• Journal of Embryo Transfer
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• v.33 no.4
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• pp.281-286
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• 2018

Zona pellucida (ZP), a primarily representative coat of mammalian egg and embryo, has an extremely heterogeneous morphology during different developmental stages. The objective of the present study was to compare the morphological changes of the ZP surface of immature, in vitro and in vivo matured canine oocytes by using scanning electron microscopy (SEM). Canine ovaries were collected from local veterinary hospitals to recover immature oocytes. The ovaries were sliced and the released cumulus oocyte complexes (COCs) were washed with TL-HEPES. The selected COCs were randomly divided into two groups, first group was processed immediately at immature state and the second group was processed 72 h after in vitro maturation, and compared with in vivo derived oocytes. Oocytes were fixed, critical point dried and examined under SEM. The diameters of oocyte and outer holes of the ZP were measured on a total of 249 oocytes; the results were analyzed using One-way ANOVA. Our results showed that, the diameter of immature oocytes significantly differed (p < 0.05) from that of in vivo matured oocytes ($79.60{\pm}0.77{\mu}m$ vs. $101.46{\pm}1.07{\mu}m$, respectively). Similarly, a significant difference (p < 0.05) in the diameters between those of in vitro and in vivo matured oocytes were found ($79.51{\pm}2.36{\mu}m$ vs. $101.46{\pm}1.07{\mu}m$, respectively). Moreover, the diameters of the outer holes of the ZP were significantly (p < 0.05) larger in in vivo matured ($1.48{\pm}0.42{\mu}m$) than in vitro matured for 72 and immature oocytes ($1.10{\pm}0.16$ and $0.43{\pm}0.12{\mu}m$, respectively). Taken together, these data indicates that the ZP surface is related to oocyte maturity in canine.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.75-85
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• 2019

Omega-3 α-linolenic acid and omega-6 linoleic acid are essential fatty acids for health maintenance of human and animals because they are not synthesized in vivo. The purpose of this study was to evaluate the effect of α-linolenic acid and linoleic acid supplementation on in vitro maturation and developmental potential of porcine oocytes. Various concentrations of α-linolenic acid and linoleic acid were added into in vitro maturation medium, and we evaluated the degree of cumulus expansion, oocyte nuclear-maturation rate, blastocyst rate, blastocyst quality, and levels of prostaglandin E₂, 17β-estradiol, and progesterone in the spent medium. High doses (100 μM) of α-linolenic acid and linoleic acid supplementation significantly inhibited cumulus expansion and oocyte nuclear maturation, and prostaglandin E₂ synthesis also significantly decreased compared with other groups (p < 0.05). Supplementation of 50 μM α-linolenic acid and 10 μM linoleic acid showed higher quality blastocysts in terms of high cell numbers and low apoptosis when compared with other groups (p < 0.05), and synthesis ratio of 17β-estradiol / progesterone also significantly increased compared with control group (3.59 ± 0.22 vs. 2.97 ± 0.22, 3.4 ± 0.28 vs. 2.81 ± 0.19, respectively; p < 0.05). Our results indicated that supplementation with appropriate levels of α-linolenic acid and linoleic acid beneficially affects the change of hormone synthesis (in particular, an appropriate increase in the 17β-estradiol / progesterone synthesis ratio) for controlling oocyte maturation, leading to improved embryo quality. However, high doses of α-linolenic acid and linoleic acid treatment results in detrimental effects.

• Journal of Embryo Transfer
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• v.10 no.1
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• pp.83-90
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• 1995

Production of calves after transfer of nuclear transplant embryos is the latest technology to be applied in commercial livestock breeding. The objective of this study was to establish an efficient procedure to produce offsprings from nuclear transplant embryos. The fusion rates (72.7% vs. 80.8%), cleavage rates (62.5% vs. 71.4%) and rates of development in vitro (12.0% vs. 15.2%) of nuclear transplant embryos were not significantly different between 30 and 40h maturation age of cytoplast. The in vivo and in vitro-derived embryos as nuclei donor were used in this system of bovine nuclear transplantation. Fusion rates of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (73.0 and 79.2%, respectively). The percentage of embryos reaching the morulae or blastocysts were 21.8% for in vivo-derived embryos and 11.9% for in vitro-derived embryos (p<0.01). Pregnancy rates after embryo transfer of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (45.9 and 40.5%, respectively). However, calving rates after embryo transfer of nuclear transplant embryos were significantly higher in the in vivo-derived embryos than in vitro (p<0.01). Further research for age of cytoplast and use of in vitro-derived embryos as nuclei donor is required in this system. In conclusion, these results clearly show that the use of in vitro-derived oocytes as recipient cytoplast can improve the nuclear transplant system for genetic progress in cattle.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.2
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• pp.119-125
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• 2016

