Embryo

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David K Gardner - One of the best experts on this subject based on the ideXlab platform.

  • addition of ascorbate during cryopreservation stimulates subsequent Embryo development
    Human Reproduction, 2002
    Co-Authors: Michelle Lane, Jeffery M Maybach, David K Gardner
    Abstract:

    BACKGROUND: Embryo development following cryopreservation is reduced compared with fresh Embryos. One of the traumas that cryopreservation imparts on Embryos is an increase in oxidative stress. Therefore, this study investigated the effects of the addition of the antioxidant ascorbate to the cryopreservation solutions on subsequent Embryo development. METHODS: Mouse Embryos at the 2-cell and blastocyst stages were either slow-frozen or vitrified in solutions containing either no ascorbate or 0.1 or 0.5 mmol/l ascorbate. The effects on the levels of hydrogen peroxide and subsequent Embryo development and physiology were assessed. RESULTS: Addition of ascorbate to the cryopreservation solutions reduced the levels of hydrogen peroxide in Embryos. Furthermore, addition of 0.1 mmol/l ascorbate significantly enhanced inner cell mass development in blastocysts. Embryos cryopreserved with ascorbate had significantly lower levels of lactate dehydrogenase leakage, and increased rates of metabolism compared with those cryopreserved in the absence of ascorbate. The benefits of ascorbate were significantly greater in Embryos that were slow-frozen compared with those that were vitrified. CONCLUSIONS: These data indicate that the addition of 0.1 mmol/l ascorbate to the cryopreservation solutions for the mammalian Embryo would be of significant value.

  • noninvasive assessment of human Embryo nutrient consumption as a measure of developmental potential
    Fertility and Sterility, 2000
    Co-Authors: David K Gardner, Michelle Lane, J M Stevens, W B Schoolcraft
    Abstract:

    Abstract Objective: To determine the relationship between blastocyst development and morphology and Embryo metabolism. Design: Noninvasive assessment of carbohydrate uptake and ammonium production by individual Embryos. Setting: Private assisted reproductive technology unit. Patient(s): Patients donated, with consent, cryopreserved pronucleate Embryos and noncryopreserved blastocysts. Intervention(s): Culture of 60 thawed pronucleate Embryos in sequential media to the blastocyst stage with concomitant noninvasive analysis of Embryo metabolism and analysis of 13 blastocysts from noncryopreserved Embryos. Main Outcome Measure(s): Pyruvate and glucose consumption as well as blastocyst formation and quality. Result(s): Pyruvate and glucose uptakes on day 4 were significantly higher by Embryos that went on to form blastocysts than by Embryos that failed to develop to the blastocyst stage. Glucose uptakes were greatest in those blastocysts of highest grade, whereas pyruvate uptakes were similar irrespective of blastocyst grade, indicating that glucose is the more important nutrient for the human blastocyst. Among blastocysts of the same grade from the same patient, there was considerable spread of glucose consumption, indicating that glucose consumption may be of use in identifying blastocysts for transfer. Ammonium production by individual Embryos was also measured, reflecting amino acid transamination and use by the human Embryo. Conclusion(s): The ability to identify in culture the Embryo with the highest developmental potential will facilitate the move to single-Embryo transfers.

Michelle Lane - One of the best experts on this subject based on the ideXlab platform.

  • addition of ascorbate during cryopreservation stimulates subsequent Embryo development
    Human Reproduction, 2002
    Co-Authors: Michelle Lane, Jeffery M Maybach, David K Gardner
    Abstract:

    BACKGROUND: Embryo development following cryopreservation is reduced compared with fresh Embryos. One of the traumas that cryopreservation imparts on Embryos is an increase in oxidative stress. Therefore, this study investigated the effects of the addition of the antioxidant ascorbate to the cryopreservation solutions on subsequent Embryo development. METHODS: Mouse Embryos at the 2-cell and blastocyst stages were either slow-frozen or vitrified in solutions containing either no ascorbate or 0.1 or 0.5 mmol/l ascorbate. The effects on the levels of hydrogen peroxide and subsequent Embryo development and physiology were assessed. RESULTS: Addition of ascorbate to the cryopreservation solutions reduced the levels of hydrogen peroxide in Embryos. Furthermore, addition of 0.1 mmol/l ascorbate significantly enhanced inner cell mass development in blastocysts. Embryos cryopreserved with ascorbate had significantly lower levels of lactate dehydrogenase leakage, and increased rates of metabolism compared with those cryopreserved in the absence of ascorbate. The benefits of ascorbate were significantly greater in Embryos that were slow-frozen compared with those that were vitrified. CONCLUSIONS: These data indicate that the addition of 0.1 mmol/l ascorbate to the cryopreservation solutions for the mammalian Embryo would be of significant value.

