity (e.g. death effector domain containing protein 2) and DNA replication (e.g. epsilon polymerase). The results provide novel insights into the identity of transcripts whose abundance is co-regulated or differentially regulated between the oocyte and cumulus cells during the transition of a COC from the GV to the MII stage. Characterization of the signaling pathways driving changes in transcript abundance for co-regulated and differentially regulated genes in oocytes versus associated cumulus cells may lead to a better understanding of regulation of meiotic maturation and potential cross-talk between germ cells and somatic cells during the oocyte maturation cascade. This work was supported by the Rackham Foundation and the MI Agriculture Experiment Station.
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Gutnisky, Cynthia, Gabriel C. Dalvit, Laura N. Pintos, Jeremy G. Thompson, Martha T. Beconi, and Pablo D. Cetica. "Influence of hyaluronic acid synthesis and cumulus mucification on bovine oocyte in vitro maturation, fertilisation and embryo development." Reproduction, Fertility and Development 19, no. 3 (2007): 488. http://dx.doi.org/10.1071/rd06134.
Повний текст джерелаАнотація:
During cumulus–oocyte complex (COC) maturation, cumulus expansion involves the deposition of mucoelastic compounds, especially hyaluronic acid, synthesised from glucose via the hexosamine biosynthesis pathway. The aim of the present study was to determine the effects of uridine monophosphate (UMP) and 6-diazo-5-oxo-l-norleucine (DON), inhibitors of hyaluronic acid synthesis, during bovine oocyte in vitro maturation (IVM) on cumulus expansion, glucose uptake, protein synthesis, cumulus cell number, meiotic maturation, cleavage rate and subsequent embryo development. A further aim of the study was to examine the effect of hyaluronic acid on sperm capacitation and acrosome reaction in relation to the capacity of COCs to be fertilised in vitro. A low correlation between glucose uptake and degree of cumulus expansion was observed. Total and partial inhibition of cumulus expansion was observed with DON and UMP, respectively, and was accompanied by a decrease in glucose uptake with DON. Total protein content and cumulus cell number per COC increased during IVM, but was unaffected by the presence of DON or UMP, as was oocyte meiotic maturation. Rates of cleavage and blastocyst development decreased in oocytes matured with DON and UMP, although this inhibition was reversed when the in vitro fertilisation (IVF) medium contained heparin. Hyaluronic acid induced capacitation and the acrosome reaction, and in IVF medium prevented the inhibition of cleavage and blastocyst development by DON in a similar fashion to heparin. Hyaluronic acid synthesis during cumulus mucification contributes to the penetration and fertilisation of bovine oocytes, most likely by facilitating the processes of capacitation and acrosome reaction. Mucification during IVM is independent of cumulus cell proliferation, COC protein content, oocyte meiotic maturation and subsequent developmental competence once fertilised.
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Alvino, E. R., R. L. Robker, and D. L. Russell. "269. CD44 signaling in mouse ovulatory cumulus - oocyte complexes." Reproduction, Fertility and Development 20, no. 9 (2008): 69. http://dx.doi.org/10.1071/srb08abs269.
Повний текст джерелаАнотація:
Oocytes grow and develop within ovarian follicles, providing a nurturing environment before their release (ovulation) into the oviduct for fertilisation. For ovulation to occur the ovarian follicle responds to LH from the pituitary, leading to a cascade of regulated gene expression and formation of the hyaluronan rich cumulus matrix around the oocyte. This COC (cumulus oocyte complex) matrix is composed of high concentrations of the ECM glycosaminoglycan hyaluronan (HA) cross-linked by several HA-binding proteins. Several of the COC matrix components are essential for ovulation, since null gene mutations in mice lead to ovulation defects. Mechanisms by which the COC matrix controls ovulation however, are unknown. We have investigated cellular signalling and cellular phenotypes that occur as part of the formation of the COC matrix. The transmembrane HA receptor CD44 was significantly upregulated in cumulus cells from 6 h after hCG (LH analogue) treatment (9.8 ± 1.5 fold) until ovulation at 12 h post hCG (11.8 ± 2.9-fold). In many cell types CD44 activates the intracellular Rho-family GTPase Rac1 and its activator, the guanine exchange factor Tiam1, pleiotropic regulators of cytoskeletal function, cell-cell adhesion and migration. We found both Rac1 and Tiam1 were strongly detected in cumulus cells, but not regulated by hCG. These observations show that at the time of ovulation a macro-molecular complex associated with cell motility is assembled through the extracellular interaction of the COC matrix and cell surface proteins. We investigated the migratory and invasive activity of COCs from hormonally stimulated mice. Migration of cumulus cells from hCG treated mice was significantly increased compared with untreated COCs. Furthermore the hCG-stimulated cumulus cells were able to invade a range of ECM substrates including collagen and laminin. These results suggest the cumulus cells in the expanded COC transition to a motile cell phenotype that may play a key role in promoting ovulation.
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Uhde, K., L. T. A. van Tol, T. A. E. Stout, and B. A. J. Roelen. "79 microRNA EXPRESSION IN BOVINE CUMULUS CELLS." Reproduction, Fertility and Development 27, no. 1 (2015): 133. http://dx.doi.org/10.1071/rdv27n1ab79.
