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Seiji Ohsumi - One of the best experts on this subject based on the ideXlab platform.
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developmental capacity of antarctic mInke whale balaenoptera bonaerensis vitrified oocytes followIng In Vitro Maturation and parthenogenetic activation or Intracytoplasmic sperm Injection
Zygote, 2006Co-Authors: Takuma Fujihira, Hajime Ishikawa, Seiji Ohsumi, Mariko Kobayashi, Shinichi Hochi, Masumi Hirabayashi, Yutaka FukuiAbstract:The present study Investigated the effects of the sexual maturity of oocyte donors on In Vitro Maturation (IVM) and the parthenogenetic developmental capacity of fresh mInke whale oocytes. The effects of cytochalasIn B (CB) pretreatment and two types of cryoprotectant solutions (ethylene glycol (EG) or ethylene glycol and dimethylsulfoxide (EG + DMSO)) on the In Vitro Maturation of vitrified immature whale oocytes were compared, and the developmental capacity of vitrified immature whale oocytes followIng IVM and Intracytoplasmic sperm Injection examIned (ICSI). The Maturation rate did not differ significantly with sexual maturity (adult, 60.9%; prepubertal, 53.1%), but the parthenogenetic activation rate of oocytes from adult donors (76.7%) was significantly higher (p < 0.05) than that of oocytes from prepubertal donors (46.4%). The Maturation rates after vitrification and warmIng were not significantly different between the EG (22.2%) and EG + DMSO groups (30.2%), or between the CB-treated (30.4%) and non-CB-treated groups (27.3%). These results Indicate that parthenogenetic activation of In Vitro matured oocytes from adult mInke whales was superior to that from prepubertal whales, but that the developmental capacity of the whale oocytes after parthenogenetic activation or ICSI was still low. The present study also showed that CB treatment before vitrification and two kInds of cryoprotectants did not improve the IVM rate followIng the vitrification of immature whale oocytes.
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attempt at In Vitro Maturation of mInke whale balaenoptera bonaerensis oocytes usIng a portable co2 Incubator
Journal of Reproduction and Development, 2005Co-Authors: Hiroshi Iwayama, Hajime Ishikawa, Seiji Ohsumi, Yutaka FukuiAbstract:The present study was conducted to Investigate whether a portable CO2 Incubator was effective for In Vitro Maturation (IVM) of bovIne, porcIne and mInke whale oocytes, and the effect of Maturation media supplemented with different hormones; porcIne follicle stimulatIng hormone (pFSH), estradiol-17β (E2), or pregnant mare's serum gonadotropIn (PMSG): human chorionic gonadotropIn (hCG) for mInke whale immature oocytes was also examIned. In Vitro Maturation rates of bovIne and porcIne oocytes cultured In the portable CO2 Incubator were not significantly different from the standard CO2 Incubator. In mInke whale IVM culture usIng the portable Incubator, the maximum expansion of cumulus mass was observed by pFSH/E2 and PMSG/hCG at the end of IVM culture. Moreover, the IVM culture period was shortened to 28-30 h from 96-120 h previously reported. The proportion of matured oocytes cultured In the medium supplemented with pFSH/E2 (26.7%) was significantly higher (P<0.05) than that with PMSG/hCG (6.9%). The present study Indicates that a portable CO2 Incubator is a useful device for mInke whale IVM culture on a research base ship, and the addition of pFSH/E2 Into an IVM medium enhanced cumulus expansion and the proportion of mInke whale matured oocytes.
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In Vitro Maturation and ultrastructural observation of cryopreserved mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 2000Co-Authors: Masatsugu Asada, Hajime Ishikawa, Yutaka Fukui, Toshihiro Mogoe, Miki Horii, Seiji OhsumiAbstract:MInke whale (Balaenoptera acutorostrata) follicular oocytes were cryopreserved by a slow-step freezIng procedure usIng ethylene glycol. The morphologically viable proportion of postthawed mInke whale follicular oocytes was 39.7%. The maturity of the animals (immature and mature whales) or the presence or absence of cumulus cells (CC) did not affect the proportion of morphologically viable oocytes. Postthawed oocytes were examIned for nuclear status after In Vitro Maturation. The presence of CC (29.1%) significantly enhanced (P < 0.05) the proportion of oocytes at metaphase I/anaphase I/telophase I stages compared to results with the absence of CC (13.5%). A total of 4 of 194 postthawed oocytes matured to the second metaphase stage after culture for 5.5 days with or without CC. The cryopreserved immature oocytes obtaIned from immature and mature whales were processed to examIne the ultrastructure by transmission electron microscopy. VaryIng ultrastructural damage to the cytoplasm was observed as a result of the cryopreservation procedures. These results show that 20-30% of cryopreserved mInke whale follicular oocytes can resume meiosis In Vitro, but damage Induced by the freezIng and thawIng procedures was observed.
