The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Alan L. Goldin - One of the best experts on this subject based on the ideXlab platform.
-
Maintenance of Xenopus laevis and Oocyte injection.
Methods in enzymology, 1992Co-Authors: Alan L. GoldinAbstract:Publisher Summary This chapter explains the maintenance of Xenopus laevis and Oocyte injection. There are six species of Xenopus , all indigenous to Africa, but Xenopus laevis is the only one commonly used in laboratory research. To synchronize Oocyte Development, the frogs can be injected with human chorionic gonadotropin (hCG), which induces ovulation and egg laying, after which Oocyte Development starts over approximately synchronously. Xenopus can tolerate a wide range of temperature fluctuations, but the quality of Oocytes diminishes markedly following temperature shifts. Therefore, frogs should be housed in a temperature-controlled environment. Xenopus are very susceptible to desiccation, and they can die from being out of the water for a few hours. Oocytes from Xenopus laevis can be classified into six stages of Development on the basis of anatomy; the choice of which stage Oocytes to inject depends on the purposes of the experiment.
Qiang Wang - One of the best experts on this subject based on the ideXlab platform.
-
Mitofusin1 in Oocyte is essential for female fertility
Redox biology, 2019Co-Authors: Xiaojing Hou, Shuai Zhu, Hao Zhang, Danhong Qiu, Xuejiang Guo, Qiang WangAbstract:Mitofusins (Mfn) are the important regulators of mitochondrial organization in mammalian cells; however, their roles during Oocyte Development remain unknown. In the present study, we generated mice with Oocyte-specific knockout of Mfn1 or Mfn2 (Mfn1fl/fl;Zp3-Cre or Mfn2fl/fl;Zp3-Cre). We report that deletion of Mfn1, but not Mfn2, in Oocytes leads to female mice sterility, associated with the defective folliculogenesis and impaired Oocyte quality. In specific, follicles are arrested at secondary stage in Mfn1fl/fl;Zp3-Cre mice, accompanying with the reduced proliferation of granulosa cells. Moreover, alterations of mitochondrial structure and distribution pattern are readily observed in Mfn1-null Oocytes. Consistent with this, mitochondrial activity and function are severely disrupted in Oocytes from Mfn1fl/fl;Zp3-Cre mice. In addition, the differentially expressed genes in Mfn1-deleted Oocytes are also identified by whole-transcriptome sequencing. In sum, these results demonstrate that Mfn1-modulated mitochondrial function is essential for Oocyte Development and folliculogenesis, providing a novel mechanism determining female fertility.
-
Mitofusin1 in Oocyte is essential for female fertility
Elsevier, 2019Co-Authors: Xiaojing Hou, Shuai Zhu, Hao Zhang, Danhong Qiu, Xuejiang Guo, Qiang WangAbstract:Mitofusins (Mfn) are the important regulators of mitochondrial organization in mammalian cells; however, their roles during Oocyte Development remain unknown. In the present study, we generated mice with Oocyte-specific knockout of Mfn1 or Mfn2 (Mfn1fl/fl;Zp3-Cre or Mfn2fl/fl;Zp3-Cre). We report that deletion of Mfn1, but not Mfn2, in Oocytes leads to female mice sterility, associated with the defective folliculogenesis and impaired Oocyte quality. In specific, follicles are arrested at secondary stage in Mfn1fl/fl;Zp3-Cre mice, accompanying with the reduced proliferation of granulosa cells. Moreover, alterations of mitochondrial structure and distribution pattern are readily observed in Mfn1-null Oocytes. Consistent with this, mitochondrial activity and function are severely disrupted in Oocytes from Mfn1fl/fl;Zp3-Cre mice. In addition, the differentially expressed genes in Mfn1-deleted Oocytes are also identified by whole-transcriptome sequencing. In sum, these results demonstrate that Mfn1-modulated mitochondrial function is essential for Oocyte Development and folliculogenesis, providing a novel mechanism determining female fertility. Keywords: Mitochondria, Folliculogenesis, Oocyte, Fertility, Reproductio
-
metabolic control of Oocyte Development linking maternal nutrition and reproductive outcomes