Повний текст джерелаАнотація:
A mammalian oocyte within an ovarian follicle is surrounded by cumulus cells, together this structure is known as the cumulus-oocyte complex (COC). Cumulus cells are important for the development of the oocyte, they support the maturation process of the oocyte within the ovary and aid in sperm recognition. Because it is known that a Dicer knockout leads to infertility, microRNAs (miRNA) are focused to have an important role in oocyte development. MiRNAs are small noncoding RNA sequences that act as transcriptional regulators. Little is known about the expression of miRNA in cumulus cells or how cumulus-derived miRNA may regulate or be used to indicate the developmental competence of the maturing oocyte. Our aim was to investigate miRNA expression in oocytes and to identify and establish how specific miRNA influence the acquisition of developmental competence by bovine oocytes. Normalization of qPCR data requires stable reference genes. To this end, we tested the expression of various miRNA with respect to their ability to be used as reference miRNA for bovine cumulus cells; these included miR-103, miR-93, miR-26, let-7a, miR-191, and the small noncoding nuclear RNA U6. Cumulus-oocyte complexes were recovered from the ovaries of slaughtered cows and matured in vitro. Small samples of cumulus cells were collected from these COC before and after maturation. From the cumulus cell groups recovered at different stages, small RNA were extracted and cDNA was synthesised, followed by qRT-PCR. To identify the optimal combination of reference genes, the geNorm algorithm was used. MiR-26a and let-7a were identified as the most stably expressed miRNAs, whereas U6 showed the most variable expression levels. Future investigations are planned to identify miRNA in cumulus cells that can be used as markers for oocyte developmental competence. Using a single oocyte-embryo culture system will enable us to retrospectively relate cumulus miRNA expression to the developmental capacity of the oocyte.This work was supported by EU FP7 EpiHealthNet (N°317146).
Дисертації з теми "Cumulus oocyte complex (COC)"
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Sanches, Lorena. "Efeitos do fator de crescimento dos fibroblastos 8 (fgf8) na maturação in vitro de complexos cumulus-oócito bovinos." Botucatu, 2016. http://hdl.handle.net/11449/143787.
Повний текст джерелаАнотація:
Orientador: José Buratini JúniorResumo: A maturação in vitro (MIV) é uma etapa fundamental da produção in vitro de embriões bovinos (PIV). A conclusão prematura da maturação nuclear durante a MIV é considerada como uma das principais causas da eficiência limitada da PIV. Em camundongos, o fator de crescimento dos fibroblastos 8 (FGF8) regula a atividade do peptÌdeo natriurético tipo C (NPPC) aumentando a expressão de seu receptor (NPR2) e contribuindo assim para o bloqueio meiótico. O principal objetivo deste trabalho foi testar os efeitos do FGF8 sobre a dinâmica da quebra da vesícula germinativa e progresso da meiose durante a MIV induzida com FSH ou ampirregulina (AREG) em bovinos. Paralelamente, os efeitos do FGF8 sobre a expansão do cumulus e metabolismo da glicose também foram testados. Na MIV induzida com AREG, mas não com FSH, o FGF8 diminuiu a porcentagem de oócitos com quebra da vesícula germinativa às 6 e 9 horas do cultivo, enquanto aumentou a expressão do RNAm do NPPC, mas não do NPR2, nas células do cumulus. Distintamente, na MIV com FSH, o FGF8 diminuiu a porcentagem de oócitos em Meiose I às 9 horas de cultivo. O FGF8 não afetou a porcentagem de oócitos em Meiose II às 22 horas da MIV, nem a expansão do cumulus, embora tenha aumentado a expressão do RNAm de genes da cascata ovulatória [prostaglandina endoperoxido sintase 2 (PTGS2) e desintegrina e metaloproteinase de domínio contendo proteÌna 10 (ADAM 10)]. Além disso, o FGF8 diminuiu o consumo de glicose e a produção de lactato na MIV com FSH, m... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
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Sanches, Lorena [UNESP]. "Efeitos do fator de crescimento dos fibroblastos 8 (fgf8) na maturação in vitro de complexos cumulus-oócito bovinos." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143787.