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factors affectIng In Vitro Maturation of mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 1997Co-Authors: Yutaka Fukui, Hajime Ishikawa, Toshihiro Mogoe, Seiji OhsumiAbstract:Factors affectIng In Vitro Maturation (IVM) of mInke whale (Balaenopetra acutorostrata) follicular oocytes were Investigated. In experiment 1, recovery rates for oocytes from follicles of different sizes (small, 1-5 mm; medium, 6-10 mm; large, > or = 11 mm) were similar In both immature (54.7%) and mature (53.5%) females, and the follicular sizes did not affect recovery rate. Approximately half the oocytes recovered from small follicles In immature (55.5%) and mature (52.1%) whales were surrounded by at least a few layers of cumulus cells. Before culture, 71.7% and 61.2% of oocytes from immature and mature whales, respectively, were at the germInal vesicle stage. For IVM, effects of serum type, hormones, and additional cumulus cells (experiment 2) and effects of culture durations (24-120 h, experiment 3) were Investigated. The three factors Investigated In experiment 2 did not affect Maturation rates. TCM199 supplemented with fetal whale serum, hormones, and additional cumulus cells showed the highest rate (21.6%) of matured oocytes and resulted In a significant difference from the rate In medium with only fetal calf serum added (6.6%). The first oocyte with an extruded polar body was observed after 84 h of culture. The maximum rate (27.3%) of matured oocytes was obtaIned by 96 h of culture, but there was no significant difference In the proportions of matured oocytes between 90 and 120 h In culture. These results Indicate that In Vitro nuclear Maturation of immature follicular oocytes In mInke whales can be Induced.
Yutaka Fukui - One of the best experts on this subject based on the ideXlab platform.
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developmental capacity of antarctic mInke whale balaenoptera bonaerensis vitrified oocytes followIng In Vitro Maturation and parthenogenetic activation or Intracytoplasmic sperm Injection
Zygote, 2006Co-Authors: Takuma Fujihira, Hajime Ishikawa, Seiji Ohsumi, Mariko Kobayashi, Shinichi Hochi, Masumi Hirabayashi, Yutaka FukuiAbstract:The present study Investigated the effects of the sexual maturity of oocyte donors on In Vitro Maturation (IVM) and the parthenogenetic developmental capacity of fresh mInke whale oocytes. The effects of cytochalasIn B (CB) pretreatment and two types of cryoprotectant solutions (ethylene glycol (EG) or ethylene glycol and dimethylsulfoxide (EG + DMSO)) on the In Vitro Maturation of vitrified immature whale oocytes were compared, and the developmental capacity of vitrified immature whale oocytes followIng IVM and Intracytoplasmic sperm Injection examIned (ICSI). The Maturation rate did not differ significantly with sexual maturity (adult, 60.9%; prepubertal, 53.1%), but the parthenogenetic activation rate of oocytes from adult donors (76.7%) was significantly higher (p < 0.05) than that of oocytes from prepubertal donors (46.4%). The Maturation rates after vitrification and warmIng were not significantly different between the EG (22.2%) and EG + DMSO groups (30.2%), or between the CB-treated (30.4%) and non-CB-treated groups (27.3%). These results Indicate that parthenogenetic activation of In Vitro matured oocytes from adult mInke whales was superior to that from prepubertal whales, but that the developmental capacity of the whale oocytes after parthenogenetic activation or ICSI was still low. The present study also showed that CB treatment before vitrification and two kInds of cryoprotectants did not improve the IVM rate followIng the vitrification of immature whale oocytes.
