• Journal of Embryo Transfer
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• v.24 no.3
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• pp.231-235
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• 2009

Oxygen consumption has been regarded as a useful indicator for assessment of mammalian embryo quality. However, there was no standard criterion to measure the oxygen consumption of embryos. Here, we measured oxygen consumption of bovine embryos at various developmental stages was measured using a scanning electrochemical microscopy (SECM). We found that the oxygen consumption significantly increased in blastocyst-stage embryos compared to other stage embryos (from 2-cell-stage to morula-stage), indicating that oxygen consumption reflects the cell number ($5.2{\sim}7.6{\times}10^{14}/mol\;s^{-1}$ versus $1.2{\sim}2.4{\times}10^{14}/mol\;s^{-1}$, p<0.05). In the morula-stage embryos, the oxygen consumption of in vivo derived embryos was significantly higher than that of in vitro produced embryos ($4.0{\times}10^{14}/mol\;s^{-1}$ versus $2.4{\times}10^{14}/mol\;s^{-1}$, p<0.05). However, there was no significant difference in consumption of oxygen by in vivo and in vitro-derived bovine blastocyst-stage embryos (p>0.05). In the frozen-thawed blastocyst-stage embryos, live embryos showed significantly higher oxygen consumption than dead embryos ($4.7{\times}10^{14}/mol\;s^{-1}$ versus $1.0{\times}10^{14}/mol\;s^{-1}$, p<0.05). These results indicate that the measuring oxygen consumption by SECM can be used to evaluate bovine embryo quality.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.463-469
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• 2010

Rice is a staple food for more than 50% of the world's population. Embryo comprises only 2 to 3% of the weight distribution of the entire pericarp but has higher concentration of vitamins, proteins, and essential fatty acids than the other parts of grains. Moreover, ${\alpha}$-tocoperol, ${\gamma}$-oryzanol, phytic acid and ${\gamma}$-aminobutric acid that have nutraceutical value are abundant. Increasing the volume of embryo assures the fortification of nutritional value of rice grain. We developed new black waxy giant embryo rice, Milyang 263 by crossing Josaengheugchal, a black waxy rice variety, and $ge^t$, a giant embryo mutant generated by tissue culture. The nutrient contents and physical properties of Milyang 263 were compared with several giant embryo mutants and normal embryo rice varieties. Changes in the nutrient properties after germination were also observed. Results indicated that this new black waxy giant embryo rice, Milyang 263, offers a promising source for improving nutritional quality of rice especially anthocyanin, essential minerals, and GABA.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.227-237
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• 2021

Artificial insemination of Korean native cattle (KNC) is the predominant method for breed improvement. However, industrialization of embryo production and transfer is necessary to utilize the genetic potential of KNC. The aim of this study was to examine associations between KNC donor cows and ovum pick-up (OPU) conditions, in-vivo oocyte recovery, and embryo development. Oocyte recovery and blastocyst development rates were higher at 50 and 60 mmHg OPU vacuum pressure than at 40 mmHg, which was, however, not significant. Regarding follicle growth, injection of 500 ㎍ GnRH 36 hours before OPU significantly increased the number of OPU oocytes from an average of 4.6 to 7.6 (P<0.05); no significant difference in embryo development rates was observed. Significant differences were observed in the numbers of OPU oocytes, embryo development rates, and transplantable blastocysts per individual among nine KNC donors (P<0.05). Furthermore, although there was no difference in OPU oocyte recovery intervals in approximately 2~8 weeks, the number of recovered oocytes significantly decreased at the 12-week interval (P<0.05); there was no difference in embryo development rates. The number of oocytes and embryonic development rates only tended to decrease until the seventh OPU session, but decreased significantly until the eighth session (P<0.05). The average pregnancy rate after transfer of OPU-derived in-vitro embryos into recipient cows was 41.8%. To improve the efficiency of OPU egg recovery and in-vitro embryo production, considering KNC donor characteristics, vacuum pressure of 60 mmHg, GnRH pretreatment to induce follicle growth, and effective OPU egg recovery up to seven times at intervals of 2~4 weeks appears to be most suitable. This study may facilitate the industrialization of KNC embryo production and transfer using high-quality cows.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.183-190
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• 2006

These studies were conducted to monitor developmental competence of follicular oocytes collected from the carcass of the high meat quality in Korean native cattle using each individual protocol of IVM, IVF and IVC. The follicular oocytes that were collected from the ovaries of the cow yielded 1, $1^+\;and\;1^{++}$ meat quality were matured, fertilized and cultured using each individual protocol of IVM, IVF and IVC. As results, the number of follicular oocytes collected from individual fundamentally-registered cows yielded 1, $1^+\;and\;1^{++}$ meat grade were 28.9, 28.8 and 29.6 per head, respectively. The rates of blastocyst formation after IVM, IVF and IVC were 27.2, 28.7 and 32.9% in the cows yielded 1, $1^+\;and\;1^{++}$ meat quality, respectively. The rate of blastocyst formation was 8.4 per head. The number of follicular oocytes collected from pedigree registered cows yielded 1, $1^+\;and\;1^{++}$ meat quality were 25.8, 27.1 and 27.0 per head, respectively. The rates of blastocyst formation were 23.0, 33.7 and 42.6% in the meat quality of 1, $1^+\;and\;1^{++}$ after in vitro-manipulation, respectively (p<0.05). The rate of blastocyst formation was 8.5 per head. In conclusion, these results suggest that in vitro embryo production system using individual culture system including IVM, IVF and IVC can make good use of the gene from the carcass of the high meat quality in Korean native cattle.

