• Development and Reproduction
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• v.13 no.3
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• pp.145-153
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• 2009

Previously, we obtained the list of genes differentially expressed between GV and MII oocytes. Out of the list, we focused on functional analysis of Zap70 in the present study, because it has been known to be expressed only in immune cells. This is the first report about the expression and its function of Zap70 in the oocytes. Synthetic 475 bp Zap70 dsRNA was microinjected into the GV oocytes, and the oocytes were cultured in vitro. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression levels of transcripts of three kinases, Erk1/2, JNK, and p38, were determined. Zap70 is highly expressed in immature GV oocytes, and gradually decreased as oocyte matured. When dsRNA of Zap70 was injected into the GV oocytes, Zap70 mRNA specifically and completely decreased by 2 hr and its protein expression also decreased significantly. Absence of Zap70 resulted in maturation inhibition at meiosis I (57%) with abnormalities in meiotic spindle formation and chromosome rearrangement. Concurrently, mRNA expression of Erk2, JNK, and p38, were affected by Zap70 RNAi. Therefore, we concluded that Zap70 is involved in MI-MII transition by affecting expression of MAP kinases.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.1
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• pp.53-60
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• 2011

Objective: This study was carried out to compare the clinical outcome of elective single cleavage-embryo transfer (eSCET) to that of elective single blastocyst-embryo transfer (eSBET) in human IVF-ET. Methods: This study was a retrospective study which analyzed for 614 women who visited the Daegu Maria Clinic from August 2008 to December 2009. All were under 37 years old and had more than 8 mm of endometrial thickness on the day of hCG administration and at least one good quality embryo on day 3. The eSCETs were performed on day 3 (n=450) and the eSBETs were conducted on day 5 (n=164). Results: The numbers of retrieved oocytes, fertilized oocytes, and day 3 good quality embryos were significantly lower in the eSCET group (12.1${\pm}$6.0, 8.2${\pm}$4.6, and 4.2${\pm}$3.1, respectively) compared to the eSBET group (16.7${\pm}$7.2, 12.1${\pm}$5.0, and 8.5${\pm}$4.5, respectively; p<0.001). However, the clinical pregnancy, implantation, on-going pregnancy, and live birth rates of the eSCET group (46.7, 46.9, 40.0, and 36.7%, respectively) were not statistically different from those of the eSBET group (51.2, 51.8, 45.1, and 43.9%, respectively; p=0.318, 0.278, 0.254, and 0.103, respectively). Conclusion: These results suggested that elective single embryo transfer should be performed regardless of the developmental stage to women less than 37 years old who had more than 8 mm of endometrial thickness on the hCG administration day and at least one good quality embryo on day 3 in order to reduce the twin pregnancy rate without reducing the whole pregnancy rate.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.1
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• pp.22-29
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• 2019

Objective: As paternal age increases, the quality of sperm decreases due to increased DNA fragmentation and aneuploidy. Higher levels of structural chromosomal aberrations in the gametes ultimately decrease both the morphologic quality of embryos and the pregnancy rate. In this study, we investigated whether paternal age affected the euploidy rate. Methods: This study was performed using the medical records of patients who underwent in vitro fertilization (IVF) procedures with preimplantation genetic screening (PGS) from January 2016 to August 2017 at a single center. Based on their morphological grade, embryos were categorized as good- or poor-quality blastocysts. The effects of paternal age were elucidated by adjusting for maternal age. Results: Among the 571 total blastocysts, 219 euploid blastocysts were analyzed by PGS (38.4%). When the study population was divided into four groups according to both maternal and paternal age, significant differences were only noted between groups that differed by maternal age (group 1 vs. 3, p= 0.031; group 2 vs. 4, p= 0.027). Further analysis revealed no significant differences in the euploidy rate among the groups according to the morphological grade of the embryos. Conclusion: Paternal age did not have a significant impact on euploidy rates when PGS was performed. An additional study with a larger sample size is needed to clarify the effects of advanced paternal age on IVF outcomes.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.4
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• pp.307-319
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• 2010