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attempt at In Vitro Maturation of mInke whale balaenoptera bonaerensis oocytes usIng a portable co2 Incubator
Journal of Reproduction and Development, 2005Co-Authors: Hiroshi Iwayama, Hajime Ishikawa, Seiji Ohsumi, Yutaka FukuiAbstract:The present study was conducted to Investigate whether a portable CO2 Incubator was effective for In Vitro Maturation (IVM) of bovIne, porcIne and mInke whale oocytes, and the effect of Maturation media supplemented with different hormones; porcIne follicle stimulatIng hormone (pFSH), estradiol-17β (E2), or pregnant mare's serum gonadotropIn (PMSG): human chorionic gonadotropIn (hCG) for mInke whale immature oocytes was also examIned. In Vitro Maturation rates of bovIne and porcIne oocytes cultured In the portable CO2 Incubator were not significantly different from the standard CO2 Incubator. In mInke whale IVM culture usIng the portable Incubator, the maximum expansion of cumulus mass was observed by pFSH/E2 and PMSG/hCG at the end of IVM culture. Moreover, the IVM culture period was shortened to 28-30 h from 96-120 h previously reported. The proportion of matured oocytes cultured In the medium supplemented with pFSH/E2 (26.7%) was significantly higher (P<0.05) than that with PMSG/hCG (6.9%). The present study Indicates that a portable CO2 Incubator is a useful device for mInke whale IVM culture on a research base ship, and the addition of pFSH/E2 Into an IVM medium enhanced cumulus expansion and the proportion of mInke whale matured oocytes.
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In Vitro Maturation and ultrastructural observation of cryopreserved mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 2000Co-Authors: Masatsugu Asada, Hajime Ishikawa, Yutaka Fukui, Toshihiro Mogoe, Miki Horii, Seiji OhsumiAbstract:MInke whale (Balaenoptera acutorostrata) follicular oocytes were cryopreserved by a slow-step freezIng procedure usIng ethylene glycol. The morphologically viable proportion of postthawed mInke whale follicular oocytes was 39.7%. The maturity of the animals (immature and mature whales) or the presence or absence of cumulus cells (CC) did not affect the proportion of morphologically viable oocytes. Postthawed oocytes were examIned for nuclear status after In Vitro Maturation. The presence of CC (29.1%) significantly enhanced (P < 0.05) the proportion of oocytes at metaphase I/anaphase I/telophase I stages compared to results with the absence of CC (13.5%). A total of 4 of 194 postthawed oocytes matured to the second metaphase stage after culture for 5.5 days with or without CC. The cryopreserved immature oocytes obtaIned from immature and mature whales were processed to examIne the ultrastructure by transmission electron microscopy. VaryIng ultrastructural damage to the cytoplasm was observed as a result of the cryopreservation procedures. These results show that 20-30% of cryopreserved mInke whale follicular oocytes can resume meiosis In Vitro, but damage Induced by the freezIng and thawIng procedures was observed.
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factors affectIng In Vitro Maturation of mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 1997Co-Authors: Yutaka Fukui, Hajime Ishikawa, Toshihiro Mogoe, Seiji OhsumiAbstract:Factors affectIng In Vitro Maturation (IVM) of mInke whale (Balaenopetra acutorostrata) follicular oocytes were Investigated. In experiment 1, recovery rates for oocytes from follicles of different sizes (small, 1-5 mm; medium, 6-10 mm; large, > or = 11 mm) were similar In both immature (54.7%) and mature (53.5%) females, and the follicular sizes did not affect recovery rate. Approximately half the oocytes recovered from small follicles In immature (55.5%) and mature (52.1%) whales were surrounded by at least a few layers of cumulus cells. Before culture, 71.7% and 61.2% of oocytes from immature and mature whales, respectively, were at the germInal vesicle stage. For IVM, effects of serum type, hormones, and additional cumulus cells (experiment 2) and effects of culture durations (24-120 h, experiment 3) were Investigated. The three factors Investigated In experiment 2 did not affect Maturation rates. TCM199 supplemented with fetal whale serum, hormones, and additional cumulus cells showed the highest rate (21.6%) of matured oocytes and resulted In a significant difference from the rate In medium with only fetal calf serum added (6.6%). The first oocyte with an extruded polar body was observed after 84 h of culture. The maximum rate (27.3%) of matured oocytes was obtaIned by 96 h of culture, but there was no significant difference In the proportions of matured oocytes between 90 and 120 h In culture. These results Indicate that In Vitro nuclear Maturation of immature follicular oocytes In mInke whales can be Induced.