Повний текст джерелаАнотація:
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A maturação in vitro (MIV) é uma etapa fundamental da produção in vitro de embriões bovinos (PIV). A conclusão prematura da maturação nuclear durante a MIV é considerada como uma das principais causas da eficiência limitada da PIV. Em camundongos, o fator de crescimento dos fibroblastos 8 (FGF8) regula a atividade do peptÌdeo natriurético tipo C (NPPC) aumentando a expressão de seu receptor (NPR2) e contribuindo assim para o bloqueio meiótico. O principal objetivo deste trabalho foi testar os efeitos do FGF8 sobre a dinâmica da quebra da vesícula germinativa e progresso da meiose durante a MIV induzida com FSH ou ampirregulina (AREG) em bovinos. Paralelamente, os efeitos do FGF8 sobre a expansão do cumulus e metabolismo da glicose também foram testados. Na MIV induzida com AREG, mas não com FSH, o FGF8 diminuiu a porcentagem de oócitos com quebra da vesícula germinativa às 6 e 9 horas do cultivo, enquanto aumentou a expressão do RNAm do NPPC, mas não do NPR2, nas células do cumulus. Distintamente, na MIV com FSH, o FGF8 diminuiu a porcentagem de oócitos em Meiose I às 9 horas de cultivo. O FGF8 não afetou a porcentagem de oócitos em Meiose II às 22 horas da MIV, nem a expansão do cumulus, embora tenha aumentado a expressão do RNAm de genes da cascata ovulatória [prostaglandina endoperoxido sintase 2 (PTGS2) e desintegrina e metaloproteinase de domínio contendo proteÌna 10 (ADAM 10)]. Além disso, o FGF8 diminuiu o consumo de glicose e a produção de lactato na MIV com FSH, mas não com AREG. Em conclusão, o FGF8 desacelera a dinâmica da maturação nuclear enquanto aumento a expressão do NPPC nas células do cumulus durante MIV induzida com AREG e, portanto, apresenta-se como fator potencialmente útil para melhorar a eficiÍncia da MIV.
FAPESP: 2012/06417-8
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Abd-el-Naby, Walaa Slouma Hamouda [Verfasser]. "Expression analysis of regulatory MicroRNA in bovine cumulus oocyte complex and preimplantation embryos / Walaa Slouma Hamouda Abd El Naby." Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/1043054782/34.
Повний текст джерела
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Lemes, Rafaella Curvelano. "Análise do perfil de expressão gênica de oócitos bovinos advindos de complexos cumulus-oócito com diferentes qualidades morfológicas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/17/17135/tde-29082013-163547/.
Повний текст джерелаАнотація:
A busca por melhores resultados nas biotecnologias reprodutivas leva a um estudo dos mecanismos fisiológicos básicos dos gametas e embriões em estágios iniciais. Entender como funciona o desenvolvimento destes, quais os nutrientes que eles precisam para se desenvolver in vitro e quais as condições ambientais necessárias permitem maiores taxas de sucesso. Tendo em vista a heterogeneidade dos complexos cumulus-oócito (COC) bovinos recuperados de ovários obtidos em frigorífico para a maturação in vitro e a relação entre oócito e células do cumulus nos resultados da produção in vitro de embriões, esse trabalho visa a identificação de fatores moleculares que possam explicar as melhores taxas de blastocistos obtidas por COCs com mais de três camadas de células do cumulus compactas e ooplasma homogêneo (COCI) quando comparados com COCs com menos de duas camadas de células do cumulus, com parte da zona pelúcida exposta e ooplasma homogêneo ou heterogêneo (COCIII). Para isso, COCI e III foram maturados in vitro separadamente, foram vortexados para retirada das células do cumulus e os oócitos foram submetidos a extração de RNA. O RNA foi amplificado em aRNA, marcado com biotina, fragmentado e hibridizado em microarray. Os arrays foram escaneados e os dados gerados analisados pelo métodos Significance Analysis of Microarrays e Rank Products em busca de genes diferencialmente expressos (DEG). A análise funcional in silico foi realizada com a ferramenta Ingenuity Pathway Analysis. Os resultados mostraram que o perfil de expressão dos oócitos de COCIII é diferente do perfil dos oócitos de COCI, como pode ser observado pelos 446 DEGs identificados, sendo 24 com expressão aumentada em oócitos de COCIII. Os genes com expressão alterada estão envolvidos em processos básicos da célula, como reassumição da meiose, metabolismo do oócito e maturação molecular, o que corrobora a ideia de que uma grande quantidade de células do cumulus interagindo com o oócito é crucial para a competência de desenvolvimento.The researches for better results in reproductive biotechnologies have leading to studies of the basic physiological mechanisms of gametes and embryos in the early stages of developmental. Understand about their development, which nutrients they need and what environmental conditions are necessary to allow higher success rates. Because of the cumulus-oocyte complexes (COC) heterogeneous recovered from bovine ovaries obtained from an abattoir used for in vitro maturation and the relationship between oocyte and cumulus cells in the in vitro production of embryos, this study aims to identify molecular factors which might explain the improved rates of blastocyst obtained by COCs with more than three compact layers of cumulus cells and homogeneous ooplasm (COCI) compared with COC with less than two layers of cumulus cells, with part of the zona pellucida exposed and homogeneous or heterogeneous ooplasm (COCIII). For this, COCI and III were matured in vitro separately, their cumulus cells were removed and oocytes were subjected to RNA extraction. The RNA was amplified in aRNA, biotin labeled, fragmented and hybridized on microarray. The arrays were scanned and the data generated analyzed by the Significance Analysis of Microarrays and Rank Products methods in search of differentially expressed genes (DEG). In silico functional analysis were performed using Ingenuity Pathway Analysis. The results showed that the expression profile of COCIII oocytes is different from the profile of COCI oocytes. 446 DEGs were identified of which 24 presented increased expression in COCIII oocytes. Genes with altered expression are, in general, involved in the basic processes of the cell, as reassume of meiosis, metabolism of the oocyte and molecular maturation, which confirms the idea that a large amount of cumulus cells interacting with the oocyte is crucial for the development of competence.