• Reproductive and Developmental Biology
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• v.33 no.1
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• pp.35-40
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• 2009

The objectives of this study was to evaluate the efficiency of the bacteria eliminated sperm by percoll gradient method on sperm quality and embryo cleavage in vitro in pig. The semen of miniature pig collected by gloved-hand method pre-warmed ($37^{\circ}C$) in thermos bottle, and separated by 65% percoll. Analysis of sperm ability was estimated by examining viability, capacitation and acrosome reaction using chlortetracycline (CTC) and the abnormality. Also, fertility of sperm was monitored with cleavage rate of embryo after IVF using separated and un-separated sperm by percoll. The result, viability of separated sperm was significantly(p<0.05) higher($83.6{\pm}$2.0 vs $59.0{\pm}4.4%$) than un-separated sperm. The results of CTC analysis showed the percentage of F- and B-patterned separated sperm was higher in separated that than un-separated sperm. On the contrary, the percentage of AR-patterned form unseparaed sperm was significantly(p<0.05) higher($13.6{\pm}0.8$ vs $8.1{\pm}0.6%$) than separated sperm. Also, abnormality of un-separated sperm was significantly(p<0.05) higher($2.2{\pm}0.4$ vs $16.8{\pm}2.8%$) than separated sperm. However, the cleavage rates of embryo using separated sperm by percoll and un-separated sperm had not significantly difference on 2 cell stage(9.25 vs 11.88%), 4 cell stage(26.76 vs 24.51%) and >4 cell stage(63.99 vs 63.61%) at 48h of IVF. Therefore, the sperm separated by percoll method showed improvement in sperm quality than un-separated sperm in miniature pig.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.271-280
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• 2018

Here, we evaluated the mode of programmed cell death during porcine oocyte maturation by comparing the two major pathways associated with programmed cell death, apoptosis (type I), and autophagy (type II). We investigated the expression and localization of major genes involved in autophagy and apoptosis at mRNA and protein levels. Furthermore, the effect of hormonal stimulation on autophagy and apoptosis was analyzed. We found that the activity of autophagy-associated genes was increased in the cumulus-oocyte complexes (COCs) following follicle-stimulating hormone (FSH) treatment, while the addition of luteinizing hormone (LH) reversed this effect. The expression of proteins associated with autophagy was the highest in FSH-treated COCs. On the other hand, caspase-3 protein level was maximum in COCs cultured with LH. The treatment with rapamycin resulted in the effect similar to that observed with FSH treatment and increased autophagy activity. Thus, hormonal stimulation of pig oocytes resulted in distinct patterns of maturation. The high-quality oocytes majorly relied on the type II pathway (autophagy), while the type I pathway (apoptosis) was more prominent among poor-quality oocytes. Further investigation of this distinction may allow the development of techniques to produce high-quality oocytes in porcine in vitro fertilization.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.3
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• pp.111-117
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• 2015

Objective: In order to increase the number of mature oocytes usable for intracytoplasmic sperm injection (ICSI), we aimed to investigate the effect of co-culturing granulosa cells (GCs) on human oocyte maturation in vitro, the fertilization rate, and embryo development. Methods: A total of 133 immature oocytes were retrieved and were randomly divided into two groups; oocytes that were cultured with GCs (group A) and oocytes that were cultured without GCs (group B). After in vitro maturation, only oocytes that displayed metaphase II (MII) underwent the ICSI procedure. The maturation and fertilization rates were analyzed, as well as the frequency of embryo development. Results: The mean age of the patients, their basal levels of follicle-stimulating hormone, and the number of oocytes recovered from the patients were all comparable between the two study groups. The number of oocytes that reached MII (mature oocytes) was 59 out of 70 (84.28%) in group A, compared to 41 out of 63 (65.07%) in group B (p=0.011). No significant difference between fertilization rates was found between the two study groups (p=0.702). The embryo development rate was higher in group A (33/59, 75%) than in group B (12/41, 42.85%; p=0.006). The proportion of highest-quality embryos and the blastocyst formation rate were significantly lower in group B than in group A (p=0.003 and p<0.001, respectively). Conclusion: The findings of the current study demonstrate that culturing immature human oocytes with GCs prior to ICSI improves the maturation rate and the likelihood of embryo development.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.175-180
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• 2015