Objective: The aim of this study was to report a case series of in vitro matured (IVM) oocyte freezing in gynecologic cancer patients undergoing radical surgery under time constraints as an option for fertility preservation (FP). Methods: Case series report. University-based in vitro fertilization center. Six gynecologic cancer patients who were scheduled to undergo radical surgery the next day were referred for FP. The patients had endometrial (n=2), ovarian (n=3), and double primary endometrial and ovarian (n=1) cancer. Ex vivo retrieval of immature oocytes from macroscopically normal ovarian tissue was followed by mature oocyte freezing after IVM or embryo freezing with intracytoplasmic sperm injection. Results: A total of 53 oocytes were retrieved from five patients, with a mean of 10.6 oocytes per patient. After IVM, a total of 36 mature oocytes were obtained, demonstrating a 67.9% maturation rate. With regard to the ovarian cancer patients, seven IVM oocytes were frozen from patient 3, who had stage IC cancer, whereas one IVM oocyte was frozen from patient 4, who had stage IV cancer despite being of a similar age. With regard to the endometrial cancer patients, 15 IVM oocytes from patient 1 were frozen. Five embryos were frozen after the fertilization of IVM oocytes from patient 6. Conclusion: Immature oocytes can be successfully retrieved ex vivo from macroscopically normal ovarian tissue before radical surgery. IVM oocyte freezing provides a possible FP option in patients with advanced-stage endometrial or ovarian cancer without the risk of cancer cell spillage or time delays.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.319-327
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• 2009

Follicular fluid meiosis-activating sterol (FF-MAS) has been suggested as a positive factor which could improve the oocyte quality and subsequent embryo development after in vitro fertilization. However, FF-MAS is a highly lipophilic substance and is hard to detect in studying the relationship between MAS and quality of oocyte maturation. The present study focused on the expression of lanosterol 14${\alpha}$-demethylase (LDM), a key enzyme that converts lanosterol to FF-MAS, on mouse oocyte maturation and its potency on development. LDM expression was strong in gonadotropin-primed germinal vesicle stage oocytes, weak after germinal vesicle breakdown (GVBD), and then strong in MII stage oocytes. The LDM-specific inhibitor azalanstat significantly inhibited oocyte fertilization (from 79.4% to 68.3%, p<0.05). Also, azalanstat (5 to 50 ${\mu}M$) decreased the percentage of blastocyst development dosedependently (from 78.7% to 23.4%, p<0.05). The specific inhibition of sterol ${\Delta}14$-reductase and ${\Delta}7$-reductase by AY9944 accumulates FF-MAS and could increase blastocyst development rates. Additionally, in the AY9944 group, the rate of inner cell mass (ICM)/ total cells was similar to that of in vivo development, but the rate was significantly decreased in azalanstat treatment. In conclusion, LDM, the key enzyme of FF-MAS production, may play an important role in fertilization and early development of the mouse embryo, especially in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.469-481
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• 1993

Gametic biotechnologies involve the procedures which are utilized for procuring reproductive success through the mimicry of in vivo events as in in vitro fertilization, embryo transfer etc. With the realization that the oviduct performs most of the procedures mimicked in vitro under normal in vivo situations, the need to master the oviduct therefore, becomes paramount. The oviduct being an exocrine gland (with its output of glycoproteins) and possibly an ecdocrine gland must be implicated in all the preimplantational procedures of reproduction, which include ovulation, oocyte maturation, sperm capacitation, gametic and embryonal nutrition, fertilization, and implantation. The evidences in the literature for the implication of the oviduct in these processes are examined. It is concluded that there is a need for the mastery of oviductual activity in order to maximize the successes of the procedures in vitro, and provide gametic manipulations which will have high success rates in implantation that is the ultimate after of in vitro fertilization for reproductive success.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.133-142
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• 2002