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Brisard, Daphné. "Etude de la maturation ovocytaire chez les vaches : effet de l'haplotype pour QTL-FERT-F-BTA3 et effet du métabolisme lipidique." Thesis, Tours, 2014. http://www.theses.fr/2014TOUR4003.
Повний текст джерелаАнотація:
Chez la vache Prim’Holstein, un QTL de fertilité a été localisé sur le chromosome 3, et deux haplotypes ont été déterminés : « Fertil+ » et « Fertil- ». Les « Fertil- » ont un plus fort taux d’échec de gestation précoce. Le 1er objectif de cette thèse était de déterminer si un dysfonctionnement des complexes ovocyte-cumulus (COC) pouvait expliquer l’échec précoce de gestation chez les « Fertil- ». L’analyse révèle un retard de maturation, une dérégulation de gènes appartenant aux voies des prostaglandines et des MAPK, et à la famille des Tribbles dans les CC ou l’ovocyte des « Fertil- ». Trois gènes composent la famille des Tribbles chez le bovin: TRIB1, TRIB2 et TRIB3, leur fonction est indéterminée dans le COC. Le 2nd objectif était de caractériser le patron d’expression des Tribbles et leur(s) fonction(s) au sein du COC bovin. Les Tribbles joueraient un rôle dans le métabolisme lipidique et l’inflammation au niveau folliculaire. Le métabolisme lipidique au sein du COC bovin étant peu caractérisé, le 3ème objectif était d’appréhender les profils des gènes du métabolisme des acides gras (AG) dans les CC au cours de la maturation. Ainsi, les CC expriment les gènes lipotytiques et lipogéniques. Enfin, la β-oxydation des AG est une fonction primordiale pour la maturation ovocytaireIn Prim’Holstein cow, a fertility QTL was localized on chromosome 3 and two haplotypes were determined: « Fertil+ » and « Fertil- ». « Fertil- » have a higher early pregnancy failure rate. The 1st objective of the thesis was to define if complex oocyte-cumulus COC dysfunction could explain the early pregnancy failure in « Fertil- ». Analysis highlighted a maturation delay, a dysregulation of genes involved in prostaglandin and MAPK pathway along with one member of the Tribbles family in « Fertil- » CC or oocyte. In bovine, the Tribbles family is composed of three genes: TRIB1, TRIB2 and TRIB3, their function is unknown within the COC. The 2nd objective was to characterize the Tribbles expression pattern and their function in the bovine COC. The tribbles might play a role in lipid metabolism and in inflammation at the follicular level. Lipid metabolism within bovine COC is poorly understood, thus the third objective was to apprehend fatty acid (FA) genes pattern in CC during maturation. Thus, CC express lipolytic and lipogenic genes. Lastly, FA β oxidation is found to be important for oocyte maturation
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Salviano, Mauricio Barbosa. "Estratégias para indução de competência de oócitos bovinos com atividade da enzima glicose 6-fosfato desidrogenase." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/108180.
Повний текст джерелаАнотація:
O objetivo deste trabalho foi modificar os procedimentos da maturação in vitro (MIV) para induzir a competência de oócitos bovinos com intensa atividade da enzima glicose 6-fosfato desidrogenase (G6PDH), determinada pelo emprego do corante vital Azul de Cresil Brilhante (BCB). Foram realizados dois experimentos; no primeiro trabalho foi realizada a MIV de oócitos após a identificação da atividade da G6PDH, empregando-se a seguinte proporção: competentes (sem atividade enzimática)/não competentes - 10:01, respectivamente. Os resultados revelaram um efeito negativo dos oócitos não competentes sobre a capacidade dos competentes em realizarem a MIV, a FIV e a CIV. Os resultados sugerem que para aumentar a produção de embriões deve-se realizar a MIV de oócitos competentes e não competentes, separadamente. O objetivo do segundo experimento foi verificar se a prolongação do tempo de MIV (30h) afetaria as taxas de MIV, FIV e CIV obtidas a partir de oócitos não competentes. Os oócitos não competentes não foram afetados, positiva ou negativamente, pelo prolongamento do tempo de MIV, no entanto, os oócitos competentes sofreram decréscimo na capacidade de serem fecundados e desenvolverem-se até o estágio de blastocistos. Podemos concluir que as modificações realizadas no procedimento da MIV não foram capazes de induzir competência em oócitos com intensa atividade da enzima G6PDH.The present work aimed modify the in vitro maturation (IVM) procedure to induce competence of bovine oocytes with high glucose 6-phosphate dehydrogenase (G6PDH) activity. Two experiments were carried out; the first non-competent oocytes (with high enzymatic activity) were matured with competent oocyte (lower G6PDH activity) on proportion of 1:10, respectively. The second experiment aimed observe the effect of prolonged IVM (from 24 to 30h) on the cleavage and development rates in oocytes with higher enzymatic activity. Our data showed that oocytes with lower enzymatic activity did not induce competence of higher G6PDH activity oocyte. However, we observed a negatively effect on the cleavage and development rates on oocytes competent, then, to increase the number of embryos in vitro produced we need to mature oocytes competent and non-competent separately. In the second experiment, the non-competent gametes submitted to prolonged IVM were not affected, however, competent oocytes were negatively affect by prolonged IVM. We can concluded that the IVM modifications did not able to induce the competence in the oocytes with high G6PDH activity.