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parthenogenetic development of bovIne oocytes treated with ethanol and cytochalasIn b after In Vitro Maturation
Molecular Reproduction and Development, 1992Co-Authors: Yutaka Fukui, Ken Sawai, Makoto Furudate, Noriyuki Sato, Yasuaki Iwazumi, Kazue OhsakiAbstract:The present study was conducted to Investigate the effects of different culture durations (24–36 hr) on bovIne oocyte Maturation In Vitro and the effect of the presence or absence of cumulus cells at the time of treatment to Induce parthenogenetic activation (exposure to ethanol and cytochalasIn B; CB) (experiment I). The effects of dosage (2.5 or 5.0 μg/ml) and Incubation time (2.5, 5, or 10 hr) In CB (experiment II) on the subsequent development to the blastocyst stage In Vitro was also Investigated. In experiment I, cleavage and development to the blastocyst stage were not affected by the presence or absence of cumulus cells at the time of parthenogenetic activation. However, the 24-hr culture duration for In Vitro Maturation had a significantly lower rate of development to the blastocyst stage than the longer culture durations (27-36 hr). In experiment II, treatment with 5 μg/ml CB for 5 hr showed the highest percentage of development to blastocyst In the oocytes matured for both 27 and 30 hr. To determIne the viability of the parthenogenetic embryos (morulae and blastocysts), four recipient heifers received two embryos each, and one heifer was found to be pregnant on day 35 followIng transfer. Although fetal heartbeat was not observed, the subsequent estrus was prolonged In all heifers. The present results demonstrate development of In Vitro-matured, parthenogenetically activated bovIne embryos up to the preimplantation stage. © 1992 Wiley-Liss, Inc.
Richeng Chian - One of the best experts on this subject based on the ideXlab platform.
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development of In Vitro Maturation techniques for clInical applications
Fertility and Sterility, 2017Co-Authors: Zhiyong Yang, Richeng ChianAbstract:In Vitro Maturation (IVM) refers to Maturation In culture of immature oocytes at different stages that may or may not have been exposed to short courses of gonadotropIns. The source of immature oocytes is an important feature for subsequent embryonic development, pregnancy, and healthy live births. IVM is an effective treatment that has already achieved significant outcomes of acceptable pregnancy and implantation rates and has led to the births of several thousand healthy babies. As the development of IVM treatment contInues, an attractive possibility for improvIng the already successful outcome is to combIne a natural-cycle In Vitro fertilization (IVF) treatment with immature-oocyte retrieval followed by IVM of those immature oocytes. If the treatment processes can be simplified for immature-oocyte retrieval, different types of Infertile women may be able to take advantage of these treatments. Mild-stimulation IVF combIned with IVM treatment may represent a viable alternative to the standard treatment. Although IVM treatment is still considered to be experimental, it is now time to reconsider the IVM technology and its development. Mild-stimulation IVF combIned with IVM may prove to be not just alternatives to standard treatments, but potentially first-lIne treatment choices.
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In Vitro Maturation of human immature oocytes for fertility preservation
Fertility and Sterility, 2013Co-Authors: Richeng Chian, Peter S Uzelac, Geeta NargundAbstract:Cryopreservation of embryos, oocytes, or ovarian tissues is the maIn option for female fertility preservation. Oocyte cryopreservation has emerged as especially important: the dramatic Increase In the number of Infants born from vitrified oocytes Indicates that it is becomIng one of the most important Intervention options. However, oocyte cryopreservation with standard controlled ovarian hyperstimulation may not be feasible for some cancer patients as there are serious concerns about the effect of ovarian stimulation with hormones on the risk of cancer recurrence. Also, urgent gonadotoxic cancer treatment may not allow sufficient time for a patient to undergo hormonal ovarian stimulation. Thus, immature oocyte retrieval from ovaries without ovarian stimulation followed by In Vitro Maturation and vitrification is a promisIng fertility preservation option for women who cannot undergo ovarian stimulation or cannot delay their gonadotoxic cancer treatment. Immature oocytes can be collected from the ovaries durIng both the follicular and luteal phases, which maximizes the possibility for fertility preservation. The combInation of ovarian tissue cryopreservation with immature oocyte collection from the tissue followed by oocyte vitrification via In Vitro Maturation represents another promisIng approach of fertility preservation In young women with cancer.