Objective: Vitrification requires a high concentration of cyroprotectant (CPA) and an elevated cooling speed to avoid ice crystal formation. We have evaluated the effect of different combinations of cooling rate and CPA on embryonic integrity (developmental competence) in order to increase the efficiency of vitrification without impairing embryo viabilit. We hypothesized that the combination of CPA or the increase of cooling rates can reduce the concentration of toxic CPA for vitrification. As consequently, we performed experiments to evaluate the effect of various composition of CPA or slush nitrogen ($SN_2$) on the mouse embryonic development following vitrification using low CPA concentration. Methods: Vitrification of mouse embryos was performed with EM grid using liquid nitrogen ($LN_2$) or $SN_2$ and different composition of CPAs, ethylene glycol (EG) and dimethylsulfoxide (DMSO). After vitrification-warming process, their survival and blastocyst formation rates were examined. For analyzing long-term effect, these blastocysts were transferred into the uterus of foster mothers. Results: Survival and blastocyst formation rates of vitrified embryos were higher in EG+DMSO group than those in EG only. Furthermor, the group using $SN_2$ with a lower CPA concentration showed a higher survival of embryos and developmental rates than group using $LN_2$. Conclusion: The combination of EG and DMSO as CPAs may enhance the survival of mouse embryos and further embryonic development after vitrification. $SN_2$ can generate high survival and developmental rate of vitrified/warmed mouse embryos when a lower concentration of CPA was applied. Therefore, these systems may contribute in the improvement of cryopreservation for fertility preservation.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.97-101
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• 1994

The fertilities of pyloploidy mulberries and the germination abilities and shape of poliploidy mulberry seeds fructified by natural cross were investigated and the results are as follows. Regarding the size of seeds, that of the tetraploid was the biggest and that of hexaploid was the smallest among the investigated polyploids. Those of diploid and triploid ranged between those of tetraploid and hexaploid. The fertilization rates of the varieties of Shinkwangppong and Cheongunppong, which were triploid, were 25.4 and 55.0%, respectively, and Shinkwangppong showed 10.2% of cross rate, but Cheongunppong did not have germination ability. The tetraploid seeds showed 61~68% of fertility and 30~54% of cross rate. The Puksan No. 2, which is hexaploid, had about 43% and 7% in fertility and cross rate, respectively. The germination abilities of floating seeds of diploid and tetraploid were comparatively high, but the floating seeds of triploid and hexaploid did not have germination ability. The seeds of diploid had a high fertility of 81~95% and a comparatively high cross rate of 47~74%.

• Reproductive and Developmental Biology
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• v.38 no.1
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• pp.53-62
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• 2014

The objective of this study was to investigate the relationship between fertility and protein pattern change using in vitro fertilization, analysis of sperm characteristics and two-dimensional gel electrophoresis in different pig types. In results, the viability and mitochondria integrity of sperm were higher significantly (p<0.05) but the portions of acrosome reaction was lower significantly (p<0.05) in Duroc and $F_1$ (potbellied ${\times}$ PWG miniature pig) than PWG miniature. On in vitro fertilization to investigate fertility, the fertility of $F_1$ semen war higher significantly (p<0.05) than in Duroc and PWG miniature pig. On the other hand, protein patterns showed similar function among the different boar semen. Especially, the heat shock 70 kDa 1-like and G patch domain-containing protein 4 were significantly (p<0.05) higher expressed in $F_1$ than in Duroc and PWG miniature pig. The proteins associated with mitochondria in Duroc were significantly (p<0.05) higher expressed than in $F_1$ and PWG miniature pig. The developmental rates to blastocyst stage of oocytes fertilized with sperm of $F_1$ pig were significantly (p<0.05) higher than in PWG miniature pig. However, phosphoglycerate kinase 2 and zinc finger protein 431 were significantly (p<0.05) higher expressed in PWG miniature pig than in $F_1$ and Duroc pigs. In conclusion, the results of the present study indicate that different proteins were expressed in different pig types, and were associated with a sperm functions and embryo development.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.1
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• pp.22-29
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• 2015