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Alvino, Emily Renee. "The role of the cumulus oocyte complex during ovulation." Thesis, 2011. http://hdl.handle.net/2440/66194.
Повний текст джерелаАнотація:
Ovulation is fundamentally crucial to the reproductive success of all mammals. Despite this fact there remain major knowledge gaps in our understanding of how the Luteinizing Hormone (LH) surge, which initiates ovulation, controls this process. There have been numerous theories regarding this phenomenon, yet the underlying mechanisms involved remain relatively unknown. In this thesis I sought to elucidate mechanisms involved in ovulation, with a particular focus on the role played by the expanded cumulus oocyte complex (COC). Specifically, I investigate whether the cumulus cells and their associated matrix following expansion could contribute actively to its own extrusion from the ovarian follicle during ovulation. I developed a novel hypothesis whereby the cumulus cells transition to an adhesive, motile and invasive cell phenotype in response to an ovulatory stimulus, hCG an analog of LH. I investigate whether the cumulus cells from expanded COCs are capable of cell adhesion to various extracellular matrices found in the follicle wall, and whether this is dependent upon hormonal stimulation by comparison to cumulus cells from unexpanded COCs, not receiving such stimulation. Further, I investigate whether the cumulus oocyte complex is capable of transitioning to a migratory cell phenotype. I tested this with established methods used in the study of cancer cell metastasis. I determine whether this phenotype is firstly dependent on an ovulatory stimulus, and whether it is cumulus cell specific. I attempt to elucidate the molecular mechanisms involved by investigating expression of the well-characterised CD44 cell migration pathway in COCs, during an ovulation time-course. I then use specific antagonists to this pathway, to inhibit cell migration. The final step in our hypothesis involves the investigation of the invasive capacity of the expanded COC. I analyse whether the expanded COCs are capable of degrading an extracellular matrix barrier during migration assays, and I compare this ability to characterised invasive and non-invasive breast cancer cell lines. I also investigate possible mechanisms involved in the invasive phenotype by inhibiting the matrix metalloprotease system, proposed to play an important role in the degradation of the follicle wall during follicle rupture, and by examining the Adamts1 null mouse, as Adamts1 is a protease shown to be crucial during ovulation. This thesis demonstrates novel and exciting properties of the cumulus oocyte complex during ovulation; offering new insight into our understanding of this complex process. It shows that the oocyte and its surrounding cumulus cells are not merely a passive entity, as previously thought, but rather may play an active role during this vital reproductive process.Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2011
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Akison, Lisa Kathleen. "The role of nuclear progesterone receptor (PGR) in regulating gene expression, morphology and function in the ovary and oviduct during the periovulatory period." Thesis, 2013. http://hdl.handle.net/2440/81059.
Повний текст джерелаАнотація:
Ovulation requires sequential molecular events and structural remodelling in the ovarian follicle for the successful release of a mature oocyte into the oviduct. Critical to this process is progesterone receptor (PGR), a transcription factor highly yet transiently expressed in granulosa cells (GC) of preovulatory follicles and abundant in the oviduct. Progesterone receptor knockout (PRKO) mice are anovulatory, with a specific and complete defect in follicle rupture. Therefore, this model was used to examine the critical molecular and biochemical mechanisms necessary for successful ovulation. Progesterone is known to affect oviductal cells in vitro, but how PGR regulates oviductal structure and function is poorly understood. A systematic evaluation of ovarian and oviductal morphology during the periovulatory period revealed no structural defects in PRKO mice relative to heterozygous (PR+/-) littermates. However, in response to the LH surge/hCG treatment, ovulation only occurred in PR+/- ovaries, with numerous corpora lutea observed and cumulus oocyte complexes (COCs) in oviducts, while PRKO ovaries did not ovulate and showed entrapped COCs within large, luteinising follicles. Transplantation of PRKO ovaries into wild-type mice (PRWT) did not rescue the infertility phenotype. Therefore, although PGR is expressed in other tissues, ovarian PGR is essential for ovulation. Further experiments identified PGR-regulated processes at multiple levels. In whole ovaries 10 h post-hCG, inflammatory genes were disrupted in PRKO mice, including cytokines, endothelial adhesion factors, vasoconstrictors, T-cell antigens, and the prostaglandin synthase, Ptgs2. In GCs and COCs isolated 8 h post-hCG, microarray analyses identified 296 and 44 differentially expressed genes respectively between PRKO and PR+/- samples. Gene ontology analysis revealed associations with the processes of proteolysis, vascular remodelling/angiogenesis, inflammatory responses, cell adhesion, migration and invasion. The latter three processes were characterised in periovulatory COCs using in vitro assays and were shown to be transiently activated, peaking at ovulation then declining dramatically in COCs collected from the oviduct