  • noninvasive assessment of human Embryo nutrient consumption as a measure of developmental potential
    Fertility and Sterility, 2000
    Co-Authors: David K Gardner, Michelle Lane, J M Stevens, W B Schoolcraft
    Abstract:

    Abstract Objective: To determine the relationship between blastocyst development and morphology and Embryo metabolism. Design: Noninvasive assessment of carbohydrate uptake and ammonium production by individual Embryos. Setting: Private assisted reproductive technology unit. Patient(s): Patients donated, with consent, cryopreserved pronucleate Embryos and noncryopreserved blastocysts. Intervention(s): Culture of 60 thawed pronucleate Embryos in sequential media to the blastocyst stage with concomitant noninvasive analysis of Embryo metabolism and analysis of 13 blastocysts from noncryopreserved Embryos. Main Outcome Measure(s): Pyruvate and glucose consumption as well as blastocyst formation and quality. Result(s): Pyruvate and glucose uptakes on day 4 were significantly higher by Embryos that went on to form blastocysts than by Embryos that failed to develop to the blastocyst stage. Glucose uptakes were greatest in those blastocysts of highest grade, whereas pyruvate uptakes were similar irrespective of blastocyst grade, indicating that glucose is the more important nutrient for the human blastocyst. Among blastocysts of the same grade from the same patient, there was considerable spread of glucose consumption, indicating that glucose consumption may be of use in identifying blastocysts for transfer. Ammonium production by individual Embryos was also measured, reflecting amino acid transamination and use by the human Embryo. Conclusion(s): The ability to identify in culture the Embryo with the highest developmental potential will facilitate the move to single-Embryo transfers.

Jeanfrancois Hausman - One of the best experts on this subject based on the ideXlab platform.

  • comparison between somatic and zygotic Embryo development in quercus robur l
    Plant Biosystems, 2001
    Co-Authors: Magdalena Paladanicolau, Jeanfrancois Hausman
    Abstract:

    ABSTRACT Somatic Embryogenesis from juvenile explants as an efficient way for oak clonal propagation is drastically limited by the low rate of Embryo germination. A comparison of the development of immature somatic and zygotic Embryos, and a study of the changes in sugar content and lignin accumulation during somatic versus zygotic Embryo development were conducted in view of understanding the effect of reserve substance deficiency upon somatic Embryo maturation. A morphological comparison of somatic and zygotic Embryos led to the identification of 4 to 7 similar developmental stages in both types of Embryos, thus indicating that the accumulation phase in both zygotic and somatic Embryos occurs at the same stage, when the cotyledons became thicker and opaque. Carbohydrate analysis showed the presence of glycerol, inositol, mannitol, galactose, trehalose, xylose, arabinose, glucose, fructose and sucrose in all stages of zygotic and somatic Embryo development, but in different amounts. The amount of glycero...

Jorge M Canhoto - One of the best experts on this subject based on the ideXlab platform.