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In Vitro Maturation of germInal vesicle oocytes recovered after premature luteInizIng hormone surge description of a novel approach to fertility preservation
Fertility and Sterility, 2008Co-Authors: Kutluk Oktay, Richeng Chian, Ezgi Demirtas, Weonyoung Son, Kathy Lostritto, Seang Lin TanAbstract:Objective To report a novel approach to fertility preservation by In Vitro Maturation and embryo cryopreservation after LH surge and ovulation. Design Case report. SettIng Two university-based reproductive endocrInology clInics. Patient(s) Forty-year-old woman with breast cancer seekIng fertility preservation before chemotherapy. Intervention(s) The plan was ovarian stimulation and retrieval of mature oocytes, followed by IVF; however, premature LH surge and ovulation occurred before oocyte retrieval. Because no mature oocyte was recovered, follicles MaIn Outcome Measure(s) Recovery of immature oocytes after ovulation, In Vitro Maturation of these oocytes, and fertilization and vitrification of generated embryos. Result(s) Four immature oocytes were recovered, and two matured In Vitro. After fertilization with Intracytoplasmic sperm Injection, embryos progressed to the four-cell stage on day 2 and were vitrified for future use. Conclusion(s) This case illustrates that under time constraInts, immature oocytes can be recovered after ovulation and used to generate embryos for fertility preservation.
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obstetric outcomes and congenital abnormalities after In Vitro Maturation In Vitro fertilization and Intracytoplasmic sperm Injection
Obstetrics & Gynecology, 2007Co-Authors: William Buckett, Hananel Holzer, Richeng Chian, Nicola Dean, Robert H Usher, Seang Lin TanAbstract:OBJECTIVE:To compare obstetric outcome and congenital abnormalities In pregnancies conceived after In Vitro Maturation (IVM), In Vitro fertilization (IVF), and Intracytoplasmic sperm Injection (ICSI) with those In spontaneously conceived controls.METHODS:Data were collected from the McGill Obstetric
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In Vitro Maturation of oocytes collected from unstimulated ovaries for oocyte donation
Fertility and Sterility, 2007Co-Authors: Hananel Holzer, Eleanor Scharf, Richeng Chian, Ezgi Demirtas, William BuckettAbstract:Objective To assess the role of immature oocyte collection from unstimulated ovaries as a potential source of oocyte donation. Design Prospective cohort study. SettIng A tertiary, university-based, In Vitro fertilization center. Patient(s) Twelve oocyte donors with ultrasound-only polycystic ovaries or polycystic ovary syndrome matched with 12 oocyte recipients. Intervention(s) Immature oocyte collection without any ovarian stimulation. In Vitro Maturation of the oocytes. Embryo transfer of the embryos. MaIn Outcome Measure(s) Immature oocyte collection, Maturation, fertilization, and cleavage rates. Implantation, pregnancy, and live birth rates. Result(s) A mean of 12.8 ± 5.1 GermInal-vesicle oocytes were aspirated per collection. The In Vitro Maturation rate was 68.3% ± 18.4% with a mean of 8.7 ± 3.6 mature oocytes per collection. The mean fertilization rate was 73.3% ± 19.4%. Two to five embryos (median four) were transferred. Six recipients conceived, givIng a 50% clInical pregnancy rate per cycle. The mean implantation rate per embryo was 18.2%. The live birth rate per cycle started was 30%. Conclusion(s) CollectIng immature oocytes from unstimulated ovaries for the purpose of oocyte donation is a simple procedure that totally avoids ovarian stimulation. With appropriate selection of women with ultrasound-only polycystic ovaries or women with the polycystic ovary syndrome, the pregnancy rates of the recipients are comparable with those achieved through conventional IVF oocyte donor cycles.
Hajime Ishikawa - One of the best experts on this subject based on the ideXlab platform.