immediately post-ovulation. However, periovulatory PRKO and PR+/- COCs showed similar rates of adhesion, migration and invasion in the presence of collagen I. Upregulation of the chemokine receptor, Cxcr4, by LH/hCG via PGR in both GCs and COCs was validated by RT-PCR and immunohistochemistry. Mitochondrial membrane potential was altered in PRKO oocytes compared to PR+/- and therefore their developmental potential may be reduced. Further, a bioassay measuring retention of prostaglandin (PGE2) within the matrix of expanded COCs suggested that the matrix integrity of PRKO COCs may be compromised. Therefore, PGR in granulosa cells appears to have down-stream impacts on COCs. In oviducts, microarray analysis comparing gene expression in PRKO and PR+/- mice 8 h post-hCG, when P4 levels are high, identified 1003 PGR-regulated genes. Gene ontology analysis identified significant associations with the functions of cell adhesion, migration, invasion, chemotaxis, muscle contraction and vasoconstriction. Several genes were confirmed to be PGR-regulated by RT-PCR (Adamts1, Itga8 and Edn3) and were induced by LH/hCG. Therefore, the identification of novel gene targets for PGR regulation in the ovary and oviduct exposes several new, down-stream influences of PGR on inflammation, the COC and oviductal function, highlighting the essential role of PGR as master regulator in the ovary and oviduct during the periovulatory period.Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2013
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Frank, Laura Alice. "The role of the hexosamine biosynthesis pathway and β-O-linked glycosylation in determining oocyte developmental competence". Thesis, 2012. http://hdl.handle.net/2440/96463.
Повний текст джерелаАнотація:
Maternal diabetes and conditions such as obesity in which blood glucose levels are elevated are associated with reduced fertility and poor pregnancy outcomes. Many studies have examined the effects of hyperglycaemia on the early embryo and fetus; however, it is becoming increasingly evident that the peri-conceptual environment surrounding the oocyte has a significant impact on developmental competence and the long-term health of offspring. In this thesis, I aimed to investigate the role of the hexosamine biosynthesis pathway (HBP) in oocyte developmental competence. The HBP is a glucose-metabolising pathway which can also be upregulated by glucosamine, a potent hyperglycaemic mimetic which enters the HBP downstream of the rate-limiting enzyme. The HBP produces uridine diphosphate-N acetylglucosamine, which can be used for the β-O-linked glycosylation (O-GlcNAcylation) of proteins, regulating their function in a similar manner to phosphorylation. Firstly I established the effect of hyper- and hypo-glycaemic conditions during in vitro maturation (IVM) of mouse cumulus-oocyte complexes (COCs) on a range of measures associated with oocyte developmental competence, including cumulus expansion, meiotic maturation, cleavage and blastocyst development rates. A low (1 mM) glucose concentration achieved optimal oocyte competence, and glucose supplementation during only the first hour of IVM was necessary and sufficient to support oocyte maturation and embryo development to the blastocyst stage. Glucosamine was able to substitute for glucose during this first hour. In the absence of glucose throughout IVM, glucosamine was not able to increase developmental competence, and at higher concentrations (2.5 and 5 mM) had a detrimental effect on these outcomes. These experiments underscored the importance of the other glucose metabolic pathways, during COC maturation, and supported the concept that excess flux through the HBP has detrimental consequences. Using Western blots and immunohistochemistry, it was shown that both glucosamine and high glucose levels induced an increase in total O-GlcNAcylation in COCs, which was reduced in the presence of an inhibitor of the β-O-linked glycosyltransferase enzyme. Several specific proteins were identified using mass spectrometry as potential targets of O-GlcNAcylation in COCs, including heat-shock protein 90 (HSP90, both α and β isoforms). While glucosamine treatment of COCs significantly decreased blastocyst development rate, inhibiting HSP90 with 17-allylamino-17-demethoxygeldanamycin during IVM in the presence of glucosamine recovered blastocyst rates to control levels. This effect was not due to an increase in overall HSP90 levels, since inhibiting HSP90 in control COCs did not affect blastocyst rate. These results suggest O-GlcNacylated HSP90 has an aberrant function in the COC. This study is the first to examine in detail O-GlcNAcylation levels in the COC, and their correlation to oocyte developmental competence. HSP90 was identified as a potential target of O-GlcNAcylation in the COC, and subsequently shown to mediate oocyte developmental competence. This research is significant because of the increasing numbers of women wishing to become pregnant who have high blood glucose levels due to diabetes, obesity or poor diet. I have generated critically needed knowledge towards understanding how these lifestyle factors affect fertility and identifying possible avenues for new therapies.Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2012
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McLennan, Hanna Julie. "Detecting in vitro signals from the cumulus-oocyte-complex and spermatozoon as diagnostic tools: An examination of specific fluorophores and functionalised optical fibres." Thesis, 2020. https://hdl.handle.net/2440/136226.