The objective of this study was to examine maturation, fertilization and developmental rate of the in vitro-grown mouse oocytes, and to compare these results with those of oocytes grown and matured in vivo. The preantral follicles isolated from 12-day-old mice were cultured on Transwell-COL membrane inserts. After in vitro growth and maturation, 72.5 % of oocytes grown in vitro produced polar body which can be comparable to in vivo growth (70.5 %). However, the mean oocyte diameter of the in vitro group (69.6$\pm$2.1$\mu$m) was smaller than that of the in vivo group (73.3$\pm$3.0$\mu$m). The fertilization rate was significantly lower (p<0.05) in the in vitro group (76.5%) than in the in vivo group (90.2%), however, there was no difference in the percentage of monospermic and polyspermic oocytes between two groups. The capacities of in vitro grown ova to cleave and develop to blastocyst were (57.8 and 14.4%, respectively) significantly lower (p<0.001) than those of the in vivo counterpart (84.4 and 56.6%, respectively). Moreover, the mean number of cells per blastocyst was significantly lower (p<0.05) in the in vitro group (39.0$\pm$10.8) than in the in vivo group (60.5$\pm$12.5). Live young were produced from transferred 2-cell embryos derived from in vitro-grown and matured oocytes. In conclusion, the results show that in vitro-grown oocytes did not achieve the developmental capacity of in vitro-grown oocytes.

• Reproductive and Developmental Biology
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• v.41 no.1
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• pp.17-23
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• 2017

The oocyte undergoes various events during in vitro maturation (IVM) and subsequence development. One of the events is production of reactive oxygen species (ROS) that is a normal process of cell metabolism. But imbalances between ROS production and antioxidant systems induce oxidative stress that negatively affect to mammalian reproductive process. In vitro environments, in vitro matured oocytes have many problems, such as excessive production of ROS and imperfect cytoplasmic maturation. Therefore, in vitro matured oocytes still have lower maturation rates and developmental competence than in vivo matured oocytes. In order to improve the IVM and in vitro culture (IVC) system, antioxidants, vitamins were added to the IVM, IVC medium. Antioxidant supplementation was effective in controlling the production of ROS and it continues to be explored as a potential strategy to overcome mammalian reproductive disorders. Based on these studies, we expect that the use of antioxidants in porcine oocytes could improved maturation and development rates.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.253-259
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• 2008

Human follicular fluid (HFF) is the in vivo microenvironment for oocyte maturation and includes a variety of proteins that could be involved in oocyte development and fertilization. We therefore used a proteomic approach to identify new HFF proteins. HFF from mature human follicles was obtained from five women following oocyte collection for in vitro fertilization (IVF). Ethanol-precipitated HFF run on two-dimensional gel electrophoresis (2DE) produced approximately 250 Coomassie brilliant blue-stained spots, 64 of which were identified using matrix-assisted laser desorption/ionization-mass spectrometry (MALDIMS). In this study, several proteins including complement factor H, inter-${\alpha}$ (globulin) inhibitor H4, inter-${\alpha}$-trypsin inhibitor heavy chain H4 precursor, human zinc-${\alpha}$-2-glycoprotein chain B, PRO2619, PRO02044, and complex-forming glycoprotein HC were new proteins that have not been previously reported in HFF using proteomic methods. Additionally, we identified alloalbumin venezia for the first time from trichloroacetic acid (TCA)-precipitated HFF. These HFF proteins could serve as new biomarkers for important human reproductive processes.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.2
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• pp.47-53
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• 2023

Despite numerous advances in in-vitro embryo production (IVP), many documented factors have been shown to influence the development of mammalian preimplantation embryos and the success of IVP. In this sense, elevated levels of reactive oxygen species (ROS) correlate with poor outcomes in assisted reproductive technologies (ART) due to oxidative stress (OS), which results from an imbalance between ROS production and neutralization. Indeed, excessive production of ROS compromises the structural and functional integrity of gametes and embryos both in vivo and in vitro. In particular, OS damages proteins, lipids, and DNA and accelerates cell apoptosis. Several in-vivo and in-vitro studies report an improvement in qualityrelevant parameters after the use of various antioxidants. In this review, we focus on OS and the source of free radicals and their effects on oocytes, sperm, and the embryo during IVP. In addition, antioxidants and their important role in IVP, supplementation during oocyte in vitro maturation (IVM), in vitro culture (IVC), and semen extenders were discussed. Nevertheless, various methods for determining the level of ROS in germ cells have been briefly described. Still, it is crucial to develop standardized antioxidant supplement systems to improve overall IVP success. Further studies should explore the safety, efficacy, mechanism of action, and combination of different antioxidants to improve IVP outcomes.