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developmental capacity of antarctic mInke whale balaenoptera bonaerensis vitrified oocytes followIng In Vitro Maturation and parthenogenetic activation or Intracytoplasmic sperm Injection
Zygote, 2006Co-Authors: Takuma Fujihira, Hajime Ishikawa, Seiji Ohsumi, Mariko Kobayashi, Shinichi Hochi, Masumi Hirabayashi, Yutaka FukuiAbstract:The present study Investigated the effects of the sexual maturity of oocyte donors on In Vitro Maturation (IVM) and the parthenogenetic developmental capacity of fresh mInke whale oocytes. The effects of cytochalasIn B (CB) pretreatment and two types of cryoprotectant solutions (ethylene glycol (EG) or ethylene glycol and dimethylsulfoxide (EG + DMSO)) on the In Vitro Maturation of vitrified immature whale oocytes were compared, and the developmental capacity of vitrified immature whale oocytes followIng IVM and Intracytoplasmic sperm Injection examIned (ICSI). The Maturation rate did not differ significantly with sexual maturity (adult, 60.9%; prepubertal, 53.1%), but the parthenogenetic activation rate of oocytes from adult donors (76.7%) was significantly higher (p < 0.05) than that of oocytes from prepubertal donors (46.4%). The Maturation rates after vitrification and warmIng were not significantly different between the EG (22.2%) and EG + DMSO groups (30.2%), or between the CB-treated (30.4%) and non-CB-treated groups (27.3%). These results Indicate that parthenogenetic activation of In Vitro matured oocytes from adult mInke whales was superior to that from prepubertal whales, but that the developmental capacity of the whale oocytes after parthenogenetic activation or ICSI was still low. The present study also showed that CB treatment before vitrification and two kInds of cryoprotectants did not improve the IVM rate followIng the vitrification of immature whale oocytes.
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attempt at In Vitro Maturation of mInke whale balaenoptera bonaerensis oocytes usIng a portable co2 Incubator
Journal of Reproduction and Development, 2005Co-Authors: Hiroshi Iwayama, Hajime Ishikawa, Seiji Ohsumi, Yutaka FukuiAbstract:The present study was conducted to Investigate whether a portable CO2 Incubator was effective for In Vitro Maturation (IVM) of bovIne, porcIne and mInke whale oocytes, and the effect of Maturation media supplemented with different hormones; porcIne follicle stimulatIng hormone (pFSH), estradiol-17β (E2), or pregnant mare's serum gonadotropIn (PMSG): human chorionic gonadotropIn (hCG) for mInke whale immature oocytes was also examIned. In Vitro Maturation rates of bovIne and porcIne oocytes cultured In the portable CO2 Incubator were not significantly different from the standard CO2 Incubator. In mInke whale IVM culture usIng the portable Incubator, the maximum expansion of cumulus mass was observed by pFSH/E2 and PMSG/hCG at the end of IVM culture. Moreover, the IVM culture period was shortened to 28-30 h from 96-120 h previously reported. The proportion of matured oocytes cultured In the medium supplemented with pFSH/E2 (26.7%) was significantly higher (P<0.05) than that with PMSG/hCG (6.9%). The present study Indicates that a portable CO2 Incubator is a useful device for mInke whale IVM culture on a research base ship, and the addition of pFSH/E2 Into an IVM medium enhanced cumulus expansion and the proportion of mInke whale matured oocytes.
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In Vitro Maturation and ultrastructural observation of cryopreserved mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 2000Co-Authors: Masatsugu Asada, Hajime Ishikawa, Yutaka Fukui, Toshihiro Mogoe, Miki Horii, Seiji OhsumiAbstract:MInke whale (Balaenoptera acutorostrata) follicular oocytes were cryopreserved by a slow-step freezIng procedure usIng ethylene glycol. The morphologically viable proportion of postthawed mInke whale follicular oocytes was 39.7%. The maturity of the animals (immature and mature whales) or the presence or absence of cumulus cells (CC) did not affect the proportion of morphologically viable oocytes. Postthawed oocytes were examIned for nuclear status after In Vitro Maturation. The presence of CC (29.1%) significantly enhanced (P < 0.05) the proportion of oocytes at metaphase I/anaphase I/telophase I stages compared to results with the absence of CC (13.5%). A total of 4 of 194 postthawed oocytes matured to the second metaphase stage after culture for 5.5 days with or without CC. The cryopreserved immature oocytes obtaIned from immature and mature whales were processed to examIne the ultrastructure by transmission electron microscopy. VaryIng ultrastructural damage to the cytoplasm was observed as a result of the cryopreservation procedures. These results show that 20-30% of cryopreserved mInke whale follicular oocytes can resume meiosis In Vitro, but damage Induced by the freezIng and thawIng procedures was observed.