Повний текст джерелаАнотація:
Includes Supplementary Videos 1-9.During in vitro maturation (IVM) and fertilisation (IVF), the oocyte and spermatozoon produce signals that could inform us about the developmental capacity of the resulting embryo. Non-invasive detection of these signals could enable the selection of the best embryo for transfer in both clinical and livestock embryology. Although some signals are well established within the oocyte, such as pulsatile calcium transients during oocyte activation, they have not been studied extensively in large mammals or intact cumulus-oocyte-complexes (COCs). In this thesis, I aimed to investigate some of the signals produced by COCs and uncapacitated spermatozoa before testing optical fibre technologies as a non-invasive signal detection method. As zinc ion release from the oocyte following oocyte activation is well established in the literature, I started with quantifying calcium behaviour during IVF in the intact cattle COC. This was a result of pilot data showing calcium fluorescence release from cumulus cells during fertilisation. My results showed there was a clear discharge of fluorescence from the cumulus cells corresponding with oocyte activation timing in cattle. Various experimental controls addressing probe toxicity, light toxicity, sperm presence, calcium chelation, artificial activation and active fluorophore efflux demonstrated that the discharge was an artefact of the imaging procedure. However, the degree of co-ordination of this discharge had a relationship with sperm presence and further embryo development that warrants further investigation of cumulus cell function during fertilisation. Next, I assessed the spermatozoa of bulls with known artificial insemination (AI) potential using their fluorescently labelled zinc signature. The results of this study found no relationship between zinc signature, AI success or further computer-assisted sperm analysis (CASA) parameters. Due to extenuating circumstances, the sperm staining parameters could not be compared with IVF outcomes for all bulls. Interestingly, the two IVF tested bulls performed inversely to their AI potential. Finally, I collaborated with a transdisciplinary team to determine whether functionalised optical fibres were an appropriate platform to detect biologically significant changes in the microenvironment immediately adjacent to the COC. Using a well characterised pH sensing optical fibre, differences of 0.01 - 0.05 pH units were discriminated between untreated COCs and those treated to stimulate cumulus cell lactic acid production with either cobalt chloride (CoCl2) or follicle stimulating hormone (FSH) in cattle and mouse COCs during IVM. I furthered this work with preliminary testing of a new functionalised holding pipette system during cattle IVF, quantitatively measuring protein carbonyls as a proxy measure for increased metabolism. This work is the first to consider and examine the role of cumulus cells in a livestock model at the time of oocyte activation and show that cumulus cells react to the presence of sperm in some manner. In addition, this work highlights in vivo and in vitro fertilisation capacity of individual bulls as an area for further research. Finally, this work has demonstrated that functionalised optical surfaces, including holding pipettes already utilised during intra-cytoplasmic sperm injection, have a potential future in noninvasively detecting diagnostic signals from the COC, and feasibly the embryo, during in vitro culture.
Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 2020
Частини книг з теми "Cumulus oocyte complex (COC)"
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Larsen, William J., Susan E. Wert, Lin Chen, Paul Russell, and E. Michael Hendrix. "Expansion of the Cumulus-Oocyte Complex During the Preovulatory Period: Possible Roles in Oocyte Maturation, Ovulation, and Fertilization." In Ultrastructure of the Ovary, 45–61. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3944-5_3.
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Downs, Stephen M. "Maturation of the Oocyte-Cumulus Cell Complex in Mice: Specificity of Epidermal Growth Factor Activity." In Growth Factors and the Ovary, 221–25. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-5688-2_23.
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Athanasiou, Georgios, Jesus Cerquides, Annelies Raes, Nima Azari-Dolatabad, Daniel Angel-Velez, Ann Van Soom, and Josep-Lluis Arcos. "Detecting the Area of Bovine Cumulus Oocyte Complexes Using Deep Learning and Semantic Segmentation." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2022. http://dx.doi.org/10.3233/faia220346.
Повний текст джерелаАнотація:
The cumulus-oocyte complex (COC) is an oocyte surrounded by specialized granulosa cells, called cumulus cells. The cumulus cells surrounding the oocyte ensure healthy oocyte and embryo development. The maturity of COCs at oocyte retrieval may be used as an indicator to predict outcome of assisted reproductive technology (ART). Segmenting COCs is a preliminary step in many image processing pipelines to evaluate maturity. However, acquiring well-annotated bright-field microscopy image datasets remains a time-consuming and inaccurate procedure, for most biological domains. Additionally, specialists often partially disagree on their annotations, not only among each other, but also among their own annotations, leading to an inconsistent outcome. Despite the recent advancements in deep learning and image segmentation tools for biological and biomedical images, there is limited usage of them for having more accurate and automated procedures. In this work, we propose an automated pipeline to segment bovine COCs in bright-field microscopy images. The results of our evaluation show that our pipeline is able to segment COCs with the same level of quality as provided by human experts.
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"Preparation for Follicle Aspiration and Isolation of Cumulus-Oocyte-Complexes (COC)." In Standard Operational Procedures in Reproductive Medicine, 30–31. CRC Press, 2017. http://dx.doi.org/10.1201/9781315270975-11.
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Rao, Kamini, and Divyashree PS. "Oocyte Cumulus Complex Evaluation." In Principles and Practice of Assisted Reproductive Technology (3 Volumes), 1205. Jaypee Brothers Medical Publishers (P) Ltd., 2014. http://dx.doi.org/10.5005/jp/books/12151_116.