Objective: Sperm must be properly prepared in in vitro fertilization (IVF)-embryo transfer (ET) programs in order to control the fertilization rate and ensure that embryos are of high quality and have appropriate developmental abilities. The objective of this study was to determine the most optimal sperm preparation method for IVF. Methods: Patients less than 40 years of age who participated in a fresh IVF-ET cycle from November 2012 to March 2013 were included in this study. Poor responders with less than three mature oocytes were excluded. Ham's F-10 medium or sperm-washing medium (SWM) was used in combination with the density-gradient centrifugation/swim-up (DGC-SUP) or SUP methods for sperm preparation. A total of 429 fresh IVF-ET cycles were grouped according to the media and methods used for sperm preparation and retrospectively analyzed (DGC-SUP/Ham's F-10, n=82; DGC-SUP/SWM, n=43; SUP/Ham's F-10, n=181; SUP/SWM, n=123). Results: There were no significant differences among these four groups with respect to the mean age of the female partners, duration of infertility, number of previous IVF cycles, and retrieved oocytes. We determined that both the DGC-SUP and SUP methods for sperm preparation from whole semen, using either Ham's F-10 or SWM media, result in comparable clinical outcomes, including fertilization and pregnancy rates. Conclusion: We suggest that both media and both methods for sperm preparation can be used for selecting high-quality sperm for assistive reproductive technology programs.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.191-198
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• 2010

Uterine myomas are heterogeneous tumors in composition, size, location, and number; variation in any of these factors could possibly alter the effect on a woman's fertility status. The effect of myomas on fertility has been the subject of many studies. However, a definitive answer is still missing. The location and size of the myomas are the two parameters that influence the success of a future pregnancy. Subserosal myomas seem to have little effect on reproductive outcome. Myomas that compress the uterine cavity with an intramural portion and submucosal myomas significantly reduce pregnancy rates, and should be removed before assisted reproductive techniques are performed. Patients with intramural myomas also may have a poorer reproductive outcome, but the lacks of quality evaluations make this conclusion tenuous at best. Removal of myomas with an intra-cavitary component seems to be of benefit. However there are as yet no data to support myomectomy in the treatment of intramural myomas to improve fertility outcomes. Treatment modality for myomas located at intramural sites should be determined according to clinical status of the patient and doctor's experience.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.186-192
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• 2011

Objective: Since IVF program was first established, various types of media and culture systems have been developed either in-house or commercially. The aim of this study was to compare the efficacy of in-house Maria Research Center (MRC) media to that of commercially available Sydney IVF media in human day 3 embryo transfer cycles. Methods: Three hundred sixty nine couples were included in this prospective, randomized, and comparative study. All couples undergoing IVF treatment at the Maria Fertility Hospital were randomly assigned to either Sydney IVF (n=178) or MRC (n=191) media. Results: No difference was observed between the MRC media and Sydney IVF media groups with respect to fertilization rate (74.4% vs. 75.5%). The clinical pregnancy and implantation rates of MRC media (47.1% and 20.0%, respectively) were also similar to those of Sydney IVF media (44.4% and 19.4%, respectively). However, the proportion of embryos with good quality on day 3 was significantly higher in the MRC media group than the Sydney IVF media group (50.2% vs. 43.2%) ($p$ <0.05). Conclusion: MRC media were as effective as Sydney IVF media for sustaining embryo development and pregnancy rates. The present study implies that MRC media can be a suitable alternative to commercially available media for human IVF-ET program.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.275-278
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• 1992

One hundred sixty three (163) animals were used in $2{\times}2$ and $3{\times}2$ factorial experiment in randomized complete block design (RCBD) to determine the effect of clitoral stimulation during timed inseminations on the fertility of Philippine swamp buffaloes (carabaos). There were 3 separate trials conducted with two treatment groups per trial : control and with 30 second clitoral stimulation after each insemination. Parity, tone of uterus and site of semen deposition were also used as criteria in subdividing the main groups. The pregnancy rates of animals that received clitoral stimulation were significantly (p<0.05 or p<0.01) higher than those of control for both caraheifers (52.98 vs 31.41%) and caracows (52.68 vs 27.07%) ; under all uterine conditions : tone 1 (53.33 vs 31.75%), tone 2 (35.83 vs 22.82%) and tone 3 (75.65 vs 42.44%) ; and in both site of semen placement, cervix (43.99 vs 22.85%) and uterus (60.92% vs 37.81%). Fertility was also significantly (p<0.05) higher when semen was deposited in the uterus (49.37%) than in the cervix (33.42%). Interaction effect was insignificant. Clitoral stimulation should be utilized as a routine procedure following artificial insemination in carabaos.