Cellular and Molecular Life Sciences, 2015Co-Authors: Honglin Liu, Christina E Boots, Kelle H Moley, Qiang WangAbstract:Obesity, diabetes, and related metabolic disorders are major health issues worldwide. As the epidemic of metabolic disorders continues, the associated medical co-morbidities, including the detrimental impact on reproduction, increase as well. Emerging evidence suggests that the effects of maternal nutrition on reproductive outcomes are likely to be mediated, at least in part, by Oocyte metabolism. Well-balanced and timed energy metabolism is critical for optimal Development of Oocytes. To date, much of our understanding of Oocyte metabolism comes from the effects of extrinsic nutrients on Oocyte maturation. In contrast, intrinsic regulation of Oocyte Development by metabolic enzymes, intracellular mediators, and transport systems is less characterized. Specifically, decreased acid transport proteins levels, increased glucose/lipid content and elevated reactive oxygen species in Oocytes have been implicated in meiotic defects, organelle dysfunction and epigenetic alteration. Therefore, metabolic disturbances in Oocytes may contribute to the diminished reproductive potential experienced by women with metabolic disorders. In-depth research is needed to further explore the underlying mechanisms. This review also discusses several approaches for metabolic analysis. Metabolomic profiling of Oocytes, the surrounding granulosa cells, and follicular fluid will uncover the metabolic networks regulating Oocyte Development, potentially leading to the identification of Oocyte quality markers and prevention of reproductive disease and poor outcomes in offspring.
Evelyn E Telfer - One of the best experts on this subject based on the ideXlab platform.
-
future Developments in vitro growth ivg of human ovarian follicles
Acta Obstetricia et Gynecologica Scandinavica, 2019Co-Authors: Evelyn E TelferAbstract:Removal and storage of ovarian cortical tissue is currently offered to young female cancer patients undergoing potentially sterilizing chemotherapy and/or radiotherapy. For patients at high risk of reintroduction of malignancy through auto-transplantation, the ultimate aim is to achieve complete Oocyte Development from this tissue in vitro. The ability to develop human Oocytes from the earliest follicular stages through to maturation and fertilization in vitro would revolutionize fertility preservation practice. This has been achieved in mice where in vitro grown Oocytes from primordial follicles have resulted in the production of live offspring. Systems that support growth and Development of Oocytes from human ovarian cortex are being developed by several groups. This review focuses on the steps required to recapitulate in vitro the process of human Oocyte Development from the primordial stage and the systems currently available to support this.
-
ovarian follicle culture advances and challenges for human and nonhuman primates
Fertility and Sterility, 2013Co-Authors: Evelyn E Telfer, Mary B ZelinskiAbstract:The removal and cryostorage of ovarian cortical biopsies is now offered as a fertility preservation option for young women. The only available option to restore fertility using this tissue is by transplantation, which may not be possible for all patients. The full potential of this tissue to restore fertility could be achieved by the Development of in vitro systems that support Oocyte Development from the most immature stages to maturation. The techniques of in vitro growth (IVG) combined with in vitro maturation (IVM) are being developed with human tissue, but comparing different systems has been difficult because of the scarcity of tissue so nonhuman primates are being used as model systems. There are many challenges to developing a complete culture system that would support human Oocyte Development, and this review outlines the approaches being taken by several groups using tissue from women and nonhuman primate models to support each of the stages of Oocyte Development.