Objective: Embryo loading (EL) is a major step in embryo transfer (ET) and affect on the success of in vitro fertilization (IVF). This study aimed to compare the effect of two different EL techniques on the rates of pregnancy and delivery in IVF/ET cycles. Methods: 207 fresh ET and 194 Frozen-thawed ET (FET) cycles were included in this retrospective study. Two groups (A and B) were defined based on the EL technique used. In group A, the entire catheter was flushed with Ham's F-10 medium. The embryos were then drawn into the catheter using one air bracket. In group B, $70{\mu}L$ of air was aspirated into the syringe and the catheter was flushed using Ham's F10 medium. The medium, air, embryos, air, and finally another layer of medium were then sequentially drawn into the catheter. The main outcome measures were the pregnancy and delivery rates. Results: The groups did not differ with respect to the etiology of infertility, the source of spermatozoa, the quality of the embryos, the type of EL catheter, and the ease of transfer. The pregnancy rate was similar between two groups. In fresh ET cycles, a higher delivery rate was observed in group B than it group A (78.1% vs. 60%, p=0.1). In FET cycles, the rate of delivery was significantly higher in group B than in group A to a nonsignificant extent (88.9% vs. 58.8%, p=0.06). Conclusion: EL techniques did not have a significant impact on the delivery rate in either fresh or FET cycles.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.1
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• pp.26-32
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• 2022

Objective: We investigated the effect of supplementing fertilization medium and/or culture medium with astaxanthin (AST) on the two phases of in vitro fertilization: gamete fertilization and embryo development. Methods: Mouse cumulus-oocyte complexes were divided into four groups with 5 µM AST added to the fertilization medium (group 3, n=300), culture medium (group 2, n=300), or both media (group 4, n=290). No AST was added to the control group (group 1, n=300). Results: The fertilization rate was significantly higher (p<0.001) in the groups using AST supplemented fertilization medium (group 3, 79.0%; group 4, 81.4%) than those without AST (group 1, 56.3%; group 2, 52.3%). The blastocyst rate calculated from the two-cell stage was significantly lower (p<0.001) in the groups using AST-supplemented embryo culture medium (group 2, 58.0%; group 4, 62.3%) than in those without AST (group 1, 82.8%; group 3, 79.8%). The blastocyst rate calculated from the number of inseminated oocytes was highest in group 3 (189/300, 63.0%) and lowest in group 2 (91/300, 30.3%) with statistical significance compared to other groups (p<0.001). There were significantly higher numbers of cells in the inner cell mass and trophectoderm, as well as significantly higher total blastocyst cell counts, in group 3 than in the control group. Conclusion: An increased blastocyst formation rate and high-quality blastocysts were found only in the fertilization medium that had been supplemented with AST. In contrast, AST supplementation of the embryo culture medium was found to impair embryo development.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.307-314
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• 2013

Embryos formed in vivo were collected from 171 donors housed in Chung Cheong Buk-Do Institute of Livestock and Veterinary Research of the Chungbuk community during the years 2009~2012. We evaluated annual embryo collection, effect of follicle stimulating hormone (FSH), controlled internal drug release (CIDR) and prostaglandin (PG) administration to the donor for superovulation and controlling the estrus cycle, seasonal effects of embryo collection and compared the number of embryos recovered as per the collection days and pregnancy rate. In all, 1,243 embryos were collected from 118 donors with an average of $7.31{\pm}5.35$ embryos per donor, out of which 69.4% were transferable. Dosages of FSH required for inducing superovulation in various donors were compared. Average number of embryos collected from donors administered with 30 AU of FSH ($7.13{\pm}5.74$ per donor) was not significantly different from that of donors who were given an injection of 24 AU of FSH ($7.53{\pm}4.91$ per donor). However, the percentage of transferable embryos in the 30AU FSH-administered group (63.2 %, 449 of 711) was higher than that in the 24AU FSH-administered group (77.8%, 414 of 532). In the group of donors under a natural estrus cycle, the FSH dose administered did not influence the number of transferable embryos produced ($7.49{\pm}6.25$ per donor for 30 AU of FSH vs $7.49{\pm}4.92$ per donor for 24 AU of FSH). However, in donors administered with CIDR and PG for controlling the estrus cycle, the FSH dose affected the average number of transferable embryos collected ($4.25{\pm}2.87$ per donor for 30 AU of FSH vs $8.50{\pm}6.36$ per donor for 24 AU of FSH). We collected embryos from donors 6, 7 or 8 days after artificial insemination (AI). Results showed that the percentage of transferable embryos among those collected 8 days after AI was significantly higher than that among embryos collected 6 or 7 days after AI. Seasonal variations did not affect number of recovered embryos and pregnancy rates in natural estrus cycle and CIDR treatment groups (48.28% and 42.55%) but higher than pregnancy rate of frozen embryos (19.63%). These results indicated that administration of FSH beyond a threshold dose (at least 24 AU) has no beneficial effect on the production embryos and that collection of embryos 7~8 days after AI is optimal for embryo recovery. CIDR treatment induced superovulation in short term and had no influence on the natural estrus cycle. Finally, although good-quality embryos were transferred, freezing significantly reduced the pregnancy rates after transfer.