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Rao, Kamini, and Divyashree PS. "Oocyte Cumulus Complex Evaluation." In Principles and Practice of Assisted Reproductive Technology, 1441. Jaypee Brothers Medical Publishers (P) Ltd., 2019. http://dx.doi.org/10.5005/jp/books/18020_116.
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Yokoo, Masaki, and Eimei Sato. "Cumulus–Oocyte Complex Interactions During Oocyte Maturation." In International Review of Cytology, 251–91. Elsevier, 2004. http://dx.doi.org/10.1016/s0074-7696(04)35006-0.
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Di Giacomo, Monica, Antonella Camaioni, and Antonietta Salustri. "APOPTOSIS AND HYALURONAN-ENRICHED EXTRACELLULAR MATRIX DEGRADATION IN CUMULUS CELL-OOCYTE COMPLEX: IMPLICATION IN FERTILITY." In Hyaluronan, 489–95. Elsevier, 2002. http://dx.doi.org/10.1533/9781845693121.489.
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Carr, Bruce R., and Victor E. Beshay. "Fertilization, Implantation, and Endocrinology of Pregnancy." In Textbook of Endocrine Physiology. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199744121.003.0013.
Повний текст джерелаАнотація:
The complex and coordinated set of events leading to sperm and egg maturation and transport in the female genital tract that culminates in fertilization is one of the most remarkable phenomena in nature. This set of events is followed by the equally important unique processes of implantation, fetal maturation, and parturition. The hormonal changes that regulate these events are dependent on the close interaction of the fetal-placental-maternal unit. Just before ovulation, the egg, which has been arrested in the diplotene stage, completes the first meiotic division and forms the first polar body. The second meiotic division starts at the time of ovulation but ends only after fertilization by a sperm. The process of egg maturation is regulated through a closely interrelated set of hormonal events, most notably involving follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen. At the time of ovulation the fimbria of the oviduct are closely applied to the surface of the ovary. The extruded oocyte and adherent granulosa cells, known as the cumulus oophorus, is collected by the ciliated fimbrial end of the fallopian tube. The transport of the egg into the end of the fallopian tube occurs within minutes and is regulated primarily by ciliary action. The cumulus cells are able to communicate with one another via a network of intercellular bridges through the zona pellucida to the perivitelline space. The cumulus cells have also been reported to play a role in nutrition and maintenance of the ovum. There are three different stages of passage of the ovum through the fallopian tube. The first stage includes the transfer of the ovum from the fimbriated end of the fallopian tube until the egg reaches and is retained at the ampullary-isthmic junction. The ampullary-isthmic junction is a functional block but is not a clearly defined anatomical structure. The ovum remains at this junction for 1–2 days, during which time fertilization occurs.
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Shinde, Jayesh Parasharam. "Assisted Hatching." In Advances in Assisted Reproduction Technologies, 174–94. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815051667122050010.
Повний текст джерелаАнотація:
The selected Spermatozoa when it reaches the ovulated Cumulus Oocyte Complex after ovulation, dispersion of the granulosa cells and corona radiata cells occur. The Spermatozoa then must cross the Zona Pellucida (ZP), fuse with the oolemma, and then subsequently fertilize the oocyte. Embryologist Karl Ernst von Baer coined the term ‘Zona Pellucida’ from Greek work Zone which means belt or girdle and Latin work Pellucida which means transparent or shining. This extracellular matrix is about 13-15 um thick and surrounds all the mammalian eggs and pre-implantation embryos. Zona Pellucida structure is made up of carbohydrates, specific proteins, glycoproteins, hyaluronic acid, heparin, collagen, and fibrous proteins. Human Zona Pellucida contains 4 glycosylated proteins namely ZP1, ZP2, ZP3, and ZP4. ZP plays an important role in helping oocytes to transport essential nutrients and helps in avoiding polyspermy by hardening after fertilization. The embryos must break open the protective ZP layer to the implant, the process is called hatching. It is said that in Assisted reproductive treatment (ART) factors such as the non-availability of enzymes from the endometrium which helps in hatching, extended culture, vitrification may lead to failure in the hatching of embryos from ZP. It was postulated that micromanipulation of ZP to create an opening will help the embryos to hatch and thus implant and will lead to an increase in Implantation rates (IR). This process was later called Assisted Hatching (AH). Various methods were discovered for Assisted hatching such as mechanical ZP AH, zona digestion using enzymes, and laser-Assisted hatching. This chapter will focus on the advantages and disadvantages of each method of AH and their applications in ART along with the impact of AH on clinical outcomes. The use of any method of AH should be chosen carefully to avoid damage to the embryo which will defy the whole purpose of application of AH. In any case, laser-assisted hatching is widely used for Pre- Implantation Genetic Testing (PGT) of the embryos as it is very safe if applied properly, convenient, easy to use, and faster compared to other methods of AH. Each laboratory should identify the correct time and stage at which application of AH is considered based on whether it is helping to improve clinical rates or not.