-
strategies to support human Oocyte Development in vitro
The International Journal of Developmental Biology, 2012Co-Authors: Evelyn E Telfer, Marie MclaughlinAbstract:Many young cancer patients are now being given the option to store ovarian cortical biopsies before undergoing potentially damaging chemo or radio-therapy. This tissue mainly contains large numbers of immature primordial follicles. Currently the only option to restore fertility using this tissue is by transplantation which may not be a viable option for all patients. Greater options to realise the potential of this tissue to restore fertility could be achieved by the Development of in vitro systems that support Oocyte Development. The ability to develop human Oocytes from the most immature stages of follicles (primordial) through to maturation and fertilisation in vitro would revolutionise fertility preservation practice. This has been achieved in mouse where in vitro grown (IVG) Oocytes from primordial follicles have resulted in the production of live offspring. However, developing IVG systems to support complete Development of human Oocytes has been more difficult because of differences in scale of timing and size. Our lab has been working on a multi-step culture system to support growth and Development of bo-vine and human Oocytes from primordial through to fully grown, using fresh and cryopreserved ovarian cortical tissue. This review outlines the approaches being taken to obtain complete in vitro Development of human Oocytes and strategies for assessing the health and viability of IVG Oocytes.
-
Oocyte Development in bovine primordial follicles is promoted by activin and fsh within a two step serum free culture system
Reproduction, 2010Co-Authors: Marie Mclaughlin, Evelyn E TelferAbstract:Quiescent follicles of large mammals initiate growth within cultured pieces of ovarian cortex. Systems capable of sustaining in vitro Development from this early stage until Oocyte maturation would allow investigation of mechanisms regulating Oocyte Development in its entirety. The aims of this study were 1) to determine whether bovine follicles initiated to grow in vitro could be isolated from the cortical environment, and could undergo further Development and 2) to evaluate the effect of activin and FSH on the Development of secondary follicles derived from primordial follicles. Fragments of bovine ovarian cortex were cultured in serum-free medium for 6 days; thereafter, secondary follicles were isolated for further culture. After a maximum total of 21 days in vitro, follicles were either processed for histological assessment or opened to release the Oocyte-cumulus complexes for inspection by light microscopy. Compared with control, significant follicle and Oocyte growth were observed in activin-exposed follicles, with or without FSH, with some Oocyte diameters measuring over 100 microns following a total in vitro period of 15 days. Significant oestradiol secretion was observed in follicles cultured in activin alone after a total of 9 days in vitro compared with other treatment groups; however, this effect was not sustained. In summary, this study demonstrates the promotion of primordial bovine follicle Development within a two-step serum-free culture system with Oocyte diameters >100 mum achieved over 15 days in vitro. Further Development of this system is needed to support complete Oocyte growth and thereafter in vitro maturation.
Irani Quagio-grassiotto - One of the best experts on this subject based on the ideXlab platform.
-
A cytochemical approach to describe Oocyte Development in the freshwater ostariophysan, Serrasalmus maculatus (Characiformes).
Micron (Oxford England : 1993), 2014Co-Authors: Irani Quagio-grassiotto, Daniel Dantas Wildner, Ariene Cristina Dias Guimarães-bassoliAbstract:With the intent to provide additional information on the reproductive biology of the ostariophysian fish, the Oocyte Development in Serrasalmus maculatus is here described under light and electron microscopy by using some cytochemical methods. Our results are discussed considering the cellular processes that drive the Oocyte Development and comparing to the available information on other groups of fish. Despite the Oocyte Development to be in general a conserved process, some characteristics of the Oocytes of this species come to light. Possibly related to the reproductive strategy of S. maculatus are the absence of oil droplets and the presence of well-developed cortical alveoli. Besides this finding, our results suggest the presence of high content of basic residues in yolk proteins, the presence of acidic polysaccharides in the zona pellucida and a possible involvement of the follicular cells in the steroidogenesis process.