  • somatic Embryogenesis in tamarillo cyphomandra betacea approaches to increase efficiency of Embryo formation and plant development
    Plant Cell Tissue and Organ Culture, 2012
    Co-Authors: Sandra Correia, Ana Estefânia Cunha, Ligia Salgueiro, Jorge M Canhoto
    Abstract:

    Somatic Embryogenesis induction and somatic Embryo development of the solanaceous tamarillo tree were previously established and successfully used for plant regeneration from different explants and varieties. Somatic Embryogenesis was induced in Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) or picloram and high sucrose concentrations (0.25 M). The Embryogenic tissues were transferred to an auxin-free medium, with reduced sucrose levels, to permit Embryo development and conversion into plantlets. This two-step protocol is often impaired by an ineffective transition from the proEmbryogenic masses to Embryo development. In this work, attempts to optimize the somatic Embryogenesis system of tamarillo by improving the quality of somatic Embryo and Embryo conversion were carried out. The results showed that the presence of a high number of abnormal somatic Embryos did not significantly inhibit plant conversion, hence indicating that shoot apical meristem development was not affected in abnormal somatic Embryos. It was also shown that the manipulation of sucrose concentration in the development medium (0.11 M) and dark conditions before conversion increased the number of morphologically normal somatic Embryos. The comparison between mature cotyledonary zygotic and somatic Embryos showed an inefficient accumulation of storage compounds, mainly lipids, in somatic Embryos. These reduced levels of lipid storage could be responsible for the abnormal patterns of Embryo development found in tamarillo somatic Embryos.

  • characterization of somatic Embryo attached structures in feijoa sellowiana berg myrtaceae
    Protoplasma, 2010
    Co-Authors: Sandra M Correia, Jorge M Canhoto
    Abstract:

    The presence of an attached organ to somatic Embryos of angiosperms connecting the Embryo to the supporting tissue has been a subject of controversy. This study shows that 67% of the morphologically normal somatic Embryos of Feijoa sellowiana possess this type of organ and that its formation was not affected by culture media composition. Histological and ultrastructural analysis indicated that the attached structures of somatic Embryos displayed a great morphological diversity ranging from a few cells to massive and columnar structures. This contrast with the simple suspensors observed in zygotic Embryos which were only formed by five cells. As well as the suspensor of zygotic Embryos, somatic Embryo attached structures undergo a process of degeneration in later stages of Embryo development. Other characteristic shared by zygotic suspensors and somatic Embryo attached structures was the presence of thick cell walls surrounding the cells. Elongated thin filaments were often associated with the structures attached to somatic Embryos, whereas in other cases, tubular cells containing starch grains connected the Embryo to the supporting tissue. These characteristics associated with the presence of plasmodesmata in the cells of the attached structures seem to indicate a role on Embryo nutrition. However, cell proliferation in the attached structures resulting into new somatic Embryos may also suggest a more complex relationship between the Embryo and the structures connecting it to the supporting tissue.

Denny Sakkas - One of the best experts on this subject based on the ideXlab platform.

  • noninvasive metabolomic profiling as an adjunct to morphology for noninvasive Embryo assessment in women undergoing single Embryo transfer
    Fertility and Sterility, 2010
    Co-Authors: Emre Seli, O Kato, C G Vergouw, Hiroshi Morita, Lucy Botros, P Roos, C B Lambalk, Naoki Yamashita, Denny Sakkas
    Abstract:

    Objective To determine whether metabolomic profiling of spent Embryo culture media correlates with reproductive potential of human Embryos. Design Retrospective study. Setting Academic and a private assisted reproductive technology (ART) programs. Patient(s) Women undergoing single Embryo transfer after IVF. Intervention(s) Spent Embryo culture media were collected after single Embryo transfer on day 3 (n = 304) or day 2 (n = 181) and analyzed by near infrared spectroscopy. Near infrared spectral regions were correlated to reproductive potential using a genetic algorithm optimization. Models of these spectral regions were used to calculate viability indices, and were validated by blinded analysis of a subset (n = 60) of samples. Implantation rates were also compared between Embryos of higher (≥0.3) and lower ( Main Outcome Measure(s) Viability index and Embryo viability. Result(s) Mean viability indices of Embryos that resulted in positive fetal cardiac activity were significantly higher compared with Embryos that did not for both day 2 and day 3 Embryos. Blinded validation of the day 2 model proved to be significant. Increasing viability index values correlated with an increase in pregnancy. Viability indices were found to be independent of morphology for both day 2 and day 3 Embryos. Implantation rates were significantly higher among Embryos with viability indices ≥0.3. Conclusion(s) Metabolomic profiling of human Embryo culture media using near infrared spectroscopy is independent of morphology and correlates with reproductive potential of Embryos.