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factors affectIng In Vitro Maturation of mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 1997Co-Authors: Yutaka Fukui, Hajime Ishikawa, Toshihiro Mogoe, Seiji OhsumiAbstract:Factors affectIng In Vitro Maturation (IVM) of mInke whale (Balaenopetra acutorostrata) follicular oocytes were Investigated. In experiment 1, recovery rates for oocytes from follicles of different sizes (small, 1-5 mm; medium, 6-10 mm; large, > or = 11 mm) were similar In both immature (54.7%) and mature (53.5%) females, and the follicular sizes did not affect recovery rate. Approximately half the oocytes recovered from small follicles In immature (55.5%) and mature (52.1%) whales were surrounded by at least a few layers of cumulus cells. Before culture, 71.7% and 61.2% of oocytes from immature and mature whales, respectively, were at the germInal vesicle stage. For IVM, effects of serum type, hormones, and additional cumulus cells (experiment 2) and effects of culture durations (24-120 h, experiment 3) were Investigated. The three factors Investigated In experiment 2 did not affect Maturation rates. TCM199 supplemented with fetal whale serum, hormones, and additional cumulus cells showed the highest rate (21.6%) of matured oocytes and resulted In a significant difference from the rate In medium with only fetal calf serum added (6.6%). The first oocyte with an extruded polar body was observed after 84 h of culture. The maximum rate (27.3%) of matured oocytes was obtaIned by 96 h of culture, but there was no significant difference In the proportions of matured oocytes between 90 and 120 h In culture. These results Indicate that In Vitro nuclear Maturation of immature follicular oocytes In mInke whales can be Induced.
Toshihiro Mogoe - One of the best experts on this subject based on the ideXlab platform.
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In Vitro Maturation and ultrastructural observation of cryopreserved mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 2000Co-Authors: Masatsugu Asada, Hajime Ishikawa, Yutaka Fukui, Toshihiro Mogoe, Miki Horii, Seiji OhsumiAbstract:MInke whale (Balaenoptera acutorostrata) follicular oocytes were cryopreserved by a slow-step freezIng procedure usIng ethylene glycol. The morphologically viable proportion of postthawed mInke whale follicular oocytes was 39.7%. The maturity of the animals (immature and mature whales) or the presence or absence of cumulus cells (CC) did not affect the proportion of morphologically viable oocytes. Postthawed oocytes were examIned for nuclear status after In Vitro Maturation. The presence of CC (29.1%) significantly enhanced (P < 0.05) the proportion of oocytes at metaphase I/anaphase I/telophase I stages compared to results with the absence of CC (13.5%). A total of 4 of 194 postthawed oocytes matured to the second metaphase stage after culture for 5.5 days with or without CC. The cryopreserved immature oocytes obtaIned from immature and mature whales were processed to examIne the ultrastructure by transmission electron microscopy. VaryIng ultrastructural damage to the cytoplasm was observed as a result of the cryopreservation procedures. These results show that 20-30% of cryopreserved mInke whale follicular oocytes can resume meiosis In Vitro, but damage Induced by the freezIng and thawIng procedures was observed.
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factors affectIng In Vitro Maturation of mInke whale balaenoptera acutorostrata follicular oocytes
Biology of Reproduction, 1997Co-Authors: Yutaka Fukui, Hajime Ishikawa, Toshihiro Mogoe, Seiji OhsumiAbstract:Factors affectIng In Vitro Maturation (IVM) of mInke whale (Balaenopetra acutorostrata) follicular oocytes were Investigated. In experiment 1, recovery rates for oocytes from follicles of different sizes (small, 1-5 mm; medium, 6-10 mm; large, > or = 11 mm) were similar In both immature (54.7%) and mature (53.5%) females, and the follicular sizes did not affect recovery rate. Approximately half the oocytes recovered from small follicles In immature (55.5%) and mature (52.1%) whales were surrounded by at least a few layers of cumulus cells. Before culture, 71.7% and 61.2% of oocytes from immature and mature whales, respectively, were at the germInal vesicle stage. For IVM, effects of serum type, hormones, and additional cumulus cells (experiment 2) and effects of culture durations (24-120 h, experiment 3) were Investigated. The three factors Investigated In experiment 2 did not affect Maturation rates. TCM199 supplemented with fetal whale serum, hormones, and additional cumulus cells showed the highest rate (21.6%) of matured oocytes and resulted In a significant difference from the rate In medium with only fetal calf serum added (6.6%). The first oocyte with an extruded polar body was observed after 84 h of culture. The maximum rate (27.3%) of matured oocytes was obtaIned by 96 h of culture, but there was no significant difference In the proportions of matured oocytes between 90 and 120 h In culture. These results Indicate that In Vitro nuclear Maturation of immature follicular oocytes In mInke whales can be Induced.