-
Female germ cell renewal during the annual reproductive cycle in Ostariophysians fish
Theriogenology, 2013Co-Authors: Daniel Dantas Wildner, Harry J. Grier, Irani Quagio-grassiottoAbstract:The objective was to characterize female germ cell renewal during the annual reproductive cycle in two species of ostariophysian fish with distinct reproductive strategies: a siluriform, Pimelodus maculatus, in which Oocyte Development is group synchronous and the annual reproductive period is short; and a characiform, Serrasalmus maculatus, with asynchronous Oocyte Development and a prolonged reproductive period. These reproductive strategies result in fish determinate and indeterminate fecundity, respectively. Annual reproductive phases were determined by biometric and histologic analysis of gonads and interpreted according to new proposals for phase classification and stages of Oocyte Development (with special attention to germinal epithelium activity). Histologically, there were two types of oogonia in the germinal epithelium: single oogonia and those in mitotic proliferation. Oogonial proliferation and their entry into meiosis resulted in formation of cell nests (clusters of cells in the ovarian lamellae). Morphometric analysis was used to estimate germ cell renewal. Based on numbers of single oogonia in the lamellar epithelium, and nests with proliferating oogonia or early prophase Oocytes throughout the annual reproductive cycle, oogonial proliferation and entrance into meiosis were more intense during the regenerating phase and developing phase, but decreased sharply (P < 0.05) during the spawning-capable phase. Oogonial proliferation gradually recovered during the regressing phase. We concluded that, independent of species or features of the reproductive cycle, germ cell renewal occurred during the regenerating phase, ensuring availability of eggs for the spawning event.
Marie Mclaughlin - One of the best experts on this subject based on the ideXlab platform.
-
strategies to support human Oocyte Development in vitro
The International Journal of Developmental Biology, 2012Co-Authors: Evelyn E Telfer, Marie MclaughlinAbstract:Many young cancer patients are now being given the option to store ovarian cortical biopsies before undergoing potentially damaging chemo or radio-therapy. This tissue mainly contains large numbers of immature primordial follicles. Currently the only option to restore fertility using this tissue is by transplantation which may not be a viable option for all patients. Greater options to realise the potential of this tissue to restore fertility could be achieved by the Development of in vitro systems that support Oocyte Development. The ability to develop human Oocytes from the most immature stages of follicles (primordial) through to maturation and fertilisation in vitro would revolutionise fertility preservation practice. This has been achieved in mouse where in vitro grown (IVG) Oocytes from primordial follicles have resulted in the production of live offspring. However, developing IVG systems to support complete Development of human Oocytes has been more difficult because of differences in scale of timing and size. Our lab has been working on a multi-step culture system to support growth and Development of bo-vine and human Oocytes from primordial through to fully grown, using fresh and cryopreserved ovarian cortical tissue. This review outlines the approaches being taken to obtain complete in vitro Development of human Oocytes and strategies for assessing the health and viability of IVG Oocytes.
-
Oocyte Development in bovine primordial follicles is promoted by activin and fsh within a two step serum free culture system
Reproduction, 2010Co-Authors: Marie Mclaughlin, Evelyn E TelferAbstract:Quiescent follicles of large mammals initiate growth within cultured pieces of ovarian cortex. Systems capable of sustaining in vitro Development from this early stage until Oocyte maturation would allow investigation of mechanisms regulating Oocyte Development in its entirety. The aims of this study were 1) to determine whether bovine follicles initiated to grow in vitro could be isolated from the cortical environment, and could undergo further Development and 2) to evaluate the effect of activin and FSH on the Development of secondary follicles derived from primordial follicles. Fragments of bovine ovarian cortex were cultured in serum-free medium for 6 days; thereafter, secondary follicles were isolated for further culture. After a maximum total of 21 days in vitro, follicles were either processed for histological assessment or opened to release the Oocyte-cumulus complexes for inspection by light microscopy. Compared with control, significant follicle and Oocyte growth were observed in activin-exposed follicles, with or without FSH, with some Oocyte diameters measuring over 100 microns following a total in vitro period of 15 days. Significant oestradiol secretion was observed in follicles cultured in activin alone after a total of 9 days in vitro compared with other treatment groups; however, this effect was not sustained. In summary, this study demonstrates the promotion of primordial bovine follicle Development within a two-step serum-free culture system with Oocyte diameters >100 mum achieved over 15 days in vitro. Further Development of this system is needed to support complete Oocyte growth and thereafter in vitro maturation.
